Merge branch 'master' of git://git.creatis.insa-lyon.fr/clitk

[clitk.git] / utilities / pugixml / pugixml.cpp

/**
 * pugixml parser - version 1.9
 * --------------------------------------------------------
 * Copyright (C) 2006-2018, by Arseny Kapoulkine (arseny.kapoulkine@gmail.com)
 * Report bugs and download new versions at http://pugixml.org/
 *
 * This library is distributed under the MIT License. See notice at the end
 * of this file.
 *
 * This work is based on the pugxml parser, which is:
 * Copyright (C) 2003, by Kristen Wegner (kristen@tima.net)
 */

#ifndef SOURCE_PUGIXML_CPP
#define SOURCE_PUGIXML_CPP

#include "pugixml.hpp"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <limits.h>

#ifdef PUGIXML_WCHAR_MODE
#       include <wchar.h>
#endif

#ifndef PUGIXML_NO_XPATH
#       include <math.h>
#       include <float.h>
#endif

#ifndef PUGIXML_NO_STL
#       include <istream>
#       include <ostream>
#       include <string>
#endif

// For placement new
#include <new>

#ifdef _MSC_VER
#       pragma warning(push)
#       pragma warning(disable: 4127) // conditional expression is constant
#       pragma warning(disable: 4324) // structure was padded due to __declspec(align())
#       pragma warning(disable: 4702) // unreachable code
#       pragma warning(disable: 4996) // this function or variable may be unsafe
#endif

#if defined(_MSC_VER) && defined(__c2__)
#       pragma clang diagnostic push
#       pragma clang diagnostic ignored "-Wdeprecated" // this function or variable may be unsafe
#endif

#ifdef __INTEL_COMPILER
#       pragma warning(disable: 177) // function was declared but never referenced
#       pragma warning(disable: 279) // controlling expression is constant
#       pragma warning(disable: 1478 1786) // function was declared "deprecated"
#       pragma warning(disable: 1684) // conversion from pointer to same-sized integral type
#endif

#if defined(__BORLANDC__) && defined(PUGIXML_HEADER_ONLY)
#       pragma warn -8080 // symbol is declared but never used; disabling this inside push/pop bracket does not make the warning go away
#endif

#ifdef __BORLANDC__
#       pragma option push
#       pragma warn -8008 // condition is always false
#       pragma warn -8066 // unreachable code
#endif

#ifdef __SNC__
// Using diag_push/diag_pop does not disable the warnings inside templates due to a compiler bug
#       pragma diag_suppress=178 // function was declared but never referenced
#       pragma diag_suppress=237 // controlling expression is constant
#endif

#ifdef __TI_COMPILER_VERSION__
#       pragma diag_suppress 179 // function was declared but never referenced
#endif

// Inlining controls
#if defined(_MSC_VER) && _MSC_VER >= 1300
#       define PUGI__NO_INLINE __declspec(noinline)
#elif defined(__GNUC__)
#       define PUGI__NO_INLINE __attribute__((noinline))
#else
#       define PUGI__NO_INLINE
#endif

// Branch weight controls
#if defined(__GNUC__) && !defined(__c2__)
#       define PUGI__UNLIKELY(cond) __builtin_expect(cond, 0)
#else
#       define PUGI__UNLIKELY(cond) (cond)
#endif

// Simple static assertion
#define PUGI__STATIC_ASSERT(cond) { static const char condition_failed[(cond) ? 1 : -1] = {0}; (void)condition_failed[0]; }

// Digital Mars C++ bug workaround for passing char loaded from memory via stack
#ifdef __DMC__
#       define PUGI__DMC_VOLATILE volatile
#else
#       define PUGI__DMC_VOLATILE
#endif

// Integer sanitizer workaround; we only apply this for clang since gcc8 has no_sanitize but not unsigned-integer-overflow and produces "attribute directive ignored" warnings
#if defined(__clang__) && defined(__has_attribute)
#       if __has_attribute(no_sanitize)
#               define PUGI__UNSIGNED_OVERFLOW __attribute__((no_sanitize("unsigned-integer-overflow")))
#       else
#               define PUGI__UNSIGNED_OVERFLOW
#       endif
#else
#       define PUGI__UNSIGNED_OVERFLOW
#endif

// Borland C++ bug workaround for not defining ::memcpy depending on header include order (can't always use std::memcpy because some compilers don't have it at all)
#if defined(__BORLANDC__) && !defined(__MEM_H_USING_LIST)
using std::memcpy;
using std::memmove;
using std::memset;
#endif

// Some MinGW/GCC versions have headers that erroneously omit LLONG_MIN/LLONG_MAX/ULLONG_MAX definitions from limits.h in some configurations
#if defined(PUGIXML_HAS_LONG_LONG) && defined(__GNUC__) && !defined(LLONG_MAX) && !defined(LLONG_MIN) && !defined(ULLONG_MAX)
#       define LLONG_MIN (-LLONG_MAX - 1LL)
#       define LLONG_MAX __LONG_LONG_MAX__
#       define ULLONG_MAX (LLONG_MAX * 2ULL + 1ULL)
#endif

// In some environments MSVC is a compiler but the CRT lacks certain MSVC-specific features
#if defined(_MSC_VER) && !defined(__S3E__)
#       define PUGI__MSVC_CRT_VERSION _MSC_VER
#endif

// Not all platforms have snprintf; we define a wrapper that uses snprintf if possible. This only works with buffers with a known size.
#if __cplusplus >= 201103
#       define PUGI__SNPRINTF(buf, ...) snprintf(buf, sizeof(buf), __VA_ARGS__)
#elif defined(PUGI__MSVC_CRT_VERSION) && PUGI__MSVC_CRT_VERSION >= 1400
#       define PUGI__SNPRINTF(buf, ...) _snprintf_s(buf, _countof(buf), _TRUNCATE, __VA_ARGS__)
#else
#       define PUGI__SNPRINTF sprintf
#endif

// We put implementation details into an anonymous namespace in source mode, but have to keep it in non-anonymous namespace in header-only mode to prevent binary bloat.
#ifdef PUGIXML_HEADER_ONLY
#       define PUGI__NS_BEGIN namespace pugi { namespace impl {
#       define PUGI__NS_END } }
#       define PUGI__FN inline
#       define PUGI__FN_NO_INLINE inline
#else
#       if defined(_MSC_VER) && _MSC_VER < 1300 // MSVC6 seems to have an amusing bug with anonymous namespaces inside namespaces
#               define PUGI__NS_BEGIN namespace pugi { namespace impl {
#               define PUGI__NS_END } }
#       else
#               define PUGI__NS_BEGIN namespace pugi { namespace impl { namespace {
#               define PUGI__NS_END } } }
#       endif
#       define PUGI__FN
#       define PUGI__FN_NO_INLINE PUGI__NO_INLINE
#endif

// uintptr_t
#if (defined(_MSC_VER) && _MSC_VER < 1600) || (defined(__BORLANDC__) && __BORLANDC__ < 0x561)
namespace pugi
{
#       ifndef _UINTPTR_T_DEFINED
        typedef size_t uintptr_t;
#       endif

        typedef unsigned __int8 uint8_t;
        typedef unsigned __int16 uint16_t;
        typedef unsigned __int32 uint32_t;
}
#else
#       include <stdint.h>
#endif

// Memory allocation
PUGI__NS_BEGIN
        PUGI__FN void* default_allocate(size_t size)
        {
                return malloc(size);
        }

        PUGI__FN void default_deallocate(void* ptr)
        {
                free(ptr);
        }

        template <typename T>
        struct xml_memory_management_function_storage
        {
                static allocation_function allocate;
                static deallocation_function deallocate;
        };

        // Global allocation functions are stored in class statics so that in header mode linker deduplicates them
        // Without a template<> we'll get multiple definitions of the same static
        template <typename T> allocation_function xml_memory_management_function_storage<T>::allocate = default_allocate;
        template <typename T> deallocation_function xml_memory_management_function_storage<T>::deallocate = default_deallocate;

        typedef xml_memory_management_function_storage<int> xml_memory;
PUGI__NS_END

// String utilities
PUGI__NS_BEGIN
        // Get string length
        PUGI__FN size_t strlength(const char_t* s)
        {
                assert(s);

        #ifdef PUGIXML_WCHAR_MODE
                return wcslen(s);
        #else
                return strlen(s);
        #endif
        }

        // Compare two strings
        PUGI__FN bool strequal(const char_t* src, const char_t* dst)
        {
                assert(src && dst);

        #ifdef PUGIXML_WCHAR_MODE
                return wcscmp(src, dst) == 0;
        #else
                return strcmp(src, dst) == 0;
        #endif
        }

        // Compare lhs with [rhs_begin, rhs_end)
        PUGI__FN bool strequalrange(const char_t* lhs, const char_t* rhs, size_t count)
        {
                for (size_t i = 0; i < count; ++i)
                        if (lhs[i] != rhs[i])
                                return false;

                return lhs[count] == 0;
        }

        // Get length of wide string, even if CRT lacks wide character support
        PUGI__FN size_t strlength_wide(const wchar_t* s)
        {
                assert(s);

        #ifdef PUGIXML_WCHAR_MODE
                return wcslen(s);
        #else
                const wchar_t* end = s;
                while (*end) end++;
                return static_cast<size_t>(end - s);
        #endif
        }
PUGI__NS_END

// auto_ptr-like object for exception recovery
PUGI__NS_BEGIN
        template <typename T> struct auto_deleter
        {
                typedef void (*D)(T*);

                T* data;
                D deleter;

                auto_deleter(T* data_, D deleter_): data(data_), deleter(deleter_)
                {
                }

                ~auto_deleter()
                {
                        if (data) deleter(data);
                }

                T* release()
                {
                        T* result = data;
                        data = 0;
                        return result;
                }
        };
PUGI__NS_END

#ifdef PUGIXML_COMPACT
PUGI__NS_BEGIN
        class compact_hash_table
        {
        public:
                compact_hash_table(): _items(0), _capacity(0), _count(0)
                {
                }

                void clear()
                {
                        if (_items)
                        {
                                xml_memory::deallocate(_items);
                                _items = 0;
                                _capacity = 0;
                                _count = 0;
                        }
                }

                void* find(const void* key)
                {
                        if (_capacity == 0) return 0;

                        item_t* item = get_item(key);
                        assert(item);
                        assert(item->key == key || (item->key == 0 && item->value == 0));

                        return item->value;
                }

                void insert(const void* key, void* value)
                {
                        assert(_capacity != 0 && _count < _capacity - _capacity / 4);

                        item_t* item = get_item(key);
                        assert(item);

                        if (item->key == 0)
                        {
                                _count++;
                                item->key = key;
                        }

                        item->value = value;
                }

                bool reserve(size_t extra = 16)
                {
                        if (_count + extra >= _capacity - _capacity / 4)
                                return rehash(_count + extra);

                        return true;
                }

        private:
                struct item_t
                {
                        const void* key;
                        void* value;
                };

                item_t* _items;
                size_t _capacity;

                size_t _count;

                bool rehash(size_t count);

                item_t* get_item(const void* key)
                {
                        assert(key);
                        assert(_capacity > 0);

                        size_t hashmod = _capacity - 1;
                        size_t bucket = hash(key) & hashmod;

                        for (size_t probe = 0; probe <= hashmod; ++probe)
                        {
                                item_t& probe_item = _items[bucket];

                                if (probe_item.key == key || probe_item.key == 0)
                                        return &probe_item;

                                // hash collision, quadratic probing
                                bucket = (bucket + probe + 1) & hashmod;
                        }

                        assert(false && "Hash table is full"); // unreachable
                        return 0;
                }

                static PUGI__UNSIGNED_OVERFLOW unsigned int hash(const void* key)
                {
                        unsigned int h = static_cast<unsigned int>(reinterpret_cast<uintptr_t>(key));

                        // MurmurHash3 32-bit finalizer
                        h ^= h >> 16;
                        h *= 0x85ebca6bu;
                        h ^= h >> 13;
                        h *= 0xc2b2ae35u;
                        h ^= h >> 16;

                        return h;
                }
        };

        PUGI__FN_NO_INLINE bool compact_hash_table::rehash(size_t count)
        {
                size_t capacity = 32;
                while (count >= capacity - capacity / 4)
                        capacity *= 2;

                compact_hash_table rt;
                rt._capacity = capacity;
                rt._items = static_cast<item_t*>(xml_memory::allocate(sizeof(item_t) * capacity));

                if (!rt._items)
                        return false;

                memset(rt._items, 0, sizeof(item_t) * capacity);

                for (size_t i = 0; i < _capacity; ++i)
                        if (_items[i].key)
                                rt.insert(_items[i].key, _items[i].value);

                if (_items)
                        xml_memory::deallocate(_items);

                _capacity = capacity;
                _items = rt._items;

                assert(_count == rt._count);

                return true;
        }

PUGI__NS_END
#endif

PUGI__NS_BEGIN
#ifdef PUGIXML_COMPACT
        static const uintptr_t xml_memory_block_alignment = 4;
#else
        static const uintptr_t xml_memory_block_alignment = sizeof(void*);
#endif

        // extra metadata bits
        static const uintptr_t xml_memory_page_contents_shared_mask = 64;
        static const uintptr_t xml_memory_page_name_allocated_mask = 32;
        static const uintptr_t xml_memory_page_value_allocated_mask = 16;
        static const uintptr_t xml_memory_page_type_mask = 15;

        // combined masks for string uniqueness
        static const uintptr_t xml_memory_page_name_allocated_or_shared_mask = xml_memory_page_name_allocated_mask | xml_memory_page_contents_shared_mask;
        static const uintptr_t xml_memory_page_value_allocated_or_shared_mask = xml_memory_page_value_allocated_mask | xml_memory_page_contents_shared_mask;

#ifdef PUGIXML_COMPACT
        #define PUGI__GETHEADER_IMPL(object, page, flags) // unused
        #define PUGI__GETPAGE_IMPL(header) (header).get_page()
#else
        #define PUGI__GETHEADER_IMPL(object, page, flags) (((reinterpret_cast<char*>(object) - reinterpret_cast<char*>(page)) << 8) | (flags))
        // this macro casts pointers through void* to avoid 'cast increases required alignment of target type' warnings
        #define PUGI__GETPAGE_IMPL(header) static_cast<impl::xml_memory_page*>(const_cast<void*>(static_cast<const void*>(reinterpret_cast<const char*>(&header) - (header >> 8))))
#endif

        #define PUGI__GETPAGE(n) PUGI__GETPAGE_IMPL((n)->header)
        #define PUGI__NODETYPE(n) static_cast<xml_node_type>((n)->header & impl::xml_memory_page_type_mask)

        struct xml_allocator;

        struct xml_memory_page
        {
                static xml_memory_page* construct(void* memory)
                {
                        xml_memory_page* result = static_cast<xml_memory_page*>(memory);

                        result->allocator = 0;
                        result->prev = 0;
                        result->next = 0;
                        result->busy_size = 0;
                        result->freed_size = 0;

                #ifdef PUGIXML_COMPACT
                        result->compact_string_base = 0;
                        result->compact_shared_parent = 0;
                        result->compact_page_marker = 0;
                #endif

                        return result;
                }

                xml_allocator* allocator;

                xml_memory_page* prev;
                xml_memory_page* next;

                size_t busy_size;
                size_t freed_size;

        #ifdef PUGIXML_COMPACT
                char_t* compact_string_base;
                void* compact_shared_parent;
                uint32_t* compact_page_marker;
        #endif
        };

        static const size_t xml_memory_page_size =
        #ifdef PUGIXML_MEMORY_PAGE_SIZE
                (PUGIXML_MEMORY_PAGE_SIZE)
        #else
                32768
        #endif
                - sizeof(xml_memory_page);

        struct xml_memory_string_header
        {
                uint16_t page_offset; // offset from page->data
                uint16_t full_size; // 0 if string occupies whole page
        };

        struct xml_allocator
        {
                xml_allocator(xml_memory_page* root): _root(root), _busy_size(root->busy_size)
                {
                #ifdef PUGIXML_COMPACT
                        _hash = 0;
                #endif
                }

                xml_memory_page* allocate_page(size_t data_size)
                {
                        size_t size = sizeof(xml_memory_page) + data_size;

                        // allocate block with some alignment, leaving memory for worst-case padding
                        void* memory = xml_memory::allocate(size);
                        if (!memory) return 0;

                        // prepare page structure
                        xml_memory_page* page = xml_memory_page::construct(memory);
                        assert(page);

                        page->allocator = _root->allocator;

                        return page;
                }

                static void deallocate_page(xml_memory_page* page)
                {
                        xml_memory::deallocate(page);
                }

                void* allocate_memory_oob(size_t size, xml_memory_page*& out_page);

                void* allocate_memory(size_t size, xml_memory_page*& out_page)
                {
                        if (PUGI__UNLIKELY(_busy_size + size > xml_memory_page_size))
                                return allocate_memory_oob(size, out_page);

                        void* buf = reinterpret_cast<char*>(_root) + sizeof(xml_memory_page) + _busy_size;

                        _busy_size += size;

                        out_page = _root;

                        return buf;
                }

        #ifdef PUGIXML_COMPACT
                void* allocate_object(size_t size, xml_memory_page*& out_page)
                {
                        void* result = allocate_memory(size + sizeof(uint32_t), out_page);
                        if (!result) return 0;

                        // adjust for marker
                        ptrdiff_t offset = static_cast<char*>(result) - reinterpret_cast<char*>(out_page->compact_page_marker);

                        if (PUGI__UNLIKELY(static_cast<uintptr_t>(offset) >= 256 * xml_memory_block_alignment))
                        {
                                // insert new marker
                                uint32_t* marker = static_cast<uint32_t*>(result);

                                *marker = static_cast<uint32_t>(reinterpret_cast<char*>(marker) - reinterpret_cast<char*>(out_page));
                                out_page->compact_page_marker = marker;

                                // since we don't reuse the page space until we reallocate it, we can just pretend that we freed the marker block
                                // this will make sure deallocate_memory correctly tracks the size
                                out_page->freed_size += sizeof(uint32_t);

                                return marker + 1;
                        }
                        else
                        {
                                // roll back uint32_t part
                                _busy_size -= sizeof(uint32_t);

                                return result;
                        }
                }
        #else
                void* allocate_object(size_t size, xml_memory_page*& out_page)
                {
                        return allocate_memory(size, out_page);
                }
        #endif

                void deallocate_memory(void* ptr, size_t size, xml_memory_page* page)
                {
                        if (page == _root) page->busy_size = _busy_size;

                        assert(ptr >= reinterpret_cast<char*>(page) + sizeof(xml_memory_page) && ptr < reinterpret_cast<char*>(page) + sizeof(xml_memory_page) + page->busy_size);
                        (void)!ptr;

                        page->freed_size += size;
                        assert(page->freed_size <= page->busy_size);

                        if (page->freed_size == page->busy_size)
                        {
                                if (page->next == 0)
                                {
                                        assert(_root == page);

                                        // top page freed, just reset sizes
                                        page->busy_size = 0;
                                        page->freed_size = 0;

                                #ifdef PUGIXML_COMPACT
                                        // reset compact state to maximize efficiency
                                        page->compact_string_base = 0;
                                        page->compact_shared_parent = 0;
                                        page->compact_page_marker = 0;
                                #endif

                                        _busy_size = 0;
                                }
                                else
                                {
                                        assert(_root != page);
                                        assert(page->prev);

                                        // remove from the list
                                        page->prev->next = page->next;
                                        page->next->prev = page->prev;

                                        // deallocate
                                        deallocate_page(page);
                                }
                        }
                }

                char_t* allocate_string(size_t length)
                {
                        static const size_t max_encoded_offset = (1 << 16) * xml_memory_block_alignment;

                        PUGI__STATIC_ASSERT(xml_memory_page_size <= max_encoded_offset);

                        // allocate memory for string and header block
                        size_t size = sizeof(xml_memory_string_header) + length * sizeof(char_t);

                        // round size up to block alignment boundary
                        size_t full_size = (size + (xml_memory_block_alignment - 1)) & ~(xml_memory_block_alignment - 1);

                        xml_memory_page* page;
                        xml_memory_string_header* header = static_cast<xml_memory_string_header*>(allocate_memory(full_size, page));

                        if (!header) return 0;

                        // setup header
                        ptrdiff_t page_offset = reinterpret_cast<char*>(header) - reinterpret_cast<char*>(page) - sizeof(xml_memory_page);

                        assert(page_offset % xml_memory_block_alignment == 0);
                        assert(page_offset >= 0 && static_cast<size_t>(page_offset) < max_encoded_offset);
                        header->page_offset = static_cast<uint16_t>(static_cast<size_t>(page_offset) / xml_memory_block_alignment);

                        // full_size == 0 for large strings that occupy the whole page
                        assert(full_size % xml_memory_block_alignment == 0);
                        assert(full_size < max_encoded_offset || (page->busy_size == full_size && page_offset == 0));
                        header->full_size = static_cast<uint16_t>(full_size < max_encoded_offset ? full_size / xml_memory_block_alignment : 0);

                        // round-trip through void* to avoid 'cast increases required alignment of target type' warning
                        // header is guaranteed a pointer-sized alignment, which should be enough for char_t
                        return static_cast<char_t*>(static_cast<void*>(header + 1));
                }

                void deallocate_string(char_t* string)
                {
                        // this function casts pointers through void* to avoid 'cast increases required alignment of target type' warnings
                        // we're guaranteed the proper (pointer-sized) alignment on the input string if it was allocated via allocate_string

                        // get header
                        xml_memory_string_header* header = static_cast<xml_memory_string_header*>(static_cast<void*>(string)) - 1;
                        assert(header);

                        // deallocate
                        size_t page_offset = sizeof(xml_memory_page) + header->page_offset * xml_memory_block_alignment;
                        xml_memory_page* page = reinterpret_cast<xml_memory_page*>(static_cast<void*>(reinterpret_cast<char*>(header) - page_offset));

                        // if full_size == 0 then this string occupies the whole page
                        size_t full_size = header->full_size == 0 ? page->busy_size : header->full_size * xml_memory_block_alignment;

                        deallocate_memory(header, full_size, page);
                }

                bool reserve()
                {
                #ifdef PUGIXML_COMPACT
                        return _hash->reserve();
                #else
                        return true;
                #endif
                }

                xml_memory_page* _root;
                size_t _busy_size;

        #ifdef PUGIXML_COMPACT
                compact_hash_table* _hash;
        #endif
        };

        PUGI__FN_NO_INLINE void* xml_allocator::allocate_memory_oob(size_t size, xml_memory_page*& out_page)
        {
                const size_t large_allocation_threshold = xml_memory_page_size / 4;

                xml_memory_page* page = allocate_page(size <= large_allocation_threshold ? xml_memory_page_size : size);
                out_page = page;

                if (!page) return 0;

                if (size <= large_allocation_threshold)
                {
                        _root->busy_size = _busy_size;

                        // insert page at the end of linked list
                        page->prev = _root;
                        _root->next = page;
                        _root = page;

                        _busy_size = size;
                }
                else
                {
                        // insert page before the end of linked list, so that it is deleted as soon as possible
                        // the last page is not deleted even if it's empty (see deallocate_memory)
                        assert(_root->prev);

                        page->prev = _root->prev;
                        page->next = _root;

                        _root->prev->next = page;
                        _root->prev = page;

                        page->busy_size = size;
                }

                return reinterpret_cast<char*>(page) + sizeof(xml_memory_page);
        }
PUGI__NS_END

#ifdef PUGIXML_COMPACT
PUGI__NS_BEGIN
        static const uintptr_t compact_alignment_log2 = 2;
        static const uintptr_t compact_alignment = 1 << compact_alignment_log2;

        class compact_header
        {
        public:
                compact_header(xml_memory_page* page, unsigned int flags)
                {
                        PUGI__STATIC_ASSERT(xml_memory_block_alignment == compact_alignment);

                        ptrdiff_t offset = (reinterpret_cast<char*>(this) - reinterpret_cast<char*>(page->compact_page_marker));
                        assert(offset % compact_alignment == 0 && static_cast<uintptr_t>(offset) < 256 * compact_alignment);

                        _page = static_cast<unsigned char>(offset >> compact_alignment_log2);
                        _flags = static_cast<unsigned char>(flags);
                }

                void operator&=(uintptr_t mod)
                {
                        _flags &= static_cast<unsigned char>(mod);
                }

                void operator|=(uintptr_t mod)
                {
                        _flags |= static_cast<unsigned char>(mod);
                }

                uintptr_t operator&(uintptr_t mod) const
                {
                        return _flags & mod;
                }

                xml_memory_page* get_page() const
                {
                        // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                        const char* page_marker = reinterpret_cast<const char*>(this) - (_page << compact_alignment_log2);
                        const char* page = page_marker - *reinterpret_cast<const uint32_t*>(static_cast<const void*>(page_marker));

                        return const_cast<xml_memory_page*>(reinterpret_cast<const xml_memory_page*>(static_cast<const void*>(page)));
                }

        private:
                unsigned char _page;
                unsigned char _flags;
        };

        PUGI__FN xml_memory_page* compact_get_page(const void* object, int header_offset)
        {
                const compact_header* header = reinterpret_cast<const compact_header*>(static_cast<const char*>(object) - header_offset);

                return header->get_page();
        }

        template <int header_offset, typename T> PUGI__FN_NO_INLINE T* compact_get_value(const void* object)
        {
                return static_cast<T*>(compact_get_page(object, header_offset)->allocator->_hash->find(object));
        }

        template <int header_offset, typename T> PUGI__FN_NO_INLINE void compact_set_value(const void* object, T* value)
        {
                compact_get_page(object, header_offset)->allocator->_hash->insert(object, value);
        }

        template <typename T, int header_offset, int start = -126> class compact_pointer
        {
        public:
                compact_pointer(): _data(0)
                {
                }

                void operator=(const compact_pointer& rhs)
                {
                        *this = rhs + 0;
                }

                void operator=(T* value)
                {
                        if (value)
                        {
                                // value is guaranteed to be compact-aligned; 'this' is not
                                // our decoding is based on 'this' aligned to compact alignment downwards (see operator T*)
                                // so for negative offsets (e.g. -3) we need to adjust the diff by compact_alignment - 1 to
                                // compensate for arithmetic shift rounding for negative values
                                ptrdiff_t diff = reinterpret_cast<char*>(value) - reinterpret_cast<char*>(this);
                                ptrdiff_t offset = ((diff + int(compact_alignment - 1)) >> compact_alignment_log2) - start;

                                if (static_cast<uintptr_t>(offset) <= 253)
                                        _data = static_cast<unsigned char>(offset + 1);
                                else
                                {
                                        compact_set_value<header_offset>(this, value);

                                        _data = 255;
                                }
                        }
                        else
                                _data = 0;
                }

                operator T*() const
                {
                        if (_data)
                        {
                                if (_data < 255)
                                {
                                        uintptr_t base = reinterpret_cast<uintptr_t>(this) & ~(compact_alignment - 1);

                                        return reinterpret_cast<T*>(base + (_data - 1 + start) * compact_alignment);
                                }
                                else
                                        return compact_get_value<header_offset, T>(this);
                        }
                        else
                                return 0;
                }

                T* operator->() const
                {
                        return *this;
                }

        private:
                unsigned char _data;
        };

        template <typename T, int header_offset> class compact_pointer_parent
        {
        public:
                compact_pointer_parent(): _data(0)
                {
                }

                void operator=(const compact_pointer_parent& rhs)
                {
                        *this = rhs + 0;
                }

                void operator=(T* value)
                {
                        if (value)
                        {
                                // value is guaranteed to be compact-aligned; 'this' is not
                                // our decoding is based on 'this' aligned to compact alignment downwards (see operator T*)
                                // so for negative offsets (e.g. -3) we need to adjust the diff by compact_alignment - 1 to
                                // compensate for arithmetic shift behavior for negative values
                                ptrdiff_t diff = reinterpret_cast<char*>(value) - reinterpret_cast<char*>(this);
                                ptrdiff_t offset = ((diff + int(compact_alignment - 1)) >> compact_alignment_log2) + 65533;

                                if (static_cast<uintptr_t>(offset) <= 65533)
                                {
                                        _data = static_cast<unsigned short>(offset + 1);
                                }
                                else
                                {
                                        xml_memory_page* page = compact_get_page(this, header_offset);

                                        if (PUGI__UNLIKELY(page->compact_shared_parent == 0))
                                                page->compact_shared_parent = value;

                                        if (page->compact_shared_parent == value)
                                        {
                                                _data = 65534;
                                        }
                                        else
                                        {
                                                compact_set_value<header_offset>(this, value);

                                                _data = 65535;
                                        }
                                }
                        }
                        else
                        {
                                _data = 0;
                        }
                }

                operator T*() const
                {
                        if (_data)
                        {
                                if (_data < 65534)
                                {
                                        uintptr_t base = reinterpret_cast<uintptr_t>(this) & ~(compact_alignment - 1);

                                        return reinterpret_cast<T*>(base + (_data - 1 - 65533) * compact_alignment);
                                }
                                else if (_data == 65534)
                                        return static_cast<T*>(compact_get_page(this, header_offset)->compact_shared_parent);
                                else
                                        return compact_get_value<header_offset, T>(this);
                        }
                        else
                                return 0;
                }

                T* operator->() const
                {
                        return *this;
                }

        private:
                uint16_t _data;
        };

        template <int header_offset, int base_offset> class compact_string
        {
        public:
                compact_string(): _data(0)
                {
                }

                void operator=(const compact_string& rhs)
                {
                        *this = rhs + 0;
                }

                void operator=(char_t* value)
                {
                        if (value)
                        {
                                xml_memory_page* page = compact_get_page(this, header_offset);

                                if (PUGI__UNLIKELY(page->compact_string_base == 0))
                                        page->compact_string_base = value;

                                ptrdiff_t offset = value - page->compact_string_base;

                                if (static_cast<uintptr_t>(offset) < (65535 << 7))
                                {
                                        // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                                        uint16_t* base = reinterpret_cast<uint16_t*>(static_cast<void*>(reinterpret_cast<char*>(this) - base_offset));

                                        if (*base == 0)
                                        {
                                                *base = static_cast<uint16_t>((offset >> 7) + 1);
                                                _data = static_cast<unsigned char>((offset & 127) + 1);
                                        }
                                        else
                                        {
                                                ptrdiff_t remainder = offset - ((*base - 1) << 7);

                                                if (static_cast<uintptr_t>(remainder) <= 253)
                                                {
                                                        _data = static_cast<unsigned char>(remainder + 1);
                                                }
                                                else
                                                {
                                                        compact_set_value<header_offset>(this, value);

                                                        _data = 255;
                                                }
                                        }
                                }
                                else
                                {
                                        compact_set_value<header_offset>(this, value);

                                        _data = 255;
                                }
                        }
                        else
                        {
                                _data = 0;
                        }
                }

                operator char_t*() const
                {
                        if (_data)
                        {
                                if (_data < 255)
                                {
                                        xml_memory_page* page = compact_get_page(this, header_offset);

                                        // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                                        const uint16_t* base = reinterpret_cast<const uint16_t*>(static_cast<const void*>(reinterpret_cast<const char*>(this) - base_offset));
                                        assert(*base);

                                        ptrdiff_t offset = ((*base - 1) << 7) + (_data - 1);

                                        return page->compact_string_base + offset;
                                }
                                else
                                {
                                        return compact_get_value<header_offset, char_t>(this);
                                }
                        }
                        else
                                return 0;
                }

        private:
                unsigned char _data;
        };
PUGI__NS_END
#endif

#ifdef PUGIXML_COMPACT
namespace pugi
{
        struct xml_attribute_struct
        {
                xml_attribute_struct(impl::xml_memory_page* page): header(page, 0), namevalue_base(0)
                {
                        PUGI__STATIC_ASSERT(sizeof(xml_attribute_struct) == 8);
                }

                impl::compact_header header;

                uint16_t namevalue_base;

                impl::compact_string<4, 2> name;
                impl::compact_string<5, 3> value;

                impl::compact_pointer<xml_attribute_struct, 6> prev_attribute_c;
                impl::compact_pointer<xml_attribute_struct, 7, 0> next_attribute;
        };

        struct xml_node_struct
        {
                xml_node_struct(impl::xml_memory_page* page, xml_node_type type): header(page, type), namevalue_base(0)
                {
                        PUGI__STATIC_ASSERT(sizeof(xml_node_struct) == 12);
                }

                impl::compact_header header;

                uint16_t namevalue_base;

                impl::compact_string<4, 2> name;
                impl::compact_string<5, 3> value;

                impl::compact_pointer_parent<xml_node_struct, 6> parent;

                impl::compact_pointer<xml_node_struct, 8, 0> first_child;

                impl::compact_pointer<xml_node_struct,  9>    prev_sibling_c;
                impl::compact_pointer<xml_node_struct, 10, 0> next_sibling;

                impl::compact_pointer<xml_attribute_struct, 11, 0> first_attribute;
        };
}
#else
namespace pugi
{
        struct xml_attribute_struct
        {
                xml_attribute_struct(impl::xml_memory_page* page): name(0), value(0), prev_attribute_c(0), next_attribute(0)
                {
                        header = PUGI__GETHEADER_IMPL(this, page, 0);
                }

                uintptr_t header;

                char_t* name;
                char_t* value;

                xml_attribute_struct* prev_attribute_c;
                xml_attribute_struct* next_attribute;
        };

        struct xml_node_struct
        {
                xml_node_struct(impl::xml_memory_page* page, xml_node_type type): name(0), value(0), parent(0), first_child(0), prev_sibling_c(0), next_sibling(0), first_attribute(0)
                {
                        header = PUGI__GETHEADER_IMPL(this, page, type);
                }

                uintptr_t header;

                char_t* name;
                char_t* value;

                xml_node_struct* parent;

                xml_node_struct* first_child;

                xml_node_struct* prev_sibling_c;
                xml_node_struct* next_sibling;

                xml_attribute_struct* first_attribute;
        };
}
#endif

PUGI__NS_BEGIN
        struct xml_extra_buffer
        {
                char_t* buffer;
                xml_extra_buffer* next;
        };

        struct xml_document_struct: public xml_node_struct, public xml_allocator
        {
                xml_document_struct(xml_memory_page* page): xml_node_struct(page, node_document), xml_allocator(page), buffer(0), extra_buffers(0)
                {
                }

                const char_t* buffer;

                xml_extra_buffer* extra_buffers;

        #ifdef PUGIXML_COMPACT
                compact_hash_table hash;
        #endif
        };

        template <typename Object> inline xml_allocator& get_allocator(const Object* object)
        {
                assert(object);

                return *PUGI__GETPAGE(object)->allocator;
        }

        template <typename Object> inline xml_document_struct& get_document(const Object* object)
        {
                assert(object);

                return *static_cast<xml_document_struct*>(PUGI__GETPAGE(object)->allocator);
        }
PUGI__NS_END

// Low-level DOM operations
PUGI__NS_BEGIN
        inline xml_attribute_struct* allocate_attribute(xml_allocator& alloc)
        {
                xml_memory_page* page;
                void* memory = alloc.allocate_object(sizeof(xml_attribute_struct), page);
                if (!memory) return 0;

                return new (memory) xml_attribute_struct(page);
        }

        inline xml_node_struct* allocate_node(xml_allocator& alloc, xml_node_type type)
        {
                xml_memory_page* page;
                void* memory = alloc.allocate_object(sizeof(xml_node_struct), page);
                if (!memory) return 0;

                return new (memory) xml_node_struct(page, type);
        }

        inline void destroy_attribute(xml_attribute_struct* a, xml_allocator& alloc)
        {
                if (a->header & impl::xml_memory_page_name_allocated_mask)
                        alloc.deallocate_string(a->name);

                if (a->header & impl::xml_memory_page_value_allocated_mask)
                        alloc.deallocate_string(a->value);

                alloc.deallocate_memory(a, sizeof(xml_attribute_struct), PUGI__GETPAGE(a));
        }

        inline void destroy_node(xml_node_struct* n, xml_allocator& alloc)
        {
                if (n->header & impl::xml_memory_page_name_allocated_mask)
                        alloc.deallocate_string(n->name);

                if (n->header & impl::xml_memory_page_value_allocated_mask)
                        alloc.deallocate_string(n->value);

                for (xml_attribute_struct* attr = n->first_attribute; attr; )
                {
                        xml_attribute_struct* next = attr->next_attribute;

                        destroy_attribute(attr, alloc);

                        attr = next;
                }

                for (xml_node_struct* child = n->first_child; child; )
                {
                        xml_node_struct* next = child->next_sibling;

                        destroy_node(child, alloc);

                        child = next;
                }

                alloc.deallocate_memory(n, sizeof(xml_node_struct), PUGI__GETPAGE(n));
        }

        inline void append_node(xml_node_struct* child, xml_node_struct* node)
        {
                child->parent = node;

                xml_node_struct* head = node->first_child;

                if (head)
                {
                        xml_node_struct* tail = head->prev_sibling_c;

                        tail->next_sibling = child;
                        child->prev_sibling_c = tail;
                        head->prev_sibling_c = child;
                }
                else
                {
                        node->first_child = child;
                        child->prev_sibling_c = child;
                }
        }

        inline void prepend_node(xml_node_struct* child, xml_node_struct* node)
        {
                child->parent = node;

                xml_node_struct* head = node->first_child;

                if (head)
                {
                        child->prev_sibling_c = head->prev_sibling_c;
                        head->prev_sibling_c = child;
                }
                else
                        child->prev_sibling_c = child;

                child->next_sibling = head;
                node->first_child = child;
        }

        inline void insert_node_after(xml_node_struct* child, xml_node_struct* node)
        {
                xml_node_struct* parent = node->parent;

                child->parent = parent;

                if (node->next_sibling)
                        node->next_sibling->prev_sibling_c = child;
                else
                        parent->first_child->prev_sibling_c = child;

                child->next_sibling = node->next_sibling;
                child->prev_sibling_c = node;

                node->next_sibling = child;
        }

        inline void insert_node_before(xml_node_struct* child, xml_node_struct* node)
        {
                xml_node_struct* parent = node->parent;

                child->parent = parent;

                if (node->prev_sibling_c->next_sibling)
                        node->prev_sibling_c->next_sibling = child;
                else
                        parent->first_child = child;

                child->prev_sibling_c = node->prev_sibling_c;
                child->next_sibling = node;

                node->prev_sibling_c = child;
        }

        inline void remove_node(xml_node_struct* node)
        {
                xml_node_struct* parent = node->parent;

                if (node->next_sibling)
                        node->next_sibling->prev_sibling_c = node->prev_sibling_c;
                else
                        parent->first_child->prev_sibling_c = node->prev_sibling_c;

                if (node->prev_sibling_c->next_sibling)
                        node->prev_sibling_c->next_sibling = node->next_sibling;
                else
                        parent->first_child = node->next_sibling;

                node->parent = 0;
                node->prev_sibling_c = 0;
                node->next_sibling = 0;
        }

        inline void append_attribute(xml_attribute_struct* attr, xml_node_struct* node)
        {
                xml_attribute_struct* head = node->first_attribute;

                if (head)
                {
                        xml_attribute_struct* tail = head->prev_attribute_c;

                        tail->next_attribute = attr;
                        attr->prev_attribute_c = tail;
                        head->prev_attribute_c = attr;
                }
                else
                {
                        node->first_attribute = attr;
                        attr->prev_attribute_c = attr;
                }
        }

        inline void prepend_attribute(xml_attribute_struct* attr, xml_node_struct* node)
        {
                xml_attribute_struct* head = node->first_attribute;

                if (head)
                {
                        attr->prev_attribute_c = head->prev_attribute_c;
                        head->prev_attribute_c = attr;
                }
                else
                        attr->prev_attribute_c = attr;

                attr->next_attribute = head;
                node->first_attribute = attr;
        }

        inline void insert_attribute_after(xml_attribute_struct* attr, xml_attribute_struct* place, xml_node_struct* node)
        {
                if (place->next_attribute)
                        place->next_attribute->prev_attribute_c = attr;
                else
                        node->first_attribute->prev_attribute_c = attr;

                attr->next_attribute = place->next_attribute;
                attr->prev_attribute_c = place;
                place->next_attribute = attr;
        }

        inline void insert_attribute_before(xml_attribute_struct* attr, xml_attribute_struct* place, xml_node_struct* node)
        {
                if (place->prev_attribute_c->next_attribute)
                        place->prev_attribute_c->next_attribute = attr;
                else
                        node->first_attribute = attr;

                attr->prev_attribute_c = place->prev_attribute_c;
                attr->next_attribute = place;
                place->prev_attribute_c = attr;
        }

        inline void remove_attribute(xml_attribute_struct* attr, xml_node_struct* node)
        {
                if (attr->next_attribute)
                        attr->next_attribute->prev_attribute_c = attr->prev_attribute_c;
                else
                        node->first_attribute->prev_attribute_c = attr->prev_attribute_c;

                if (attr->prev_attribute_c->next_attribute)
                        attr->prev_attribute_c->next_attribute = attr->next_attribute;
                else
                        node->first_attribute = attr->next_attribute;

                attr->prev_attribute_c = 0;
                attr->next_attribute = 0;
        }

        PUGI__FN_NO_INLINE xml_node_struct* append_new_node(xml_node_struct* node, xml_allocator& alloc, xml_node_type type = node_element)
        {
                if (!alloc.reserve()) return 0;

                xml_node_struct* child = allocate_node(alloc, type);
                if (!child) return 0;

                append_node(child, node);

                return child;
        }

        PUGI__FN_NO_INLINE xml_attribute_struct* append_new_attribute(xml_node_struct* node, xml_allocator& alloc)
        {
                if (!alloc.reserve()) return 0;

                xml_attribute_struct* attr = allocate_attribute(alloc);
                if (!attr) return 0;

                append_attribute(attr, node);

                return attr;
        }
PUGI__NS_END

// Helper classes for code generation
PUGI__NS_BEGIN
        struct opt_false
        {
                enum { value = 0 };
        };

        struct opt_true
        {
                enum { value = 1 };
        };
PUGI__NS_END

// Unicode utilities
PUGI__NS_BEGIN
        inline uint16_t endian_swap(uint16_t value)
        {
                return static_cast<uint16_t>(((value & 0xff) << 8) | (value >> 8));
        }

        inline uint32_t endian_swap(uint32_t value)
        {
                return ((value & 0xff) << 24) | ((value & 0xff00) << 8) | ((value & 0xff0000) >> 8) | (value >> 24);
        }

        struct utf8_counter
        {
                typedef size_t value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        // U+0000..U+007F
                        if (ch < 0x80) return result + 1;
                        // U+0080..U+07FF
                        else if (ch < 0x800) return result + 2;
                        // U+0800..U+FFFF
                        else return result + 3;
                }

                static value_type high(value_type result, uint32_t)
                {
                        // U+10000..U+10FFFF
                        return result + 4;
                }
        };

        struct utf8_writer
        {
                typedef uint8_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        // U+0000..U+007F
                        if (ch < 0x80)
                        {
                                *result = static_cast<uint8_t>(ch);
                                return result + 1;
                        }
                        // U+0080..U+07FF
                        else if (ch < 0x800)
                        {
                                result[0] = static_cast<uint8_t>(0xC0 | (ch >> 6));
                                result[1] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
                                return result + 2;
                        }
                        // U+0800..U+FFFF
                        else
                        {
                                result[0] = static_cast<uint8_t>(0xE0 | (ch >> 12));
                                result[1] = static_cast<uint8_t>(0x80 | ((ch >> 6) & 0x3F));
                                result[2] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
                                return result + 3;
                        }
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        // U+10000..U+10FFFF
                        result[0] = static_cast<uint8_t>(0xF0 | (ch >> 18));
                        result[1] = static_cast<uint8_t>(0x80 | ((ch >> 12) & 0x3F));
                        result[2] = static_cast<uint8_t>(0x80 | ((ch >> 6) & 0x3F));
                        result[3] = static_cast<uint8_t>(0x80 | (ch & 0x3F));
                        return result + 4;
                }

                static value_type any(value_type result, uint32_t ch)
                {
                        return (ch < 0x10000) ? low(result, ch) : high(result, ch);
                }
        };

        struct utf16_counter
        {
                typedef size_t value_type;

                static value_type low(value_type result, uint32_t)
                {
                        return result + 1;
                }

                static value_type high(value_type result, uint32_t)
                {
                        return result + 2;
                }
        };

        struct utf16_writer
        {
                typedef uint16_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        *result = static_cast<uint16_t>(ch);

                        return result + 1;
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        uint32_t msh = static_cast<uint32_t>(ch - 0x10000) >> 10;
                        uint32_t lsh = static_cast<uint32_t>(ch - 0x10000) & 0x3ff;

                        result[0] = static_cast<uint16_t>(0xD800 + msh);
                        result[1] = static_cast<uint16_t>(0xDC00 + lsh);

                        return result + 2;
                }

                static value_type any(value_type result, uint32_t ch)
                {
                        return (ch < 0x10000) ? low(result, ch) : high(result, ch);
                }
        };

        struct utf32_counter
        {
                typedef size_t value_type;

                static value_type low(value_type result, uint32_t)
                {
                        return result + 1;
                }

                static value_type high(value_type result, uint32_t)
                {
                        return result + 1;
                }
        };

        struct utf32_writer
        {
                typedef uint32_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        *result = ch;

                        return result + 1;
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        *result = ch;

                        return result + 1;
                }

                static value_type any(value_type result, uint32_t ch)
                {
                        *result = ch;

                        return result + 1;
                }
        };

        struct latin1_writer
        {
                typedef uint8_t* value_type;

                static value_type low(value_type result, uint32_t ch)
                {
                        *result = static_cast<uint8_t>(ch > 255 ? '?' : ch);

                        return result + 1;
                }

                static value_type high(value_type result, uint32_t ch)
                {
                        (void)ch;

                        *result = '?';

                        return result + 1;
                }
        };

        struct utf8_decoder
        {
                typedef uint8_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint8_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        const uint8_t utf8_byte_mask = 0x3f;

                        while (size)
                        {
                                uint8_t lead = *data;

                                // 0xxxxxxx -> U+0000..U+007F
                                if (lead < 0x80)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;

                                        // process aligned single-byte (ascii) blocks
                                        if ((reinterpret_cast<uintptr_t>(data) & 3) == 0)
                                        {
                                                // round-trip through void* to silence 'cast increases required alignment of target type' warnings
                                                while (size >= 4 && (*static_cast<const uint32_t*>(static_cast<const void*>(data)) & 0x80808080) == 0)
                                                {
                                                        result = Traits::low(result, data[0]);
                                                        result = Traits::low(result, data[1]);
                                                        result = Traits::low(result, data[2]);
                                                        result = Traits::low(result, data[3]);
                                                        data += 4;
                                                        size -= 4;
                                                }
                                        }
                                }
                                // 110xxxxx -> U+0080..U+07FF
                                else if (static_cast<unsigned int>(lead - 0xC0) < 0x20 && size >= 2 && (data[1] & 0xc0) == 0x80)
                                {
                                        result = Traits::low(result, ((lead & ~0xC0) << 6) | (data[1] & utf8_byte_mask));
                                        data += 2;
                                        size -= 2;
                                }
                                // 1110xxxx -> U+0800-U+FFFF
                                else if (static_cast<unsigned int>(lead - 0xE0) < 0x10 && size >= 3 && (data[1] & 0xc0) == 0x80 && (data[2] & 0xc0) == 0x80)
                                {
                                        result = Traits::low(result, ((lead & ~0xE0) << 12) | ((data[1] & utf8_byte_mask) << 6) | (data[2] & utf8_byte_mask));
                                        data += 3;
                                        size -= 3;
                                }
                                // 11110xxx -> U+10000..U+10FFFF
                                else if (static_cast<unsigned int>(lead - 0xF0) < 0x08 && size >= 4 && (data[1] & 0xc0) == 0x80 && (data[2] & 0xc0) == 0x80 && (data[3] & 0xc0) == 0x80)
                                {
                                        result = Traits::high(result, ((lead & ~0xF0) << 18) | ((data[1] & utf8_byte_mask) << 12) | ((data[2] & utf8_byte_mask) << 6) | (data[3] & utf8_byte_mask));
                                        data += 4;
                                        size -= 4;
                                }
                                // 10xxxxxx or 11111xxx -> invalid
                                else
                                {
                                        data += 1;
                                        size -= 1;
                                }
                        }

                        return result;
                }
        };

        template <typename opt_swap> struct utf16_decoder
        {
                typedef uint16_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint16_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        while (size)
                        {
                                uint16_t lead = opt_swap::value ? endian_swap(*data) : *data;

                                // U+0000..U+D7FF
                                if (lead < 0xD800)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                                // U+E000..U+FFFF
                                else if (static_cast<unsigned int>(lead - 0xE000) < 0x2000)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                                // surrogate pair lead
                                else if (static_cast<unsigned int>(lead - 0xD800) < 0x400 && size >= 2)
                                {
                                        uint16_t next = opt_swap::value ? endian_swap(data[1]) : data[1];

                                        if (static_cast<unsigned int>(next - 0xDC00) < 0x400)
                                        {
                                                result = Traits::high(result, 0x10000 + ((lead & 0x3ff) << 10) + (next & 0x3ff));
                                                data += 2;
                                                size -= 2;
                                        }
                                        else
                                        {
                                                data += 1;
                                                size -= 1;
                                        }
                                }
                                else
                                {
                                        data += 1;
                                        size -= 1;
                                }
                        }

                        return result;
                }
        };

        template <typename opt_swap> struct utf32_decoder
        {
                typedef uint32_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint32_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        while (size)
                        {
                                uint32_t lead = opt_swap::value ? endian_swap(*data) : *data;

                                // U+0000..U+FFFF
                                if (lead < 0x10000)
                                {
                                        result = Traits::low(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                                // U+10000..U+10FFFF
                                else
                                {
                                        result = Traits::high(result, lead);
                                        data += 1;
                                        size -= 1;
                                }
                        }

                        return result;
                }
        };

        struct latin1_decoder
        {
                typedef uint8_t type;

                template <typename Traits> static inline typename Traits::value_type process(const uint8_t* data, size_t size, typename Traits::value_type result, Traits)
                {
                        while (size)
                        {
                                result = Traits::low(result, *data);
                                data += 1;
                                size -= 1;
                        }

                        return result;
                }
        };

        template <size_t size> struct wchar_selector;

        template <> struct wchar_selector<2>
        {
                typedef uint16_t type;
                typedef utf16_counter counter;
                typedef utf16_writer writer;
                typedef utf16_decoder<opt_false> decoder;
        };

        template <> struct wchar_selector<4>
        {
                typedef uint32_t type;
                typedef utf32_counter counter;
                typedef utf32_writer writer;
                typedef utf32_decoder<opt_false> decoder;
        };

        typedef wchar_selector<sizeof(wchar_t)>::counter wchar_counter;
        typedef wchar_selector<sizeof(wchar_t)>::writer wchar_writer;

        struct wchar_decoder
        {
                typedef wchar_t type;

                template <typename Traits> static inline typename Traits::value_type process(const wchar_t* data, size_t size, typename Traits::value_type result, Traits traits)
                {
                        typedef wchar_selector<sizeof(wchar_t)>::decoder decoder;

                        return decoder::process(reinterpret_cast<const typename decoder::type*>(data), size, result, traits);
                }
        };

#ifdef PUGIXML_WCHAR_MODE
        PUGI__FN void convert_wchar_endian_swap(wchar_t* result, const wchar_t* data, size_t length)
        {
                for (size_t i = 0; i < length; ++i)
                        result[i] = static_cast<wchar_t>(endian_swap(static_cast<wchar_selector<sizeof(wchar_t)>::type>(data[i])));
        }
#endif
PUGI__NS_END

PUGI__NS_BEGIN
        enum chartype_t
        {
                ct_parse_pcdata = 1,    // \0, &, \r, <
                ct_parse_attr = 2,              // \0, &, \r, ', "
                ct_parse_attr_ws = 4,   // \0, &, \r, ', ", \n, tab
                ct_space = 8,                   // \r, \n, space, tab
                ct_parse_cdata = 16,    // \0, ], >, \r
                ct_parse_comment = 32,  // \0, -, >, \r
                ct_symbol = 64,                 // Any symbol > 127, a-z, A-Z, 0-9, _, :, -, .
                ct_start_symbol = 128   // Any symbol > 127, a-z, A-Z, _, :
        };

        static const unsigned char chartype_table[256] =
        {
                55,  0,   0,   0,   0,   0,   0,   0,      0,   12,  12,  0,   0,   63,  0,   0,   // 0-15
                0,   0,   0,   0,   0,   0,   0,   0,      0,   0,   0,   0,   0,   0,   0,   0,   // 16-31
                8,   0,   6,   0,   0,   0,   7,   6,      0,   0,   0,   0,   0,   96,  64,  0,   // 32-47
                64,  64,  64,  64,  64,  64,  64,  64,     64,  64,  192, 0,   1,   0,   48,  0,   // 48-63
                0,   192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192, // 64-79
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 0,   0,   16,  0,   192, // 80-95
                0,   192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192, // 96-111
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 0, 0, 0, 0, 0,           // 112-127

                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192, // 128+
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192,
                192, 192, 192, 192, 192, 192, 192, 192,    192, 192, 192, 192, 192, 192, 192, 192
        };

        enum chartypex_t
        {
                ctx_special_pcdata = 1,   // Any symbol >= 0 and < 32 (except \t, \r, \n), &, <, >
                ctx_special_attr = 2,     // Any symbol >= 0 and < 32 (except \t), &, <, >, "
                ctx_start_symbol = 4,     // Any symbol > 127, a-z, A-Z, _
                ctx_digit = 8,                    // 0-9
                ctx_symbol = 16                   // Any symbol > 127, a-z, A-Z, 0-9, _, -, .
        };

        static const unsigned char chartypex_table[256] =
        {
                3,  3,  3,  3,  3,  3,  3,  3,     3,  0,  2,  3,  3,  2,  3,  3,     // 0-15
                3,  3,  3,  3,  3,  3,  3,  3,     3,  3,  3,  3,  3,  3,  3,  3,     // 16-31
                0,  0,  2,  0,  0,  0,  3,  0,     0,  0,  0,  0,  0, 16, 16,  0,     // 32-47
                24, 24, 24, 24, 24, 24, 24, 24,    24, 24, 0,  0,  3,  0,  3,  0,     // 48-63

                0,  20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,    // 64-79
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 0,  0,  0,  0,  20,    // 80-95
                0,  20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,    // 96-111
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 0,  0,  0,  0,  0,     // 112-127

                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,    // 128+
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20,
                20, 20, 20, 20, 20, 20, 20, 20,    20, 20, 20, 20, 20, 20, 20, 20
        };

#ifdef PUGIXML_WCHAR_MODE
        #define PUGI__IS_CHARTYPE_IMPL(c, ct, table) ((static_cast<unsigned int>(c) < 128 ? table[static_cast<unsigned int>(c)] : table[128]) & (ct))
#else
        #define PUGI__IS_CHARTYPE_IMPL(c, ct, table) (table[static_cast<unsigned char>(c)] & (ct))
#endif

        #define PUGI__IS_CHARTYPE(c, ct) PUGI__IS_CHARTYPE_IMPL(c, ct, chartype_table)
        #define PUGI__IS_CHARTYPEX(c, ct) PUGI__IS_CHARTYPE_IMPL(c, ct, chartypex_table)

        PUGI__FN bool is_little_endian()
        {
                unsigned int ui = 1;

                return *reinterpret_cast<unsigned char*>(&ui) == 1;
        }

        PUGI__FN xml_encoding get_wchar_encoding()
        {
                PUGI__STATIC_ASSERT(sizeof(wchar_t) == 2 || sizeof(wchar_t) == 4);

                if (sizeof(wchar_t) == 2)
                        return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;
                else
                        return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;
        }

        PUGI__FN bool parse_declaration_encoding(const uint8_t* data, size_t size, const uint8_t*& out_encoding, size_t& out_length)
        {
        #define PUGI__SCANCHAR(ch) { if (offset >= size || data[offset] != ch) return false; offset++; }
        #define PUGI__SCANCHARTYPE(ct) { while (offset < size && PUGI__IS_CHARTYPE(data[offset], ct)) offset++; }

                // check if we have a non-empty XML declaration
                if (size < 6 || !((data[0] == '<') & (data[1] == '?') & (data[2] == 'x') & (data[3] == 'm') & (data[4] == 'l') && PUGI__IS_CHARTYPE(data[5], ct_space)))
                        return false;

                // scan XML declaration until the encoding field
                for (size_t i = 6; i + 1 < size; ++i)
                {
                        // declaration can not contain ? in quoted values
                        if (data[i] == '?')
                                return false;

                        if (data[i] == 'e' && data[i + 1] == 'n')
                        {
                                size_t offset = i;

                                // encoding follows the version field which can't contain 'en' so this has to be the encoding if XML is well formed
                                PUGI__SCANCHAR('e'); PUGI__SCANCHAR('n'); PUGI__SCANCHAR('c'); PUGI__SCANCHAR('o');
                                PUGI__SCANCHAR('d'); PUGI__SCANCHAR('i'); PUGI__SCANCHAR('n'); PUGI__SCANCHAR('g');

                                // S? = S?
                                PUGI__SCANCHARTYPE(ct_space);
                                PUGI__SCANCHAR('=');
                                PUGI__SCANCHARTYPE(ct_space);

                                // the only two valid delimiters are ' and "
                                uint8_t delimiter = (offset < size && data[offset] == '"') ? '"' : '\'';

                                PUGI__SCANCHAR(delimiter);

                                size_t start = offset;

                                out_encoding = data + offset;

                                PUGI__SCANCHARTYPE(ct_symbol);

                                out_length = offset - start;

                                PUGI__SCANCHAR(delimiter);

                                return true;
                        }
                }

                return false;

        #undef PUGI__SCANCHAR
        #undef PUGI__SCANCHARTYPE
        }

        PUGI__FN xml_encoding guess_buffer_encoding(const uint8_t* data, size_t size)
        {
                // skip encoding autodetection if input buffer is too small
                if (size < 4) return encoding_utf8;

                uint8_t d0 = data[0], d1 = data[1], d2 = data[2], d3 = data[3];

                // look for BOM in first few bytes
                if (d0 == 0 && d1 == 0 && d2 == 0xfe && d3 == 0xff) return encoding_utf32_be;
                if (d0 == 0xff && d1 == 0xfe && d2 == 0 && d3 == 0) return encoding_utf32_le;
                if (d0 == 0xfe && d1 == 0xff) return encoding_utf16_be;
                if (d0 == 0xff && d1 == 0xfe) return encoding_utf16_le;
                if (d0 == 0xef && d1 == 0xbb && d2 == 0xbf) return encoding_utf8;

                // look for <, <? or <?xm in various encodings
                if (d0 == 0 && d1 == 0 && d2 == 0 && d3 == 0x3c) return encoding_utf32_be;
                if (d0 == 0x3c && d1 == 0 && d2 == 0 && d3 == 0) return encoding_utf32_le;
                if (d0 == 0 && d1 == 0x3c && d2 == 0 && d3 == 0x3f) return encoding_utf16_be;
                if (d0 == 0x3c && d1 == 0 && d2 == 0x3f && d3 == 0) return encoding_utf16_le;

                // look for utf16 < followed by node name (this may fail, but is better than utf8 since it's zero terminated so early)
                if (d0 == 0 && d1 == 0x3c) return encoding_utf16_be;
                if (d0 == 0x3c && d1 == 0) return encoding_utf16_le;

                // no known BOM detected; parse declaration
                const uint8_t* enc = 0;
                size_t enc_length = 0;

                if (d0 == 0x3c && d1 == 0x3f && d2 == 0x78 && d3 == 0x6d && parse_declaration_encoding(data, size, enc, enc_length))
                {
                        // iso-8859-1 (case-insensitive)
                        if (enc_length == 10
                                && (enc[0] | ' ') == 'i' && (enc[1] | ' ') == 's' && (enc[2] | ' ') == 'o'
                                && enc[3] == '-' && enc[4] == '8' && enc[5] == '8' && enc[6] == '5' && enc[7] == '9'
                                && enc[8] == '-' && enc[9] == '1')
                                return encoding_latin1;

                        // latin1 (case-insensitive)
                        if (enc_length == 6
                                && (enc[0] | ' ') == 'l' && (enc[1] | ' ') == 'a' && (enc[2] | ' ') == 't'
                                && (enc[3] | ' ') == 'i' && (enc[4] | ' ') == 'n'
                                && enc[5] == '1')
                                return encoding_latin1;
                }

                return encoding_utf8;
        }

        PUGI__FN xml_encoding get_buffer_encoding(xml_encoding encoding, const void* contents, size_t size)
        {
                // replace wchar encoding with utf implementation
                if (encoding == encoding_wchar) return get_wchar_encoding();

                // replace utf16 encoding with utf16 with specific endianness
                if (encoding == encoding_utf16) return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                // replace utf32 encoding with utf32 with specific endianness
                if (encoding == encoding_utf32) return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                // only do autodetection if no explicit encoding is requested
                if (encoding != encoding_auto) return encoding;

                // try to guess encoding (based on XML specification, Appendix F.1)
                const uint8_t* data = static_cast<const uint8_t*>(contents);

                return guess_buffer_encoding(data, size);
        }

        PUGI__FN bool get_mutable_buffer(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
        {
                size_t length = size / sizeof(char_t);

                if (is_mutable)
                {
                        out_buffer = static_cast<char_t*>(const_cast<void*>(contents));
                        out_length = length;
                }
                else
                {
                        char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                        if (!buffer) return false;

                        if (contents)
                                memcpy(buffer, contents, length * sizeof(char_t));
                        else
                                assert(length == 0);

                        buffer[length] = 0;

                        out_buffer = buffer;
                        out_length = length + 1;
                }

                return true;
        }

#ifdef PUGIXML_WCHAR_MODE
        PUGI__FN bool need_endian_swap_utf(xml_encoding le, xml_encoding re)
        {
                return (le == encoding_utf16_be && re == encoding_utf16_le) || (le == encoding_utf16_le && re == encoding_utf16_be) ||
                           (le == encoding_utf32_be && re == encoding_utf32_le) || (le == encoding_utf32_le && re == encoding_utf32_be);
        }

        PUGI__FN bool convert_buffer_endian_swap(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
        {
                const char_t* data = static_cast<const char_t*>(contents);
                size_t length = size / sizeof(char_t);

                if (is_mutable)
                {
                        char_t* buffer = const_cast<char_t*>(data);

                        convert_wchar_endian_swap(buffer, data, length);

                        out_buffer = buffer;
                        out_length = length;
                }
                else
                {
                        char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                        if (!buffer) return false;

                        convert_wchar_endian_swap(buffer, data, length);
                        buffer[length] = 0;

                        out_buffer = buffer;
                        out_length = length + 1;
                }

                return true;
        }

        template <typename D> PUGI__FN bool convert_buffer_generic(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, D)
        {
                const typename D::type* data = static_cast<const typename D::type*>(contents);
                size_t data_length = size / sizeof(typename D::type);

                // first pass: get length in wchar_t units
                size_t length = D::process(data, data_length, 0, wchar_counter());

                // allocate buffer of suitable length
                char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                if (!buffer) return false;

                // second pass: convert utf16 input to wchar_t
                wchar_writer::value_type obegin = reinterpret_cast<wchar_writer::value_type>(buffer);
                wchar_writer::value_type oend = D::process(data, data_length, obegin, wchar_writer());

                assert(oend == obegin + length);
                *oend = 0;

                out_buffer = buffer;
                out_length = length + 1;

                return true;
        }

        PUGI__FN bool convert_buffer(char_t*& out_buffer, size_t& out_length, xml_encoding encoding, const void* contents, size_t size, bool is_mutable)
        {
                // get native encoding
                xml_encoding wchar_encoding = get_wchar_encoding();

                // fast path: no conversion required
                if (encoding == wchar_encoding)
                        return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

                // only endian-swapping is required
                if (need_endian_swap_utf(encoding, wchar_encoding))
                        return convert_buffer_endian_swap(out_buffer, out_length, contents, size, is_mutable);

                // source encoding is utf8
                if (encoding == encoding_utf8)
                        return convert_buffer_generic(out_buffer, out_length, contents, size, utf8_decoder());

                // source encoding is utf16
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_true>());
                }

                // source encoding is utf32
                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_true>());
                }

                // source encoding is latin1
                if (encoding == encoding_latin1)
                        return convert_buffer_generic(out_buffer, out_length, contents, size, latin1_decoder());

                assert(false && "Invalid encoding"); // unreachable
                return false;
        }
#else
        template <typename D> PUGI__FN bool convert_buffer_generic(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, D)
        {
                const typename D::type* data = static_cast<const typename D::type*>(contents);
                size_t data_length = size / sizeof(typename D::type);

                // first pass: get length in utf8 units
                size_t length = D::process(data, data_length, 0, utf8_counter());

                // allocate buffer of suitable length
                char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                if (!buffer) return false;

                // second pass: convert utf16 input to utf8
                uint8_t* obegin = reinterpret_cast<uint8_t*>(buffer);
                uint8_t* oend = D::process(data, data_length, obegin, utf8_writer());

                assert(oend == obegin + length);
                *oend = 0;

                out_buffer = buffer;
                out_length = length + 1;

                return true;
        }

        PUGI__FN size_t get_latin1_7bit_prefix_length(const uint8_t* data, size_t size)
        {
                for (size_t i = 0; i < size; ++i)
                        if (data[i] > 127)
                                return i;

                return size;
        }

        PUGI__FN bool convert_buffer_latin1(char_t*& out_buffer, size_t& out_length, const void* contents, size_t size, bool is_mutable)
        {
                const uint8_t* data = static_cast<const uint8_t*>(contents);
                size_t data_length = size;

                // get size of prefix that does not need utf8 conversion
                size_t prefix_length = get_latin1_7bit_prefix_length(data, data_length);
                assert(prefix_length <= data_length);

                const uint8_t* postfix = data + prefix_length;
                size_t postfix_length = data_length - prefix_length;

                // if no conversion is needed, just return the original buffer
                if (postfix_length == 0) return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

                // first pass: get length in utf8 units
                size_t length = prefix_length + latin1_decoder::process(postfix, postfix_length, 0, utf8_counter());

                // allocate buffer of suitable length
                char_t* buffer = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                if (!buffer) return false;

                // second pass: convert latin1 input to utf8
                memcpy(buffer, data, prefix_length);

                uint8_t* obegin = reinterpret_cast<uint8_t*>(buffer);
                uint8_t* oend = latin1_decoder::process(postfix, postfix_length, obegin + prefix_length, utf8_writer());

                assert(oend == obegin + length);
                *oend = 0;

                out_buffer = buffer;
                out_length = length + 1;

                return true;
        }

        PUGI__FN bool convert_buffer(char_t*& out_buffer, size_t& out_length, xml_encoding encoding, const void* contents, size_t size, bool is_mutable)
        {
                // fast path: no conversion required
                if (encoding == encoding_utf8)
                        return get_mutable_buffer(out_buffer, out_length, contents, size, is_mutable);

                // source encoding is utf16
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf16_decoder<opt_true>());
                }

                // source encoding is utf32
                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return (native_encoding == encoding) ?
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_false>()) :
                                convert_buffer_generic(out_buffer, out_length, contents, size, utf32_decoder<opt_true>());
                }

                // source encoding is latin1
                if (encoding == encoding_latin1)
                        return convert_buffer_latin1(out_buffer, out_length, contents, size, is_mutable);

                assert(false && "Invalid encoding"); // unreachable
                return false;
        }
#endif

        PUGI__FN size_t as_utf8_begin(const wchar_t* str, size_t length)
        {
                // get length in utf8 characters
                return wchar_decoder::process(str, length, 0, utf8_counter());
        }

        PUGI__FN void as_utf8_end(char* buffer, size_t size, const wchar_t* str, size_t length)
        {
                // convert to utf8
                uint8_t* begin = reinterpret_cast<uint8_t*>(buffer);
                uint8_t* end = wchar_decoder::process(str, length, begin, utf8_writer());

                assert(begin + size == end);
                (void)!end;
                (void)!size;
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN std::string as_utf8_impl(const wchar_t* str, size_t length)
        {
                // first pass: get length in utf8 characters
                size_t size = as_utf8_begin(str, length);

                // allocate resulting string
                std::string result;
                result.resize(size);

                // second pass: convert to utf8
                if (size > 0) as_utf8_end(&result[0], size, str, length);

                return result;
        }

        PUGI__FN std::basic_string<wchar_t> as_wide_impl(const char* str, size_t size)
        {
                const uint8_t* data = reinterpret_cast<const uint8_t*>(str);

                // first pass: get length in wchar_t units
                size_t length = utf8_decoder::process(data, size, 0, wchar_counter());

                // allocate resulting string
                std::basic_string<wchar_t> result;
                result.resize(length);

                // second pass: convert to wchar_t
                if (length > 0)
                {
                        wchar_writer::value_type begin = reinterpret_cast<wchar_writer::value_type>(&result[0]);
                        wchar_writer::value_type end = utf8_decoder::process(data, size, begin, wchar_writer());

                        assert(begin + length == end);
                        (void)!end;
                }

                return result;
        }
#endif

        template <typename Header>
        inline bool strcpy_insitu_allow(size_t length, const Header& header, uintptr_t header_mask, char_t* target)
        {
                // never reuse shared memory
                if (header & xml_memory_page_contents_shared_mask) return false;

                size_t target_length = strlength(target);

                // always reuse document buffer memory if possible
                if ((header & header_mask) == 0) return target_length >= length;

                // reuse heap memory if waste is not too great
                const size_t reuse_threshold = 32;

                return target_length >= length && (target_length < reuse_threshold || target_length - length < target_length / 2);
        }

        template <typename String, typename Header>
        PUGI__FN bool strcpy_insitu(String& dest, Header& header, uintptr_t header_mask, const char_t* source, size_t source_length)
        {
                if (source_length == 0)
                {
                        // empty string and null pointer are equivalent, so just deallocate old memory
                        xml_allocator* alloc = PUGI__GETPAGE_IMPL(header)->allocator;

                        if (header & header_mask) alloc->deallocate_string(dest);

                        // mark the string as not allocated
                        dest = 0;
                        header &= ~header_mask;

                        return true;
                }
                else if (dest && strcpy_insitu_allow(source_length, header, header_mask, dest))
                {
                        // we can reuse old buffer, so just copy the new data (including zero terminator)
                        memcpy(dest, source, source_length * sizeof(char_t));
                        dest[source_length] = 0;

                        return true;
                }
                else
                {
                        xml_allocator* alloc = PUGI__GETPAGE_IMPL(header)->allocator;

                        if (!alloc->reserve()) return false;

                        // allocate new buffer
                        char_t* buf = alloc->allocate_string(source_length + 1);
                        if (!buf) return false;

                        // copy the string (including zero terminator)
                        memcpy(buf, source, source_length * sizeof(char_t));
                        buf[source_length] = 0;

                        // deallocate old buffer (*after* the above to protect against overlapping memory and/or allocation failures)
                        if (header & header_mask) alloc->deallocate_string(dest);

                        // the string is now allocated, so set the flag
                        dest = buf;
                        header |= header_mask;

                        return true;
                }
        }

        struct gap
        {
                char_t* end;
                size_t size;

                gap(): end(0), size(0)
                {
                }

                // Push new gap, move s count bytes further (skipping the gap).
                // Collapse previous gap.
                void push(char_t*& s, size_t count)
                {
                        if (end) // there was a gap already; collapse it
                        {
                                // Move [old_gap_end, new_gap_start) to [old_gap_start, ...)
                                assert(s >= end);
                                memmove(end - size, end, reinterpret_cast<char*>(s) - reinterpret_cast<char*>(end));
                        }

                        s += count; // end of current gap

                        // "merge" two gaps
                        end = s;
                        size += count;
                }

                // Collapse all gaps, return past-the-end pointer
                char_t* flush(char_t* s)
                {
                        if (end)
                        {
                                // Move [old_gap_end, current_pos) to [old_gap_start, ...)
                                assert(s >= end);
                                memmove(end - size, end, reinterpret_cast<char*>(s) - reinterpret_cast<char*>(end));

                                return s - size;
                        }
                        else return s;
                }
        };

        PUGI__FN char_t* strconv_escape(char_t* s, gap& g)
        {
                char_t* stre = s + 1;

                switch (*stre)
                {
                        case '#':       // &#...
                        {
                                unsigned int ucsc = 0;

                                if (stre[1] == 'x') // &#x... (hex code)
                                {
                                        stre += 2;

                                        char_t ch = *stre;

                                        if (ch == ';') return stre;

                                        for (;;)
                                        {
                                                if (static_cast<unsigned int>(ch - '0') <= 9)
                                                        ucsc = 16 * ucsc + (ch - '0');
                                                else if (static_cast<unsigned int>((ch | ' ') - 'a') <= 5)
                                                        ucsc = 16 * ucsc + ((ch | ' ') - 'a' + 10);
                                                else if (ch == ';')
                                                        break;
                                                else // cancel
                                                        return stre;

                                                ch = *++stre;
                                        }

                                        ++stre;
                                }
                                else    // &#... (dec code)
                                {
                                        char_t ch = *++stre;

                                        if (ch == ';') return stre;

                                        for (;;)
                                        {
                                                if (static_cast<unsigned int>(ch - '0') <= 9)
                                                        ucsc = 10 * ucsc + (ch - '0');
                                                else if (ch == ';')
                                                        break;
                                                else // cancel
                                                        return stre;

                                                ch = *++stre;
                                        }

                                        ++stre;
                                }

                        #ifdef PUGIXML_WCHAR_MODE
                                s = reinterpret_cast<char_t*>(wchar_writer::any(reinterpret_cast<wchar_writer::value_type>(s), ucsc));
                        #else
                                s = reinterpret_cast<char_t*>(utf8_writer::any(reinterpret_cast<uint8_t*>(s), ucsc));
                        #endif

                                g.push(s, stre - s);
                                return stre;
                        }

                        case 'a':       // &a
                        {
                                ++stre;

                                if (*stre == 'm') // &am
                                {
                                        if (*++stre == 'p' && *++stre == ';') // &amp;
                                        {
                                                *s++ = '&';
                                                ++stre;

                                                g.push(s, stre - s);
                                                return stre;
                                        }
                                }
                                else if (*stre == 'p') // &ap
                                {
                                        if (*++stre == 'o' && *++stre == 's' && *++stre == ';') // &apos;
                                        {
                                                *s++ = '\'';
                                                ++stre;

                                                g.push(s, stre - s);
                                                return stre;
                                        }
                                }
                                break;
                        }

                        case 'g': // &g
                        {
                                if (*++stre == 't' && *++stre == ';') // &gt;
                                {
                                        *s++ = '>';
                                        ++stre;

                                        g.push(s, stre - s);
                                        return stre;
                                }
                                break;
                        }

                        case 'l': // &l
                        {
                                if (*++stre == 't' && *++stre == ';') // &lt;
                                {
                                        *s++ = '<';
                                        ++stre;

                                        g.push(s, stre - s);
                                        return stre;
                                }
                                break;
                        }

                        case 'q': // &q
                        {
                                if (*++stre == 'u' && *++stre == 'o' && *++stre == 't' && *++stre == ';') // &quot;
                                {
                                        *s++ = '"';
                                        ++stre;

                                        g.push(s, stre - s);
                                        return stre;
                                }
                                break;
                        }

                        default:
                                break;
                }

                return stre;
        }

        // Parser utilities
        #define PUGI__ENDSWITH(c, e)        ((c) == (e) || ((c) == 0 && endch == (e)))
        #define PUGI__SKIPWS()              { while (PUGI__IS_CHARTYPE(*s, ct_space)) ++s; }
        #define PUGI__OPTSET(OPT)           ( optmsk & (OPT) )
        #define PUGI__PUSHNODE(TYPE)        { cursor = append_new_node(cursor, *alloc, TYPE); if (!cursor) PUGI__THROW_ERROR(status_out_of_memory, s); }
        #define PUGI__POPNODE()             { cursor = cursor->parent; }
        #define PUGI__SCANFOR(X)            { while (*s != 0 && !(X)) ++s; }
        #define PUGI__SCANWHILE(X)          { while (X) ++s; }
        #define PUGI__SCANWHILE_UNROLL(X)   { for (;;) { char_t ss = s[0]; if (PUGI__UNLIKELY(!(X))) { break; } ss = s[1]; if (PUGI__UNLIKELY(!(X))) { s += 1; break; } ss = s[2]; if (PUGI__UNLIKELY(!(X))) { s += 2; break; } ss = s[3]; if (PUGI__UNLIKELY(!(X))) { s += 3; break; } s += 4; } }
        #define PUGI__ENDSEG()              { ch = *s; *s = 0; ++s; }
        #define PUGI__THROW_ERROR(err, m)   return error_offset = m, error_status = err, static_cast<char_t*>(0)
        #define PUGI__CHECK_ERROR(err, m)   { if (*s == 0) PUGI__THROW_ERROR(err, m); }

        PUGI__FN char_t* strconv_comment(char_t* s, char_t endch)
        {
                gap g;

                while (true)
                {
                        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_comment));

                        if (*s == '\r') // Either a single 0x0d or 0x0d 0x0a pair
                        {
                                *s++ = '\n'; // replace first one with 0x0a

                                if (*s == '\n') g.push(s, 1);
                        }
                        else if (s[0] == '-' && s[1] == '-' && PUGI__ENDSWITH(s[2], '>')) // comment ends here
                        {
                                *g.flush(s) = 0;

                                return s + (s[2] == '>' ? 3 : 2);
                        }
                        else if (*s == 0)
                        {
                                return 0;
                        }
                        else ++s;
                }
        }

        PUGI__FN char_t* strconv_cdata(char_t* s, char_t endch)
        {
                gap g;

                while (true)
                {
                        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_cdata));

                        if (*s == '\r') // Either a single 0x0d or 0x0d 0x0a pair
                        {
                                *s++ = '\n'; // replace first one with 0x0a

                                if (*s == '\n') g.push(s, 1);
                        }
                        else if (s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>')) // CDATA ends here
                        {
                                *g.flush(s) = 0;

                                return s + 1;
                        }
                        else if (*s == 0)
                        {
                                return 0;
                        }
                        else ++s;
                }
        }

        typedef char_t* (*strconv_pcdata_t)(char_t*);

        template <typename opt_trim, typename opt_eol, typename opt_escape> struct strconv_pcdata_impl
        {
                static char_t* parse(char_t* s)
                {
                        gap g;

                        char_t* begin = s;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_pcdata));

                                if (*s == '<') // PCDATA ends here
                                {
                                        char_t* end = g.flush(s);

                                        if (opt_trim::value)
                                                while (end > begin && PUGI__IS_CHARTYPE(end[-1], ct_space))
                                                        --end;

                                        *end = 0;

                                        return s + 1;
                                }
                                else if (opt_eol::value && *s == '\r') // Either a single 0x0d or 0x0d 0x0a pair
                                {
                                        *s++ = '\n'; // replace first one with 0x0a

                                        if (*s == '\n') g.push(s, 1);
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (*s == 0)
                                {
                                        char_t* end = g.flush(s);

                                        if (opt_trim::value)
                                                while (end > begin && PUGI__IS_CHARTYPE(end[-1], ct_space))
                                                        --end;

                                        *end = 0;

                                        return s;
                                }
                                else ++s;
                        }
                }
        };

        PUGI__FN strconv_pcdata_t get_strconv_pcdata(unsigned int optmask)
        {
                PUGI__STATIC_ASSERT(parse_escapes == 0x10 && parse_eol == 0x20 && parse_trim_pcdata == 0x0800);

                switch (((optmask >> 4) & 3) | ((optmask >> 9) & 4)) // get bitmask for flags (trim eol escapes); this simultaneously checks 3 options from assertion above
                {
                case 0: return strconv_pcdata_impl<opt_false, opt_false, opt_false>::parse;
                case 1: return strconv_pcdata_impl<opt_false, opt_false, opt_true>::parse;
                case 2: return strconv_pcdata_impl<opt_false, opt_true, opt_false>::parse;
                case 3: return strconv_pcdata_impl<opt_false, opt_true, opt_true>::parse;
                case 4: return strconv_pcdata_impl<opt_true, opt_false, opt_false>::parse;
                case 5: return strconv_pcdata_impl<opt_true, opt_false, opt_true>::parse;
                case 6: return strconv_pcdata_impl<opt_true, opt_true, opt_false>::parse;
                case 7: return strconv_pcdata_impl<opt_true, opt_true, opt_true>::parse;
                default: assert(false); return 0; // unreachable
                }
        }

        typedef char_t* (*strconv_attribute_t)(char_t*, char_t);

        template <typename opt_escape> struct strconv_attribute_impl
        {
                static char_t* parse_wnorm(char_t* s, char_t end_quote)
                {
                        gap g;

                        // trim leading whitespaces
                        if (PUGI__IS_CHARTYPE(*s, ct_space))
                        {
                                char_t* str = s;

                                do ++str;
                                while (PUGI__IS_CHARTYPE(*str, ct_space));

                                g.push(s, str - s);
                        }

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws | ct_space));

                                if (*s == end_quote)
                                {
                                        char_t* str = g.flush(s);

                                        do *str-- = 0;
                                        while (PUGI__IS_CHARTYPE(*str, ct_space));

                                        return s + 1;
                                }
                                else if (PUGI__IS_CHARTYPE(*s, ct_space))
                                {
                                        *s++ = ' ';

                                        if (PUGI__IS_CHARTYPE(*s, ct_space))
                                        {
                                                char_t* str = s + 1;
                                                while (PUGI__IS_CHARTYPE(*str, ct_space)) ++str;

                                                g.push(s, str - s);
                                        }
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }

                static char_t* parse_wconv(char_t* s, char_t end_quote)
                {
                        gap g;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr_ws));

                                if (*s == end_quote)
                                {
                                        *g.flush(s) = 0;

                                        return s + 1;
                                }
                                else if (PUGI__IS_CHARTYPE(*s, ct_space))
                                {
                                        if (*s == '\r')
                                        {
                                                *s++ = ' ';

                                                if (*s == '\n') g.push(s, 1);
                                        }
                                        else *s++ = ' ';
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }

                static char_t* parse_eol(char_t* s, char_t end_quote)
                {
                        gap g;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr));

                                if (*s == end_quote)
                                {
                                        *g.flush(s) = 0;

                                        return s + 1;
                                }
                                else if (*s == '\r')
                                {
                                        *s++ = '\n';

                                        if (*s == '\n') g.push(s, 1);
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }

                static char_t* parse_simple(char_t* s, char_t end_quote)
                {
                        gap g;

                        while (true)
                        {
                                PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPE(ss, ct_parse_attr));

                                if (*s == end_quote)
                                {
                                        *g.flush(s) = 0;

                                        return s + 1;
                                }
                                else if (opt_escape::value && *s == '&')
                                {
                                        s = strconv_escape(s, g);
                                }
                                else if (!*s)
                                {
                                        return 0;
                                }
                                else ++s;
                        }
                }
        };

        PUGI__FN strconv_attribute_t get_strconv_attribute(unsigned int optmask)
        {
                PUGI__STATIC_ASSERT(parse_escapes == 0x10 && parse_eol == 0x20 && parse_wconv_attribute == 0x40 && parse_wnorm_attribute == 0x80);

                switch ((optmask >> 4) & 15) // get bitmask for flags (wnorm wconv eol escapes); this simultaneously checks 4 options from assertion above
                {
                case 0:  return strconv_attribute_impl<opt_false>::parse_simple;
                case 1:  return strconv_attribute_impl<opt_true>::parse_simple;
                case 2:  return strconv_attribute_impl<opt_false>::parse_eol;
                case 3:  return strconv_attribute_impl<opt_true>::parse_eol;
                case 4:  return strconv_attribute_impl<opt_false>::parse_wconv;
                case 5:  return strconv_attribute_impl<opt_true>::parse_wconv;
                case 6:  return strconv_attribute_impl<opt_false>::parse_wconv;
                case 7:  return strconv_attribute_impl<opt_true>::parse_wconv;
                case 8:  return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 9:  return strconv_attribute_impl<opt_true>::parse_wnorm;
                case 10: return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 11: return strconv_attribute_impl<opt_true>::parse_wnorm;
                case 12: return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 13: return strconv_attribute_impl<opt_true>::parse_wnorm;
                case 14: return strconv_attribute_impl<opt_false>::parse_wnorm;
                case 15: return strconv_attribute_impl<opt_true>::parse_wnorm;
                default: assert(false); return 0; // unreachable
                }
        }

        inline xml_parse_result make_parse_result(xml_parse_status status, ptrdiff_t offset = 0)
        {
                xml_parse_result result;
                result.status = status;
                result.offset = offset;

                return result;
        }

        struct xml_parser
        {
                xml_allocator* alloc;
                char_t* error_offset;
                xml_parse_status error_status;

                xml_parser(xml_allocator* alloc_): alloc(alloc_), error_offset(0), error_status(status_ok)
                {
                }

                // DOCTYPE consists of nested sections of the following possible types:
                // <!-- ... -->, <? ... ?>, "...", '...'
                // <![...]]>
                // <!...>
                // First group can not contain nested groups
                // Second group can contain nested groups of the same type
                // Third group can contain all other groups
                char_t* parse_doctype_primitive(char_t* s)
                {
                        if (*s == '"' || *s == '\'')
                        {
                                // quoted string
                                char_t ch = *s++;
                                PUGI__SCANFOR(*s == ch);
                                if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

                                s++;
                        }
                        else if (s[0] == '<' && s[1] == '?')
                        {
                                // <? ... ?>
                                s += 2;
                                PUGI__SCANFOR(s[0] == '?' && s[1] == '>'); // no need for ENDSWITH because ?> can't terminate proper doctype
                                if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

                                s += 2;
                        }
                        else if (s[0] == '<' && s[1] == '!' && s[2] == '-' && s[3] == '-')
                        {
                                s += 4;
                                PUGI__SCANFOR(s[0] == '-' && s[1] == '-' && s[2] == '>'); // no need for ENDSWITH because --> can't terminate proper doctype
                                if (!*s) PUGI__THROW_ERROR(status_bad_doctype, s);

                                s += 3;
                        }
                        else PUGI__THROW_ERROR(status_bad_doctype, s);

                        return s;
                }

                char_t* parse_doctype_ignore(char_t* s)
                {
                        size_t depth = 0;

                        assert(s[0] == '<' && s[1] == '!' && s[2] == '[');
                        s += 3;

                        while (*s)
                        {
                                if (s[0] == '<' && s[1] == '!' && s[2] == '[')
                                {
                                        // nested ignore section
                                        s += 3;
                                        depth++;
                                }
                                else if (s[0] == ']' && s[1] == ']' && s[2] == '>')
                                {
                                        // ignore section end
                                        s += 3;

                                        if (depth == 0)
                                                return s;

                                        depth--;
                                }
                                else s++;
                        }

                        PUGI__THROW_ERROR(status_bad_doctype, s);
                }

                char_t* parse_doctype_group(char_t* s, char_t endch)
                {
                        size_t depth = 0;

                        assert((s[0] == '<' || s[0] == 0) && s[1] == '!');
                        s += 2;

                        while (*s)
                        {
                                if (s[0] == '<' && s[1] == '!' && s[2] != '-')
                                {
                                        if (s[2] == '[')
                                        {
                                                // ignore
                                                s = parse_doctype_ignore(s);
                                                if (!s) return s;
                                        }
                                        else
                                        {
                                                // some control group
                                                s += 2;
                                                depth++;
                                        }
                                }
                                else if (s[0] == '<' || s[0] == '"' || s[0] == '\'')
                                {
                                        // unknown tag (forbidden), or some primitive group
                                        s = parse_doctype_primitive(s);
                                        if (!s) return s;
                                }
                                else if (*s == '>')
                                {
                                        if (depth == 0)
                                                return s;

                                        depth--;
                                        s++;
                                }
                                else s++;
                        }

                        if (depth != 0 || endch != '>') PUGI__THROW_ERROR(status_bad_doctype, s);

                        return s;
                }

                char_t* parse_exclamation(char_t* s, xml_node_struct* cursor, unsigned int optmsk, char_t endch)
                {
                        // parse node contents, starting with exclamation mark
                        ++s;

                        if (*s == '-') // '<!-...'
                        {
                                ++s;

                                if (*s == '-') // '<!--...'
                                {
                                        ++s;

                                        if (PUGI__OPTSET(parse_comments))
                                        {
                                                PUGI__PUSHNODE(node_comment); // Append a new node on the tree.
                                                cursor->value = s; // Save the offset.
                                        }

                                        if (PUGI__OPTSET(parse_eol) && PUGI__OPTSET(parse_comments))
                                        {
                                                s = strconv_comment(s, endch);

                                                if (!s) PUGI__THROW_ERROR(status_bad_comment, cursor->value);
                                        }
                                        else
                                        {
                                                // Scan for terminating '-->'.
                                                PUGI__SCANFOR(s[0] == '-' && s[1] == '-' && PUGI__ENDSWITH(s[2], '>'));
                                                PUGI__CHECK_ERROR(status_bad_comment, s);

                                                if (PUGI__OPTSET(parse_comments))
                                                        *s = 0; // Zero-terminate this segment at the first terminating '-'.

                                                s += (s[2] == '>' ? 3 : 2); // Step over the '\0->'.
                                        }
                                }
                                else PUGI__THROW_ERROR(status_bad_comment, s);
                        }
                        else if (*s == '[')
                        {
                                // '<![CDATA[...'
                                if (*++s=='C' && *++s=='D' && *++s=='A' && *++s=='T' && *++s=='A' && *++s == '[')
                                {
                                        ++s;

                                        if (PUGI__OPTSET(parse_cdata))
                                        {
                                                PUGI__PUSHNODE(node_cdata); // Append a new node on the tree.
                                                cursor->value = s; // Save the offset.

                                                if (PUGI__OPTSET(parse_eol))
                                                {
                                                        s = strconv_cdata(s, endch);

                                                        if (!s) PUGI__THROW_ERROR(status_bad_cdata, cursor->value);
                                                }
                                                else
                                                {
                                                        // Scan for terminating ']]>'.
                                                        PUGI__SCANFOR(s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>'));
                                                        PUGI__CHECK_ERROR(status_bad_cdata, s);

                                                        *s++ = 0; // Zero-terminate this segment.
                                                }
                                        }
                                        else // Flagged for discard, but we still have to scan for the terminator.
                                        {
                                                // Scan for terminating ']]>'.
                                                PUGI__SCANFOR(s[0] == ']' && s[1] == ']' && PUGI__ENDSWITH(s[2], '>'));
                                                PUGI__CHECK_ERROR(status_bad_cdata, s);

                                                ++s;
                                        }

                                        s += (s[1] == '>' ? 2 : 1); // Step over the last ']>'.
                                }
                                else PUGI__THROW_ERROR(status_bad_cdata, s);
                        }
                        else if (s[0] == 'D' && s[1] == 'O' && s[2] == 'C' && s[3] == 'T' && s[4] == 'Y' && s[5] == 'P' && PUGI__ENDSWITH(s[6], 'E'))
                        {
                                s -= 2;

                                if (cursor->parent) PUGI__THROW_ERROR(status_bad_doctype, s);

                                char_t* mark = s + 9;

                                s = parse_doctype_group(s, endch);
                                if (!s) return s;

                                assert((*s == 0 && endch == '>') || *s == '>');
                                if (*s) *s++ = 0;

                                if (PUGI__OPTSET(parse_doctype))
                                {
                                        while (PUGI__IS_CHARTYPE(*mark, ct_space)) ++mark;

                                        PUGI__PUSHNODE(node_doctype);

                                        cursor->value = mark;
                                }
                        }
                        else if (*s == 0 && endch == '-') PUGI__THROW_ERROR(status_bad_comment, s);
                        else if (*s == 0 && endch == '[') PUGI__THROW_ERROR(status_bad_cdata, s);
                        else PUGI__THROW_ERROR(status_unrecognized_tag, s);

                        return s;
                }

                char_t* parse_question(char_t* s, xml_node_struct*& ref_cursor, unsigned int optmsk, char_t endch)
                {
                        // load into registers
                        xml_node_struct* cursor = ref_cursor;
                        char_t ch = 0;

                        // parse node contents, starting with question mark
                        ++s;

                        // read PI target
                        char_t* target = s;

                        if (!PUGI__IS_CHARTYPE(*s, ct_start_symbol)) PUGI__THROW_ERROR(status_bad_pi, s);

                        PUGI__SCANWHILE(PUGI__IS_CHARTYPE(*s, ct_symbol));
                        PUGI__CHECK_ERROR(status_bad_pi, s);

                        // determine node type; stricmp / strcasecmp is not portable
                        bool declaration = (target[0] | ' ') == 'x' && (target[1] | ' ') == 'm' && (target[2] | ' ') == 'l' && target + 3 == s;

                        if (declaration ? PUGI__OPTSET(parse_declaration) : PUGI__OPTSET(parse_pi))
                        {
                                if (declaration)
                                {
                                        // disallow non top-level declarations
                                        if (cursor->parent) PUGI__THROW_ERROR(status_bad_pi, s);

                                        PUGI__PUSHNODE(node_declaration);
                                }
                                else
                                {
                                        PUGI__PUSHNODE(node_pi);
                                }

                                cursor->name = target;

                                PUGI__ENDSEG();

                                // parse value/attributes
                                if (ch == '?')
                                {
                                        // empty node
                                        if (!PUGI__ENDSWITH(*s, '>')) PUGI__THROW_ERROR(status_bad_pi, s);
                                        s += (*s == '>');

                                        PUGI__POPNODE();
                                }
                                else if (PUGI__IS_CHARTYPE(ch, ct_space))
                                {
                                        PUGI__SKIPWS();

                                        // scan for tag end
                                        char_t* value = s;

                                        PUGI__SCANFOR(s[0] == '?' && PUGI__ENDSWITH(s[1], '>'));
                                        PUGI__CHECK_ERROR(status_bad_pi, s);

                                        if (declaration)
                                        {
                                                // replace ending ? with / so that 'element' terminates properly
                                                *s = '/';

                                                // we exit from this function with cursor at node_declaration, which is a signal to parse() to go to LOC_ATTRIBUTES
                                                s = value;
                                        }
                                        else
                                        {
                                                // store value and step over >
                                                cursor->value = value;

                                                PUGI__POPNODE();

                                                PUGI__ENDSEG();

                                                s += (*s == '>');
                                        }
                                }
                                else PUGI__THROW_ERROR(status_bad_pi, s);
                        }
                        else
                        {
                                // scan for tag end
                                PUGI__SCANFOR(s[0] == '?' && PUGI__ENDSWITH(s[1], '>'));
                                PUGI__CHECK_ERROR(status_bad_pi, s);

                                s += (s[1] == '>' ? 2 : 1);
                        }

                        // store from registers
                        ref_cursor = cursor;

                        return s;
                }

                char_t* parse_tree(char_t* s, xml_node_struct* root, unsigned int optmsk, char_t endch)
                {
                        strconv_attribute_t strconv_attribute = get_strconv_attribute(optmsk);
                        strconv_pcdata_t strconv_pcdata = get_strconv_pcdata(optmsk);

                        char_t ch = 0;
                        xml_node_struct* cursor = root;
                        char_t* mark = s;

                        while (*s != 0)
                        {
                                if (*s == '<')
                                {
                                        ++s;

                                LOC_TAG:
                                        if (PUGI__IS_CHARTYPE(*s, ct_start_symbol)) // '<#...'
                                        {
                                                PUGI__PUSHNODE(node_element); // Append a new node to the tree.

                                                cursor->name = s;

                                                PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol)); // Scan for a terminator.
                                                PUGI__ENDSEG(); // Save char in 'ch', terminate & step over.

                                                if (ch == '>')
                                                {
                                                        // end of tag
                                                }
                                                else if (PUGI__IS_CHARTYPE(ch, ct_space))
                                                {
                                                LOC_ATTRIBUTES:
                                                        while (true)
                                                        {
                                                                PUGI__SKIPWS(); // Eat any whitespace.

                                                                if (PUGI__IS_CHARTYPE(*s, ct_start_symbol)) // <... #...
                                                                {
                                                                        xml_attribute_struct* a = append_new_attribute(cursor, *alloc); // Make space for this attribute.
                                                                        if (!a) PUGI__THROW_ERROR(status_out_of_memory, s);

                                                                        a->name = s; // Save the offset.

                                                                        PUGI__SCANWHILE_UNROLL(PUGI__IS_CHARTYPE(ss, ct_symbol)); // Scan for a terminator.
                                                                        PUGI__ENDSEG(); // Save char in 'ch', terminate & step over.

                                                                        if (PUGI__IS_CHARTYPE(ch, ct_space))
                                                                        {
                                                                                PUGI__SKIPWS(); // Eat any whitespace.

                                                                                ch = *s;
                                                                                ++s;
                                                                        }

                                                                        if (ch == '=') // '<... #=...'
                                                                        {
                                                                                PUGI__SKIPWS(); // Eat any whitespace.

                                                                                if (*s == '"' || *s == '\'') // '<... #="...'
                                                                                {
                                                                                        ch = *s; // Save quote char to avoid breaking on "''" -or- '""'.
                                                                                        ++s; // Step over the quote.
                                                                                        a->value = s; // Save the offset.

                                                                                        s = strconv_attribute(s, ch);

                                                                                        if (!s) PUGI__THROW_ERROR(status_bad_attribute, a->value);

                                                                                        // After this line the loop continues from the start;
                                                                                        // Whitespaces, / and > are ok, symbols and EOF are wrong,
                                                                                        // everything else will be detected
                                                                                        if (PUGI__IS_CHARTYPE(*s, ct_start_symbol)) PUGI__THROW_ERROR(status_bad_attribute, s);
                                                                                }
                                                                                else PUGI__THROW_ERROR(status_bad_attribute, s);
                                                                        }
                                                                        else PUGI__THROW_ERROR(status_bad_attribute, s);
                                                                }
                                                                else if (*s == '/')
                                                                {
                                                                        ++s;

                                                                        if (*s == '>')
                                                                        {
                                                                                PUGI__POPNODE();
                                                                                s++;
                                                                                break;
                                                                        }
                                                                        else if (*s == 0 && endch == '>')
                                                                        {
                                                                                PUGI__POPNODE();
                                                                                break;
                                                                        }
                                                                        else PUGI__THROW_ERROR(status_bad_start_element, s);
                                                                }
                                                                else if (*s == '>')
                                                                {
                                                                        ++s;

                                                                        break;
                                                                }
                                                                else if (*s == 0 && endch == '>')
                                                                {
                                                                        break;
                                                                }
                                                                else PUGI__THROW_ERROR(status_bad_start_element, s);
                                                        }

                                                        // !!!
                                                }
                                                else if (ch == '/') // '<#.../'
                                                {
                                                        if (!PUGI__ENDSWITH(*s, '>')) PUGI__THROW_ERROR(status_bad_start_element, s);

                                                        PUGI__POPNODE(); // Pop.

                                                        s += (*s == '>');
                                                }
                                                else if (ch == 0)
                                                {
                                                        // we stepped over null terminator, backtrack & handle closing tag
                                                        --s;

                                                        if (endch != '>') PUGI__THROW_ERROR(status_bad_start_element, s);
                                                }
                                                else PUGI__THROW_ERROR(status_bad_start_element, s);
                                        }
                                        else if (*s == '/')
                                        {
                                                ++s;

                                                mark = s;

                                                char_t* name = cursor->name;
                                                if (!name) PUGI__THROW_ERROR(status_end_element_mismatch, mark);

                                                while (PUGI__IS_CHARTYPE(*s, ct_symbol))
                                                {
                                                        if (*s++ != *name++) PUGI__THROW_ERROR(status_end_element_mismatch, mark);
                                                }

                                                if (*name)
                                                {
                                                        if (*s == 0 && name[0] == endch && name[1] == 0) PUGI__THROW_ERROR(status_bad_end_element, s);
                                                        else PUGI__THROW_ERROR(status_end_element_mismatch, mark);
                                                }

                                                PUGI__POPNODE(); // Pop.

                                                PUGI__SKIPWS();

                                                if (*s == 0)
                                                {
                                                        if (endch != '>') PUGI__THROW_ERROR(status_bad_end_element, s);
                                                }
                                                else
                                                {
                                                        if (*s != '>') PUGI__THROW_ERROR(status_bad_end_element, s);
                                                        ++s;
                                                }
                                        }
                                        else if (*s == '?') // '<?...'
                                        {
                                                s = parse_question(s, cursor, optmsk, endch);
                                                if (!s) return s;

                                                assert(cursor);
                                                if (PUGI__NODETYPE(cursor) == node_declaration) goto LOC_ATTRIBUTES;
                                        }
                                        else if (*s == '!') // '<!...'
                                        {
                                                s = parse_exclamation(s, cursor, optmsk, endch);
                                                if (!s) return s;
                                        }
                                        else if (*s == 0 && endch == '?') PUGI__THROW_ERROR(status_bad_pi, s);
                                        else PUGI__THROW_ERROR(status_unrecognized_tag, s);
                                }
                                else
                                {
                                        mark = s; // Save this offset while searching for a terminator.

                                        PUGI__SKIPWS(); // Eat whitespace if no genuine PCDATA here.

                                        if (*s == '<' || !*s)
                                        {
                                                // We skipped some whitespace characters because otherwise we would take the tag branch instead of PCDATA one
                                                assert(mark != s);

                                                if (!PUGI__OPTSET(parse_ws_pcdata | parse_ws_pcdata_single) || PUGI__OPTSET(parse_trim_pcdata))
                                                {
                                                        continue;
                                                }
                                                else if (PUGI__OPTSET(parse_ws_pcdata_single))
                                                {
                                                        if (s[0] != '<' || s[1] != '/' || cursor->first_child) continue;
                                                }
                                        }

                                        if (!PUGI__OPTSET(parse_trim_pcdata))
                                                s = mark;

                                        if (cursor->parent || PUGI__OPTSET(parse_fragment))
                                        {
                                                if (PUGI__OPTSET(parse_embed_pcdata) && cursor->parent && !cursor->first_child && !cursor->value)
                                                {
                                                        cursor->value = s; // Save the offset.
                                                }
                                                else
                                                {
                                                        PUGI__PUSHNODE(node_pcdata); // Append a new node on the tree.

                                                        cursor->value = s; // Save the offset.

                                                        PUGI__POPNODE(); // Pop since this is a standalone.
                                                }

                                                s = strconv_pcdata(s);

                                                if (!*s) break;
                                        }
                                        else
                                        {
                                                PUGI__SCANFOR(*s == '<'); // '...<'
                                                if (!*s) break;

                                                ++s;
                                        }

                                        // We're after '<'
                                        goto LOC_TAG;
                                }
                        }

                        // check that last tag is closed
                        if (cursor != root) PUGI__THROW_ERROR(status_end_element_mismatch, s);

                        return s;
                }

        #ifdef PUGIXML_WCHAR_MODE
                static char_t* parse_skip_bom(char_t* s)
                {
                        unsigned int bom = 0xfeff;
                        return (s[0] == static_cast<wchar_t>(bom)) ? s + 1 : s;
                }
        #else
                static char_t* parse_skip_bom(char_t* s)
                {
                        return (s[0] == '\xef' && s[1] == '\xbb' && s[2] == '\xbf') ? s + 3 : s;
                }
        #endif

                static bool has_element_node_siblings(xml_node_struct* node)
                {
                        while (node)
                        {
                                if (PUGI__NODETYPE(node) == node_element) return true;

                                node = node->next_sibling;
                        }

                        return false;
                }

                static xml_parse_result parse(char_t* buffer, size_t length, xml_document_struct* xmldoc, xml_node_struct* root, unsigned int optmsk)
                {
                        // early-out for empty documents
                        if (length == 0)
                                return make_parse_result(PUGI__OPTSET(parse_fragment) ? status_ok : status_no_document_element);

                        // get last child of the root before parsing
                        xml_node_struct* last_root_child = root->first_child ? root->first_child->prev_sibling_c + 0 : 0;

                        // create parser on stack
                        xml_parser parser(static_cast<xml_allocator*>(xmldoc));

                        // save last character and make buffer zero-terminated (speeds up parsing)
                        char_t endch = buffer[length - 1];
                        buffer[length - 1] = 0;

                        // skip BOM to make sure it does not end up as part of parse output
                        char_t* buffer_data = parse_skip_bom(buffer);

                        // perform actual parsing
                        parser.parse_tree(buffer_data, root, optmsk, endch);

                        xml_parse_result result = make_parse_result(parser.error_status, parser.error_offset ? parser.error_offset - buffer : 0);
                        assert(result.offset >= 0 && static_cast<size_t>(result.offset) <= length);

                        if (result)
                        {
                                // since we removed last character, we have to handle the only possible false positive (stray <)
                                if (endch == '<')
                                        return make_parse_result(status_unrecognized_tag, length - 1);

                                // check if there are any element nodes parsed
                                xml_node_struct* first_root_child_parsed = last_root_child ? last_root_child->next_sibling + 0 : root->first_child+ 0;

                                if (!PUGI__OPTSET(parse_fragment) && !has_element_node_siblings(first_root_child_parsed))
                                        return make_parse_result(status_no_document_element, length - 1);
                        }
                        else
                        {
                                // roll back offset if it occurs on a null terminator in the source buffer
                                if (result.offset > 0 && static_cast<size_t>(result.offset) == length - 1 && endch == 0)
                                        result.offset--;
                        }

                        return result;
                }
        };

        // Output facilities
        PUGI__FN xml_encoding get_write_native_encoding()
        {
        #ifdef PUGIXML_WCHAR_MODE
                return get_wchar_encoding();
        #else
                return encoding_utf8;
        #endif
        }

        PUGI__FN xml_encoding get_write_encoding(xml_encoding encoding)
        {
                // replace wchar encoding with utf implementation
                if (encoding == encoding_wchar) return get_wchar_encoding();

                // replace utf16 encoding with utf16 with specific endianness
                if (encoding == encoding_utf16) return is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                // replace utf32 encoding with utf32 with specific endianness
                if (encoding == encoding_utf32) return is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                // only do autodetection if no explicit encoding is requested
                if (encoding != encoding_auto) return encoding;

                // assume utf8 encoding
                return encoding_utf8;
        }

        template <typename D, typename T> PUGI__FN size_t convert_buffer_output_generic(typename T::value_type dest, const char_t* data, size_t length, D, T)
        {
                PUGI__STATIC_ASSERT(sizeof(char_t) == sizeof(typename D::type));

                typename T::value_type end = D::process(reinterpret_cast<const typename D::type*>(data), length, dest, T());

                return static_cast<size_t>(end - dest) * sizeof(*dest);
        }

        template <typename D, typename T> PUGI__FN size_t convert_buffer_output_generic(typename T::value_type dest, const char_t* data, size_t length, D, T, bool opt_swap)
        {
                PUGI__STATIC_ASSERT(sizeof(char_t) == sizeof(typename D::type));

                typename T::value_type end = D::process(reinterpret_cast<const typename D::type*>(data), length, dest, T());

                if (opt_swap)
                {
                        for (typename T::value_type i = dest; i != end; ++i)
                                *i = endian_swap(*i);
                }

                return static_cast<size_t>(end - dest) * sizeof(*dest);
        }

#ifdef PUGIXML_WCHAR_MODE
        PUGI__FN size_t get_valid_length(const char_t* data, size_t length)
        {
                if (length < 1) return 0;

                // discard last character if it's the lead of a surrogate pair
                return (sizeof(wchar_t) == 2 && static_cast<unsigned int>(static_cast<uint16_t>(data[length - 1]) - 0xD800) < 0x400) ? length - 1 : length;
        }

        PUGI__FN size_t convert_buffer_output(char_t* r_char, uint8_t* r_u8, uint16_t* r_u16, uint32_t* r_u32, const char_t* data, size_t length, xml_encoding encoding)
        {
                // only endian-swapping is required
                if (need_endian_swap_utf(encoding, get_wchar_encoding()))
                {
                        convert_wchar_endian_swap(r_char, data, length);

                        return length * sizeof(char_t);
                }

                // convert to utf8
                if (encoding == encoding_utf8)
                        return convert_buffer_output_generic(r_u8, data, length, wchar_decoder(), utf8_writer());

                // convert to utf16
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return convert_buffer_output_generic(r_u16, data, length, wchar_decoder(), utf16_writer(), native_encoding != encoding);
                }

                // convert to utf32
                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return convert_buffer_output_generic(r_u32, data, length, wchar_decoder(), utf32_writer(), native_encoding != encoding);
                }

                // convert to latin1
                if (encoding == encoding_latin1)
                        return convert_buffer_output_generic(r_u8, data, length, wchar_decoder(), latin1_writer());

                assert(false && "Invalid encoding"); // unreachable
                return 0;
        }
#else
        PUGI__FN size_t get_valid_length(const char_t* data, size_t length)
        {
                if (length < 5) return 0;

                for (size_t i = 1; i <= 4; ++i)
                {
                        uint8_t ch = static_cast<uint8_t>(data[length - i]);

                        // either a standalone character or a leading one
                        if ((ch & 0xc0) != 0x80) return length - i;
                }

                // there are four non-leading characters at the end, sequence tail is broken so might as well process the whole chunk
                return length;
        }

        PUGI__FN size_t convert_buffer_output(char_t* /* r_char */, uint8_t* r_u8, uint16_t* r_u16, uint32_t* r_u32, const char_t* data, size_t length, xml_encoding encoding)
        {
                if (encoding == encoding_utf16_be || encoding == encoding_utf16_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf16_le : encoding_utf16_be;

                        return convert_buffer_output_generic(r_u16, data, length, utf8_decoder(), utf16_writer(), native_encoding != encoding);
                }

                if (encoding == encoding_utf32_be || encoding == encoding_utf32_le)
                {
                        xml_encoding native_encoding = is_little_endian() ? encoding_utf32_le : encoding_utf32_be;

                        return convert_buffer_output_generic(r_u32, data, length, utf8_decoder(), utf32_writer(), native_encoding != encoding);
                }

                if (encoding == encoding_latin1)
                        return convert_buffer_output_generic(r_u8, data, length, utf8_decoder(), latin1_writer());

                assert(false && "Invalid encoding"); // unreachable
                return 0;
        }
#endif

        class xml_buffered_writer
        {
                xml_buffered_writer(const xml_buffered_writer&);
                xml_buffered_writer& operator=(const xml_buffered_writer&);

        public:
                xml_buffered_writer(xml_writer& writer_, xml_encoding user_encoding): writer(writer_), bufsize(0), encoding(get_write_encoding(user_encoding))
                {
                        PUGI__STATIC_ASSERT(bufcapacity >= 8);
                }

                size_t flush()
                {
                        flush(buffer, bufsize);
                        bufsize = 0;
                        return 0;
                }

                void flush(const char_t* data, size_t size)
                {
                        if (size == 0) return;

                        // fast path, just write data
                        if (encoding == get_write_native_encoding())
                                writer.write(data, size * sizeof(char_t));
                        else
                        {
                                // convert chunk
                                size_t result = convert_buffer_output(scratch.data_char, scratch.data_u8, scratch.data_u16, scratch.data_u32, data, size, encoding);
                                assert(result <= sizeof(scratch));

                                // write data
                                writer.write(scratch.data_u8, result);
                        }
                }

                void write_direct(const char_t* data, size_t length)
                {
                        // flush the remaining buffer contents
                        flush();

                        // handle large chunks
                        if (length > bufcapacity)
                        {
                                if (encoding == get_write_native_encoding())
                                {
                                        // fast path, can just write data chunk
                                        writer.write(data, length * sizeof(char_t));
                                        return;
                                }

                                // need to convert in suitable chunks
                                while (length > bufcapacity)
                                {
                                        // get chunk size by selecting such number of characters that are guaranteed to fit into scratch buffer
                                        // and form a complete codepoint sequence (i.e. discard start of last codepoint if necessary)
                                        size_t chunk_size = get_valid_length(data, bufcapacity);
                                        assert(chunk_size);

                                        // convert chunk and write
                                        flush(data, chunk_size);

                                        // iterate
                                        data += chunk_size;
                                        length -= chunk_size;
                                }

                                // small tail is copied below
                                bufsize = 0;
                        }

                        memcpy(buffer + bufsize, data, length * sizeof(char_t));
                        bufsize += length;
                }

                void write_buffer(const char_t* data, size_t length)
                {
                        size_t offset = bufsize;

                        if (offset + length <= bufcapacity)
                        {
                                memcpy(buffer + offset, data, length * sizeof(char_t));
                                bufsize = offset + length;
                        }
                        else
                        {
                                write_direct(data, length);
                        }
                }

                void write_string(const char_t* data)
                {
                        // write the part of the string that fits in the buffer
                        size_t offset = bufsize;

                        while (*data && offset < bufcapacity)
                                buffer[offset++] = *data++;

                        // write the rest
                        if (offset < bufcapacity)
                        {
                                bufsize = offset;
                        }
                        else
                        {
                                // backtrack a bit if we have split the codepoint
                                size_t length = offset - bufsize;
                                size_t extra = length - get_valid_length(data - length, length);

                                bufsize = offset - extra;

                                write_direct(data - extra, strlength(data) + extra);
                        }
                }

                void write(char_t d0)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 1) offset = flush();

                        buffer[offset + 0] = d0;
                        bufsize = offset + 1;
                }

                void write(char_t d0, char_t d1)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 2) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        bufsize = offset + 2;
                }

                void write(char_t d0, char_t d1, char_t d2)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 3) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        bufsize = offset + 3;
                }

                void write(char_t d0, char_t d1, char_t d2, char_t d3)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 4) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        buffer[offset + 3] = d3;
                        bufsize = offset + 4;
                }

                void write(char_t d0, char_t d1, char_t d2, char_t d3, char_t d4)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 5) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        buffer[offset + 3] = d3;
                        buffer[offset + 4] = d4;
                        bufsize = offset + 5;
                }

                void write(char_t d0, char_t d1, char_t d2, char_t d3, char_t d4, char_t d5)
                {
                        size_t offset = bufsize;
                        if (offset > bufcapacity - 6) offset = flush();

                        buffer[offset + 0] = d0;
                        buffer[offset + 1] = d1;
                        buffer[offset + 2] = d2;
                        buffer[offset + 3] = d3;
                        buffer[offset + 4] = d4;
                        buffer[offset + 5] = d5;
                        bufsize = offset + 6;
                }

                // utf8 maximum expansion: x4 (-> utf32)
                // utf16 maximum expansion: x2 (-> utf32)
                // utf32 maximum expansion: x1
                enum
                {
                        bufcapacitybytes =
                        #ifdef PUGIXML_MEMORY_OUTPUT_STACK
                                PUGIXML_MEMORY_OUTPUT_STACK
                        #else
                                10240
                        #endif
                        ,
                        bufcapacity = bufcapacitybytes / (sizeof(char_t) + 4)
                };

                char_t buffer[bufcapacity];

                union
                {
                        uint8_t data_u8[4 * bufcapacity];
                        uint16_t data_u16[2 * bufcapacity];
                        uint32_t data_u32[bufcapacity];
                        char_t data_char[bufcapacity];
                } scratch;

                xml_writer& writer;
                size_t bufsize;
                xml_encoding encoding;
        };

        PUGI__FN void text_output_escaped(xml_buffered_writer& writer, const char_t* s, chartypex_t type)
        {
                while (*s)
                {
                        const char_t* prev = s;

                        // While *s is a usual symbol
                        PUGI__SCANWHILE_UNROLL(!PUGI__IS_CHARTYPEX(ss, type));

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        switch (*s)
                        {
                                case 0: break;
                                case '&':
                                        writer.write('&', 'a', 'm', 'p', ';');
                                        ++s;
                                        break;
                                case '<':
                                        writer.write('&', 'l', 't', ';');
                                        ++s;
                                        break;
                                case '>':
                                        writer.write('&', 'g', 't', ';');
                                        ++s;
                                        break;
                                case '"':
                                        writer.write('&', 'q', 'u', 'o', 't', ';');
                                        ++s;
                                        break;
                                default: // s is not a usual symbol
                                {
                                        unsigned int ch = static_cast<unsigned int>(*s++);
                                        assert(ch < 32);

                                        writer.write('&', '#', static_cast<char_t>((ch / 10) + '0'), static_cast<char_t>((ch % 10) + '0'), ';');
                                }
                        }
                }
        }

        PUGI__FN void text_output(xml_buffered_writer& writer, const char_t* s, chartypex_t type, unsigned int flags)
        {
                if (flags & format_no_escapes)
                        writer.write_string(s);
                else
                        text_output_escaped(writer, s, type);
        }

        PUGI__FN void text_output_cdata(xml_buffered_writer& writer, const char_t* s)
        {
                do
                {
                        writer.write('<', '!', '[', 'C', 'D');
                        writer.write('A', 'T', 'A', '[');

                        const char_t* prev = s;

                        // look for ]]> sequence - we can't output it as is since it terminates CDATA
                        while (*s && !(s[0] == ']' && s[1] == ']' && s[2] == '>')) ++s;

                        // skip ]] if we stopped at ]]>, > will go to the next CDATA section
                        if (*s) s += 2;

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        writer.write(']', ']', '>');
                }
                while (*s);
        }

        PUGI__FN void text_output_indent(xml_buffered_writer& writer, const char_t* indent, size_t indent_length, unsigned int depth)
        {
                switch (indent_length)
                {
                case 1:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0]);
                        break;
                }

                case 2:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0], indent[1]);
                        break;
                }

                case 3:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0], indent[1], indent[2]);
                        break;
                }

                case 4:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write(indent[0], indent[1], indent[2], indent[3]);
                        break;
                }

                default:
                {
                        for (unsigned int i = 0; i < depth; ++i)
                                writer.write_buffer(indent, indent_length);
                }
                }
        }

        PUGI__FN void node_output_comment(xml_buffered_writer& writer, const char_t* s)
        {
                writer.write('<', '!', '-', '-');

                while (*s)
                {
                        const char_t* prev = s;

                        // look for -\0 or -- sequence - we can't output it since -- is illegal in comment body
                        while (*s && !(s[0] == '-' && (s[1] == '-' || s[1] == 0))) ++s;

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        if (*s)
                        {
                                assert(*s == '-');

                                writer.write('-', ' ');
                                ++s;
                        }
                }

                writer.write('-', '-', '>');
        }

        PUGI__FN void node_output_pi_value(xml_buffered_writer& writer, const char_t* s)
        {
                while (*s)
                {
                        const char_t* prev = s;

                        // look for ?> sequence - we can't output it since ?> terminates PI
                        while (*s && !(s[0] == '?' && s[1] == '>')) ++s;

                        writer.write_buffer(prev, static_cast<size_t>(s - prev));

                        if (*s)
                        {
                                assert(s[0] == '?' && s[1] == '>');

                                writer.write('?', ' ', '>');
                                s += 2;
                        }
                }
        }

        PUGI__FN void node_output_attributes(xml_buffered_writer& writer, xml_node_struct* node, const char_t* indent, size_t indent_length, unsigned int flags, unsigned int depth)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");

                for (xml_attribute_struct* a = node->first_attribute; a; a = a->next_attribute)
                {
                        if ((flags & (format_indent_attributes | format_raw)) == format_indent_attributes)
                        {
                                writer.write('\n');

                                text_output_indent(writer, indent, indent_length, depth + 1);
                        }
                        else
                        {
                                writer.write(' ');
                        }

                        writer.write_string(a->name ? a->name + 0 : default_name);
                        writer.write('=', '"');

                        if (a->value)
                                text_output(writer, a->value, ctx_special_attr, flags);

                        writer.write('"');
                }
        }

        PUGI__FN bool node_output_start(xml_buffered_writer& writer, xml_node_struct* node, const char_t* indent, size_t indent_length, unsigned int flags, unsigned int depth)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");
                const char_t* name = node->name ? node->name + 0 : default_name;

                writer.write('<');
                writer.write_string(name);

                if (node->first_attribute)
                        node_output_attributes(writer, node, indent, indent_length, flags, depth);

                // element nodes can have value if parse_embed_pcdata was used
                if (!node->value)
                {
                        if (!node->first_child)
                        {
                                if (flags & format_no_empty_element_tags)
                                {
                                        writer.write('>', '<', '/');
                                        writer.write_string(name);
                                        writer.write('>');

                                        return false;
                                }
                                else
                                {
                                        if ((flags & format_raw) == 0)
                                                writer.write(' ');

                                        writer.write('/', '>');

                                        return false;
                                }
                        }
                        else
                        {
                                writer.write('>');

                                return true;
                        }
                }
                else
                {
                        writer.write('>');

                        text_output(writer, node->value, ctx_special_pcdata, flags);

                        if (!node->first_child)
                        {
                                writer.write('<', '/');
                                writer.write_string(name);
                                writer.write('>');

                                return false;
                        }
                        else
                        {
                                return true;
                        }
                }
        }

        PUGI__FN void node_output_end(xml_buffered_writer& writer, xml_node_struct* node)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");
                const char_t* name = node->name ? node->name + 0 : default_name;

                writer.write('<', '/');
                writer.write_string(name);
                writer.write('>');
        }

        PUGI__FN void node_output_simple(xml_buffered_writer& writer, xml_node_struct* node, unsigned int flags)
        {
                const char_t* default_name = PUGIXML_TEXT(":anonymous");

                switch (PUGI__NODETYPE(node))
                {
                        case node_pcdata:
                                text_output(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""), ctx_special_pcdata, flags);
                                break;

                        case node_cdata:
                                text_output_cdata(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""));
                                break;

                        case node_comment:
                                node_output_comment(writer, node->value ? node->value + 0 : PUGIXML_TEXT(""));
                                break;

                        case node_pi:
                                writer.write('<', '?');
                                writer.write_string(node->name ? node->name + 0 : default_name);

                                if (node->value)
                                {
                                        writer.write(' ');
                                        node_output_pi_value(writer, node->value);
                                }

                                writer.write('?', '>');
                                break;

                        case node_declaration:
                                writer.write('<', '?');
                                writer.write_string(node->name ? node->name + 0 : default_name);
                                node_output_attributes(writer, node, PUGIXML_TEXT(""), 0, flags | format_raw, 0);
                                writer.write('?', '>');
                                break;

                        case node_doctype:
                                writer.write('<', '!', 'D', 'O', 'C');
                                writer.write('T', 'Y', 'P', 'E');

                                if (node->value)
                                {
                                        writer.write(' ');
                                        writer.write_string(node->value);
                                }

                                writer.write('>');
                                break;

                        default:
                                assert(false && "Invalid node type"); // unreachable
                }
        }

        enum indent_flags_t
        {
                indent_newline = 1,
                indent_indent = 2
        };

        PUGI__FN void node_output(xml_buffered_writer& writer, xml_node_struct* root, const char_t* indent, unsigned int flags, unsigned int depth)
        {
                size_t indent_length = ((flags & (format_indent | format_indent_attributes)) && (flags & format_raw) == 0) ? strlength(indent) : 0;
                unsigned int indent_flags = indent_indent;

                xml_node_struct* node = root;

                do
                {
                        assert(node);

                        // begin writing current node
                        if (PUGI__NODETYPE(node) == node_pcdata || PUGI__NODETYPE(node) == node_cdata)
                        {
                                node_output_simple(writer, node, flags);

                                indent_flags = 0;
                        }
                        else
                        {
                                if ((indent_flags & indent_newline) && (flags & format_raw) == 0)
                                        writer.write('\n');

                                if ((indent_flags & indent_indent) && indent_length)
                                        text_output_indent(writer, indent, indent_length, depth);

                                if (PUGI__NODETYPE(node) == node_element)
                                {
                                        indent_flags = indent_newline | indent_indent;

                                        if (node_output_start(writer, node, indent, indent_length, flags, depth))
                                        {
                                                // element nodes can have value if parse_embed_pcdata was used
                                                if (node->value)
                                                        indent_flags = 0;

                                                node = node->first_child;
                                                depth++;
                                                continue;
                                        }
                                }
                                else if (PUGI__NODETYPE(node) == node_document)
                                {
                                        indent_flags = indent_indent;

                                        if (node->first_child)
                                        {
                                                node = node->first_child;
                                                continue;
                                        }
                                }
                                else
                                {
                                        node_output_simple(writer, node, flags);

                                        indent_flags = indent_newline | indent_indent;
                                }
                        }

                        // continue to the next node
                        while (node != root)
                        {
                                if (node->next_sibling)
                                {
                                        node = node->next_sibling;
                                        break;
                                }

                                node = node->parent;

                                // write closing node
                                if (PUGI__NODETYPE(node) == node_element)
                                {
                                        depth--;

                                        if ((indent_flags & indent_newline) && (flags & format_raw) == 0)
                                                writer.write('\n');

                                        if ((indent_flags & indent_indent) && indent_length)
                                                text_output_indent(writer, indent, indent_length, depth);

                                        node_output_end(writer, node);

                                        indent_flags = indent_newline | indent_indent;
                                }
                        }
                }
                while (node != root);

                if ((indent_flags & indent_newline) && (flags & format_raw) == 0)
                        writer.write('\n');
        }

        PUGI__FN bool has_declaration(xml_node_struct* node)
        {
                for (xml_node_struct* child = node->first_child; child; child = child->next_sibling)
                {
                        xml_node_type type = PUGI__NODETYPE(child);

                        if (type == node_declaration) return true;
                        if (type == node_element) return false;
                }

                return false;
        }

        PUGI__FN bool is_attribute_of(xml_attribute_struct* attr, xml_node_struct* node)
        {
                for (xml_attribute_struct* a = node->first_attribute; a; a = a->next_attribute)
                        if (a == attr)
                                return true;

                return false;
        }

        PUGI__FN bool allow_insert_attribute(xml_node_type parent)
        {
                return parent == node_element || parent == node_declaration;
        }

        PUGI__FN bool allow_insert_child(xml_node_type parent, xml_node_type child)
        {
                if (parent != node_document && parent != node_element) return false;
                if (child == node_document || child == node_null) return false;
                if (parent != node_document && (child == node_declaration || child == node_doctype)) return false;

                return true;
        }

        PUGI__FN bool allow_move(xml_node parent, xml_node child)
        {
                // check that child can be a child of parent
                if (!allow_insert_child(parent.type(), child.type()))
                        return false;

                // check that node is not moved between documents
                if (parent.root() != child.root())
                        return false;

                // check that new parent is not in the child subtree
                xml_node cur = parent;

                while (cur)
                {
                        if (cur == child)
                                return false;

                        cur = cur.parent();
                }

                return true;
        }

        template <typename String, typename Header>
        PUGI__FN void node_copy_string(String& dest, Header& header, uintptr_t header_mask, char_t* source, Header& source_header, xml_allocator* alloc)
        {
                assert(!dest && (header & header_mask) == 0);

                if (source)
                {
                        if (alloc && (source_header & header_mask) == 0)
                        {
                                dest = source;

                                // since strcpy_insitu can reuse document buffer memory we need to mark both source and dest as shared
                                header |= xml_memory_page_contents_shared_mask;
                                source_header |= xml_memory_page_contents_shared_mask;
                        }
                        else
                                strcpy_insitu(dest, header, header_mask, source, strlength(source));
                }
        }

        PUGI__FN void node_copy_contents(xml_node_struct* dn, xml_node_struct* sn, xml_allocator* shared_alloc)
        {
                node_copy_string(dn->name, dn->header, xml_memory_page_name_allocated_mask, sn->name, sn->header, shared_alloc);
                node_copy_string(dn->value, dn->header, xml_memory_page_value_allocated_mask, sn->value, sn->header, shared_alloc);

                for (xml_attribute_struct* sa = sn->first_attribute; sa; sa = sa->next_attribute)
                {
                        xml_attribute_struct* da = append_new_attribute(dn, get_allocator(dn));

                        if (da)
                        {
                                node_copy_string(da->name, da->header, xml_memory_page_name_allocated_mask, sa->name, sa->header, shared_alloc);
                                node_copy_string(da->value, da->header, xml_memory_page_value_allocated_mask, sa->value, sa->header, shared_alloc);
                        }
                }
        }

        PUGI__FN void node_copy_tree(xml_node_struct* dn, xml_node_struct* sn)
        {
                xml_allocator& alloc = get_allocator(dn);
                xml_allocator* shared_alloc = (&alloc == &get_allocator(sn)) ? &alloc : 0;

                node_copy_contents(dn, sn, shared_alloc);

                xml_node_struct* dit = dn;
                xml_node_struct* sit = sn->first_child;

                while (sit && sit != sn)
                {
                        // when a tree is copied into one of the descendants, we need to skip that subtree to avoid an infinite loop
                        if (sit != dn)
                        {
                                xml_node_struct* copy = append_new_node(dit, alloc, PUGI__NODETYPE(sit));

                                if (copy)
                                {
                                        node_copy_contents(copy, sit, shared_alloc);

                                        if (sit->first_child)
                                        {
                                                dit = copy;
                                                sit = sit->first_child;
                                                continue;
                                        }
                                }
                        }

                        // continue to the next node
                        do
                        {
                                if (sit->next_sibling)
                                {
                                        sit = sit->next_sibling;
                                        break;
                                }

                                sit = sit->parent;
                                dit = dit->parent;
                        }
                        while (sit != sn);
                }
        }

        PUGI__FN void node_copy_attribute(xml_attribute_struct* da, xml_attribute_struct* sa)
        {
                xml_allocator& alloc = get_allocator(da);
                xml_allocator* shared_alloc = (&alloc == &get_allocator(sa)) ? &alloc : 0;

                node_copy_string(da->name, da->header, xml_memory_page_name_allocated_mask, sa->name, sa->header, shared_alloc);
                node_copy_string(da->value, da->header, xml_memory_page_value_allocated_mask, sa->value, sa->header, shared_alloc);
        }

        inline bool is_text_node(xml_node_struct* node)
        {
                xml_node_type type = PUGI__NODETYPE(node);

                return type == node_pcdata || type == node_cdata;
        }

        // get value with conversion functions
        template <typename U> PUGI__FN PUGI__UNSIGNED_OVERFLOW U string_to_integer(const char_t* value, U minv, U maxv)
        {
                U result = 0;
                const char_t* s = value;

                while (PUGI__IS_CHARTYPE(*s, ct_space))
                        s++;

                bool negative = (*s == '-');

                s += (*s == '+' || *s == '-');

                bool overflow = false;

                if (s[0] == '0' && (s[1] | ' ') == 'x')
                {
                        s += 2;

                        // since overflow detection relies on length of the sequence skip leading zeros
                        while (*s == '0')
                                s++;

                        const char_t* start = s;

                        for (;;)
                        {
                                if (static_cast<unsigned>(*s - '0') < 10)
                                        result = result * 16 + (*s - '0');
                                else if (static_cast<unsigned>((*s | ' ') - 'a') < 6)
                                        result = result * 16 + ((*s | ' ') - 'a' + 10);
                                else
                                        break;

                                s++;
                        }

                        size_t digits = static_cast<size_t>(s - start);

                        overflow = digits > sizeof(U) * 2;
                }
                else
                {
                        // since overflow detection relies on length of the sequence skip leading zeros
                        while (*s == '0')
                                s++;

                        const char_t* start = s;

                        for (;;)
                        {
                                if (static_cast<unsigned>(*s - '0') < 10)
                                        result = result * 10 + (*s - '0');
                                else
                                        break;

                                s++;
                        }

                        size_t digits = static_cast<size_t>(s - start);

                        PUGI__STATIC_ASSERT(sizeof(U) == 8 || sizeof(U) == 4 || sizeof(U) == 2);

                        const size_t max_digits10 = sizeof(U) == 8 ? 20 : sizeof(U) == 4 ? 10 : 5;
                        const char_t max_lead = sizeof(U) == 8 ? '1' : sizeof(U) == 4 ? '4' : '6';
                        const size_t high_bit = sizeof(U) * 8 - 1;

                        overflow = digits >= max_digits10 && !(digits == max_digits10 && (*start < max_lead || (*start == max_lead && result >> high_bit)));
                }

                if (negative)
                {
                        // Workaround for crayc++ CC-3059: Expected no overflow in routine.
                #ifdef _CRAYC
                        return (overflow || result > ~minv + 1) ? minv : ~result + 1;
                #else
                        return (overflow || result > 0 - minv) ? minv : 0 - result;
                #endif
                }
                else
                        return (overflow || result > maxv) ? maxv : result;
        }

        PUGI__FN int get_value_int(const char_t* value)
        {
                return string_to_integer<unsigned int>(value, static_cast<unsigned int>(INT_MIN), INT_MAX);
        }

        PUGI__FN unsigned int get_value_uint(const char_t* value)
        {
                return string_to_integer<unsigned int>(value, 0, UINT_MAX);
        }

        PUGI__FN double get_value_double(const char_t* value)
        {
        #ifdef PUGIXML_WCHAR_MODE
                return wcstod(value, 0);
        #else
                return strtod(value, 0);
        #endif
        }

        PUGI__FN float get_value_float(const char_t* value)
        {
        #ifdef PUGIXML_WCHAR_MODE
                return static_cast<float>(wcstod(value, 0));
        #else
                return static_cast<float>(strtod(value, 0));
        #endif
        }

        PUGI__FN bool get_value_bool(const char_t* value)
        {
                // only look at first char
                char_t first = *value;

                // 1*, t* (true), T* (True), y* (yes), Y* (YES)
                return (first == '1' || first == 't' || first == 'T' || first == 'y' || first == 'Y');
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN long long get_value_llong(const char_t* value)
        {
                return string_to_integer<unsigned long long>(value, static_cast<unsigned long long>(LLONG_MIN), LLONG_MAX);
        }

        PUGI__FN unsigned long long get_value_ullong(const char_t* value)
        {
                return string_to_integer<unsigned long long>(value, 0, ULLONG_MAX);
        }
#endif

        template <typename U> PUGI__FN PUGI__UNSIGNED_OVERFLOW char_t* integer_to_string(char_t* begin, char_t* end, U value, bool negative)
        {
                char_t* result = end - 1;
                U rest = negative ? 0 - value : value;

                do
                {
                        *result-- = static_cast<char_t>('0' + (rest % 10));
                        rest /= 10;
                }
                while (rest);

                assert(result >= begin);
                (void)begin;

                *result = '-';

                return result + !negative;
        }

        // set value with conversion functions
        template <typename String, typename Header>
        PUGI__FN bool set_value_ascii(String& dest, Header& header, uintptr_t header_mask, char* buf)
        {
        #ifdef PUGIXML_WCHAR_MODE
                char_t wbuf[128];
                assert(strlen(buf) < sizeof(wbuf) / sizeof(wbuf[0]));

                size_t offset = 0;
                for (; buf[offset]; ++offset) wbuf[offset] = buf[offset];

                return strcpy_insitu(dest, header, header_mask, wbuf, offset);
        #else
                return strcpy_insitu(dest, header, header_mask, buf, strlen(buf));
        #endif
        }

        template <typename U, typename String, typename Header>
        PUGI__FN bool set_value_integer(String& dest, Header& header, uintptr_t header_mask, U value, bool negative)
        {
                char_t buf[64];
                char_t* end = buf + sizeof(buf) / sizeof(buf[0]);
                char_t* begin = integer_to_string(buf, end, value, negative);

                return strcpy_insitu(dest, header, header_mask, begin, end - begin);
        }

        template <typename String, typename Header>
        PUGI__FN bool set_value_convert(String& dest, Header& header, uintptr_t header_mask, float value)
        {
                char buf[128];
                PUGI__SNPRINTF(buf, "%.9g", value);

                return set_value_ascii(dest, header, header_mask, buf);
        }

        template <typename String, typename Header>
        PUGI__FN bool set_value_convert(String& dest, Header& header, uintptr_t header_mask, double value)
        {
                char buf[128];
                PUGI__SNPRINTF(buf, "%.17g", value);

                return set_value_ascii(dest, header, header_mask, buf);
        }

        template <typename String, typename Header>
        PUGI__FN bool set_value_bool(String& dest, Header& header, uintptr_t header_mask, bool value)
        {
                return strcpy_insitu(dest, header, header_mask, value ? PUGIXML_TEXT("true") : PUGIXML_TEXT("false"), value ? 4 : 5);
        }

        PUGI__FN xml_parse_result load_buffer_impl(xml_document_struct* doc, xml_node_struct* root, void* contents, size_t size, unsigned int options, xml_encoding encoding, bool is_mutable, bool own, char_t** out_buffer)
        {
                // check input buffer
                if (!contents && size) return make_parse_result(status_io_error);

                // get actual encoding
                xml_encoding buffer_encoding = impl::get_buffer_encoding(encoding, contents, size);

                // get private buffer
                char_t* buffer = 0;
                size_t length = 0;

                if (!impl::convert_buffer(buffer, length, buffer_encoding, contents, size, is_mutable)) return impl::make_parse_result(status_out_of_memory);

                // delete original buffer if we performed a conversion
                if (own && buffer != contents && contents) impl::xml_memory::deallocate(contents);

                // grab onto buffer if it's our buffer, user is responsible for deallocating contents himself
                if (own || buffer != contents) *out_buffer = buffer;

                // store buffer for offset_debug
                doc->buffer = buffer;

                // parse
                xml_parse_result res = impl::xml_parser::parse(buffer, length, doc, root, options);

                // remember encoding
                res.encoding = buffer_encoding;

                return res;
        }

        // we need to get length of entire file to load it in memory; the only (relatively) sane way to do it is via seek/tell trick
        PUGI__FN xml_parse_status get_file_size(FILE* file, size_t& out_result)
        {
        #if defined(PUGI__MSVC_CRT_VERSION) && PUGI__MSVC_CRT_VERSION >= 1400 && !defined(_WIN32_WCE)
                // there are 64-bit versions of fseek/ftell, let's use them
                typedef __int64 length_type;

                _fseeki64(file, 0, SEEK_END);
                length_type length = _ftelli64(file);
                _fseeki64(file, 0, SEEK_SET);
        #elif defined(__MINGW32__) && !defined(__NO_MINGW_LFS) && (!defined(__STRICT_ANSI__) || defined(__MINGW64_VERSION_MAJOR))
                // there are 64-bit versions of fseek/ftell, let's use them
                typedef off64_t length_type;

                fseeko64(file, 0, SEEK_END);
                length_type length = ftello64(file);
                fseeko64(file, 0, SEEK_SET);
        #else
                // if this is a 32-bit OS, long is enough; if this is a unix system, long is 64-bit, which is enough; otherwise we can't do anything anyway.
                typedef long length_type;

                fseek(file, 0, SEEK_END);
                length_type length = ftell(file);
                fseek(file, 0, SEEK_SET);
        #endif

                // check for I/O errors
                if (length < 0) return status_io_error;

                // check for overflow
                size_t result = static_cast<size_t>(length);

                if (static_cast<length_type>(result) != length) return status_out_of_memory;

                // finalize
                out_result = result;

                return status_ok;
        }

        // This function assumes that buffer has extra sizeof(char_t) writable bytes after size
        PUGI__FN size_t zero_terminate_buffer(void* buffer, size_t size, xml_encoding encoding)
        {
                // We only need to zero-terminate if encoding conversion does not do it for us
        #ifdef PUGIXML_WCHAR_MODE
                xml_encoding wchar_encoding = get_wchar_encoding();

                if (encoding == wchar_encoding || need_endian_swap_utf(encoding, wchar_encoding))
                {
                        size_t length = size / sizeof(char_t);

                        static_cast<char_t*>(buffer)[length] = 0;
                        return (length + 1) * sizeof(char_t);
                }
        #else
                if (encoding == encoding_utf8)
                {
                        static_cast<char*>(buffer)[size] = 0;
                        return size + 1;
                }
        #endif

                return size;
        }

        PUGI__FN xml_parse_result load_file_impl(xml_document_struct* doc, FILE* file, unsigned int options, xml_encoding encoding, char_t** out_buffer)
        {
                if (!file) return make_parse_result(status_file_not_found);

                // get file size (can result in I/O errors)
                size_t size = 0;
                xml_parse_status size_status = get_file_size(file, size);
                if (size_status != status_ok) return make_parse_result(size_status);

                size_t max_suffix_size = sizeof(char_t);

                // allocate buffer for the whole file
                char* contents = static_cast<char*>(xml_memory::allocate(size + max_suffix_size));
                if (!contents) return make_parse_result(status_out_of_memory);

                // read file in memory
                size_t read_size = fread(contents, 1, size, file);

                if (read_size != size)
                {
                        xml_memory::deallocate(contents);
                        return make_parse_result(status_io_error);
                }

                xml_encoding real_encoding = get_buffer_encoding(encoding, contents, size);

                return load_buffer_impl(doc, doc, contents, zero_terminate_buffer(contents, size, real_encoding), options, real_encoding, true, true, out_buffer);
        }

        PUGI__FN void close_file(FILE* file)
        {
                fclose(file);
        }

#ifndef PUGIXML_NO_STL
        template <typename T> struct xml_stream_chunk
        {
                static xml_stream_chunk* create()
                {
                        void* memory = xml_memory::allocate(sizeof(xml_stream_chunk));
                        if (!memory) return 0;

                        return new (memory) xml_stream_chunk();
                }

                static void destroy(xml_stream_chunk* chunk)
                {
                        // free chunk chain
                        while (chunk)
                        {
                                xml_stream_chunk* next_ = chunk->next;

                                xml_memory::deallocate(chunk);

                                chunk = next_;
                        }
                }

                xml_stream_chunk(): next(0), size(0)
                {
                }

                xml_stream_chunk* next;
                size_t size;

                T data[xml_memory_page_size / sizeof(T)];
        };

        template <typename T> PUGI__FN xml_parse_status load_stream_data_noseek(std::basic_istream<T>& stream, void** out_buffer, size_t* out_size)
        {
                auto_deleter<xml_stream_chunk<T> > chunks(0, xml_stream_chunk<T>::destroy);

                // read file to a chunk list
                size_t total = 0;
                xml_stream_chunk<T>* last = 0;

                while (!stream.eof())
                {
                        // allocate new chunk
                        xml_stream_chunk<T>* chunk = xml_stream_chunk<T>::create();
                        if (!chunk) return status_out_of_memory;

                        // append chunk to list
                        if (last) last = last->next = chunk;
                        else chunks.data = last = chunk;

                        // read data to chunk
                        stream.read(chunk->data, static_cast<std::streamsize>(sizeof(chunk->data) / sizeof(T)));
                        chunk->size = static_cast<size_t>(stream.gcount()) * sizeof(T);

                        // read may set failbit | eofbit in case gcount() is less than read length, so check for other I/O errors
                        if (stream.bad() || (!stream.eof() && stream.fail())) return status_io_error;

                        // guard against huge files (chunk size is small enough to make this overflow check work)
                        if (total + chunk->size < total) return status_out_of_memory;
                        total += chunk->size;
                }

                size_t max_suffix_size = sizeof(char_t);

                // copy chunk list to a contiguous buffer
                char* buffer = static_cast<char*>(xml_memory::allocate(total + max_suffix_size));
                if (!buffer) return status_out_of_memory;

                char* write = buffer;

                for (xml_stream_chunk<T>* chunk = chunks.data; chunk; chunk = chunk->next)
                {
                        assert(write + chunk->size <= buffer + total);
                        memcpy(write, chunk->data, chunk->size);
                        write += chunk->size;
                }

                assert(write == buffer + total);

                // return buffer
                *out_buffer = buffer;
                *out_size = total;

                return status_ok;
        }

        template <typename T> PUGI__FN xml_parse_status load_stream_data_seek(std::basic_istream<T>& stream, void** out_buffer, size_t* out_size)
        {
                // get length of remaining data in stream
                typename std::basic_istream<T>::pos_type pos = stream.tellg();
                stream.seekg(0, std::ios::end);
                std::streamoff length = stream.tellg() - pos;
                stream.seekg(pos);

                if (stream.fail() || pos < 0) return status_io_error;

                // guard against huge files
                size_t read_length = static_cast<size_t>(length);

                if (static_cast<std::streamsize>(read_length) != length || length < 0) return status_out_of_memory;

                size_t max_suffix_size = sizeof(char_t);

                // read stream data into memory (guard against stream exceptions with buffer holder)
                auto_deleter<void> buffer(xml_memory::allocate(read_length * sizeof(T) + max_suffix_size), xml_memory::deallocate);
                if (!buffer.data) return status_out_of_memory;

                stream.read(static_cast<T*>(buffer.data), static_cast<std::streamsize>(read_length));

                // read may set failbit | eofbit in case gcount() is less than read_length (i.e. line ending conversion), so check for other I/O errors
                if (stream.bad() || (!stream.eof() && stream.fail())) return status_io_error;

                // return buffer
                size_t actual_length = static_cast<size_t>(stream.gcount());
                assert(actual_length <= read_length);

                *out_buffer = buffer.release();
                *out_size = actual_length * sizeof(T);

                return status_ok;
        }

        template <typename T> PUGI__FN xml_parse_result load_stream_impl(xml_document_struct* doc, std::basic_istream<T>& stream, unsigned int options, xml_encoding encoding, char_t** out_buffer)
        {
                void* buffer = 0;
                size_t size = 0;
                xml_parse_status status = status_ok;

                // if stream has an error bit set, bail out (otherwise tellg() can fail and we'll clear error bits)
                if (stream.fail()) return make_parse_result(status_io_error);

                // load stream to memory (using seek-based implementation if possible, since it's faster and takes less memory)
                if (stream.tellg() < 0)
                {
                        stream.clear(); // clear error flags that could be set by a failing tellg
                        status = load_stream_data_noseek(stream, &buffer, &size);
                }
                else
                        status = load_stream_data_seek(stream, &buffer, &size);

                if (status != status_ok) return make_parse_result(status);

                xml_encoding real_encoding = get_buffer_encoding(encoding, buffer, size);

                return load_buffer_impl(doc, doc, buffer, zero_terminate_buffer(buffer, size, real_encoding), options, real_encoding, true, true, out_buffer);
        }
#endif

#if defined(PUGI__MSVC_CRT_VERSION) || defined(__BORLANDC__) || (defined(__MINGW32__) && (!defined(__STRICT_ANSI__) || defined(__MINGW64_VERSION_MAJOR)))
        PUGI__FN FILE* open_file_wide(const wchar_t* path, const wchar_t* mode)
        {
                return _wfopen(path, mode);
        }
#else
        PUGI__FN char* convert_path_heap(const wchar_t* str)
        {
                assert(str);

                // first pass: get length in utf8 characters
                size_t length = strlength_wide(str);
                size_t size = as_utf8_begin(str, length);

                // allocate resulting string
                char* result = static_cast<char*>(xml_memory::allocate(size + 1));
                if (!result) return 0;

                // second pass: convert to utf8
                as_utf8_end(result, size, str, length);

                // zero-terminate
                result[size] = 0;

                return result;
        }

        PUGI__FN FILE* open_file_wide(const wchar_t* path, const wchar_t* mode)
        {
                // there is no standard function to open wide paths, so our best bet is to try utf8 path
                char* path_utf8 = convert_path_heap(path);
                if (!path_utf8) return 0;

                // convert mode to ASCII (we mirror _wfopen interface)
                char mode_ascii[4] = {0};
                for (size_t i = 0; mode[i]; ++i) mode_ascii[i] = static_cast<char>(mode[i]);

                // try to open the utf8 path
                FILE* result = fopen(path_utf8, mode_ascii);

                // free dummy buffer
                xml_memory::deallocate(path_utf8);

                return result;
        }
#endif

        PUGI__FN bool save_file_impl(const xml_document& doc, FILE* file, const char_t* indent, unsigned int flags, xml_encoding encoding)
        {
                if (!file) return false;

                xml_writer_file writer(file);
                doc.save(writer, indent, flags, encoding);

                return ferror(file) == 0;
        }

        struct name_null_sentry
        {
                xml_node_struct* node;
                char_t* name;

                name_null_sentry(xml_node_struct* node_): node(node_), name(node_->name)
                {
                        node->name = 0;
                }

                ~name_null_sentry()
                {
                        node->name = name;
                }
        };
PUGI__NS_END

namespace pugi
{
        PUGI__FN xml_writer_file::xml_writer_file(void* file_): file(file_)
        {
        }

        PUGI__FN void xml_writer_file::write(const void* data, size_t size)
        {
                size_t result = fwrite(data, 1, size, static_cast<FILE*>(file));
                (void)!result; // unfortunately we can't do proper error handling here
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN xml_writer_stream::xml_writer_stream(std::basic_ostream<char, std::char_traits<char> >& stream): narrow_stream(&stream), wide_stream(0)
        {
        }

        PUGI__FN xml_writer_stream::xml_writer_stream(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream): narrow_stream(0), wide_stream(&stream)
        {
        }

        PUGI__FN void xml_writer_stream::write(const void* data, size_t size)
        {
                if (narrow_stream)
                {
                        assert(!wide_stream);
                        narrow_stream->write(reinterpret_cast<const char*>(data), static_cast<std::streamsize>(size));
                }
                else
                {
                        assert(wide_stream);
                        assert(size % sizeof(wchar_t) == 0);

                        wide_stream->write(reinterpret_cast<const wchar_t*>(data), static_cast<std::streamsize>(size / sizeof(wchar_t)));
                }
        }
#endif

        PUGI__FN xml_tree_walker::xml_tree_walker(): _depth(0)
        {
        }

        PUGI__FN xml_tree_walker::~xml_tree_walker()
        {
        }

        PUGI__FN int xml_tree_walker::depth() const
        {
                return _depth;
        }

        PUGI__FN bool xml_tree_walker::begin(xml_node&)
        {
                return true;
        }

        PUGI__FN bool xml_tree_walker::end(xml_node&)
        {
                return true;
        }

        PUGI__FN xml_attribute::xml_attribute(): _attr(0)
        {
        }

        PUGI__FN xml_attribute::xml_attribute(xml_attribute_struct* attr): _attr(attr)
        {
        }

        PUGI__FN static void unspecified_bool_xml_attribute(xml_attribute***)
        {
        }

        PUGI__FN xml_attribute::operator xml_attribute::unspecified_bool_type() const
        {
                return _attr ? unspecified_bool_xml_attribute : 0;
        }

        PUGI__FN bool xml_attribute::operator!() const
        {
                return !_attr;
        }

        PUGI__FN bool xml_attribute::operator==(const xml_attribute& r) const
        {
                return (_attr == r._attr);
        }

        PUGI__FN bool xml_attribute::operator!=(const xml_attribute& r) const
        {
                return (_attr != r._attr);
        }

        PUGI__FN bool xml_attribute::operator<(const xml_attribute& r) const
        {
                return (_attr < r._attr);
        }

        PUGI__FN bool xml_attribute::operator>(const xml_attribute& r) const
        {
                return (_attr > r._attr);
        }

        PUGI__FN bool xml_attribute::operator<=(const xml_attribute& r) const
        {
                return (_attr <= r._attr);
        }

        PUGI__FN bool xml_attribute::operator>=(const xml_attribute& r) const
        {
                return (_attr >= r._attr);
        }

        PUGI__FN xml_attribute xml_attribute::next_attribute() const
        {
                return _attr ? xml_attribute(_attr->next_attribute) : xml_attribute();
        }

        PUGI__FN xml_attribute xml_attribute::previous_attribute() const
        {
                return _attr && _attr->prev_attribute_c->next_attribute ? xml_attribute(_attr->prev_attribute_c) : xml_attribute();
        }

        PUGI__FN const char_t* xml_attribute::as_string(const char_t* def) const
        {
                return (_attr && _attr->value) ? _attr->value + 0 : def;
        }

        PUGI__FN int xml_attribute::as_int(int def) const
        {
                return (_attr && _attr->value) ? impl::get_value_int(_attr->value) : def;
        }

        PUGI__FN unsigned int xml_attribute::as_uint(unsigned int def) const
        {
                return (_attr && _attr->value) ? impl::get_value_uint(_attr->value) : def;
        }

        PUGI__FN double xml_attribute::as_double(double def) const
        {
                return (_attr && _attr->value) ? impl::get_value_double(_attr->value) : def;
        }

        PUGI__FN float xml_attribute::as_float(float def) const
        {
                return (_attr && _attr->value) ? impl::get_value_float(_attr->value) : def;
        }

        PUGI__FN bool xml_attribute::as_bool(bool def) const
        {
                return (_attr && _attr->value) ? impl::get_value_bool(_attr->value) : def;
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN long long xml_attribute::as_llong(long long def) const
        {
                return (_attr && _attr->value) ? impl::get_value_llong(_attr->value) : def;
        }

        PUGI__FN unsigned long long xml_attribute::as_ullong(unsigned long long def) const
        {
                return (_attr && _attr->value) ? impl::get_value_ullong(_attr->value) : def;
        }
#endif

        PUGI__FN bool xml_attribute::empty() const
        {
                return !_attr;
        }

        PUGI__FN const char_t* xml_attribute::name() const
        {
                return (_attr && _attr->name) ? _attr->name + 0 : PUGIXML_TEXT("");
        }

        PUGI__FN const char_t* xml_attribute::value() const
        {
                return (_attr && _attr->value) ? _attr->value + 0 : PUGIXML_TEXT("");
        }

        PUGI__FN size_t xml_attribute::hash_value() const
        {
                return static_cast<size_t>(reinterpret_cast<uintptr_t>(_attr) / sizeof(xml_attribute_struct));
        }

        PUGI__FN xml_attribute_struct* xml_attribute::internal_object() const
        {
                return _attr;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(const char_t* rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(int rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(unsigned int rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(long rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(unsigned long rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(double rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(float rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(bool rhs)
        {
                set_value(rhs);
                return *this;
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN xml_attribute& xml_attribute::operator=(long long rhs)
        {
                set_value(rhs);
                return *this;
        }

        PUGI__FN xml_attribute& xml_attribute::operator=(unsigned long long rhs)
        {
                set_value(rhs);
                return *this;
        }
#endif

        PUGI__FN bool xml_attribute::set_name(const char_t* rhs)
        {
                if (!_attr) return false;

                return impl::strcpy_insitu(_attr->name, _attr->header, impl::xml_memory_page_name_allocated_mask, rhs, impl::strlength(rhs));
        }

        PUGI__FN bool xml_attribute::set_value(const char_t* rhs)
        {
                if (!_attr) return false;

                return impl::strcpy_insitu(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs));
        }

        PUGI__FN bool xml_attribute::set_value(int rhs)
        {
                if (!_attr) return false;

                return impl::set_value_integer<unsigned int>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0);
        }

        PUGI__FN bool xml_attribute::set_value(unsigned int rhs)
        {
                if (!_attr) return false;

                return impl::set_value_integer<unsigned int>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, false);
        }

        PUGI__FN bool xml_attribute::set_value(long rhs)
        {
                if (!_attr) return false;

                return impl::set_value_integer<unsigned long>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0);
        }

        PUGI__FN bool xml_attribute::set_value(unsigned long rhs)
        {
                if (!_attr) return false;

                return impl::set_value_integer<unsigned long>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, false);
        }

        PUGI__FN bool xml_attribute::set_value(double rhs)
        {
                if (!_attr) return false;

                return impl::set_value_convert(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs);
        }

        PUGI__FN bool xml_attribute::set_value(float rhs)
        {
                if (!_attr) return false;

                return impl::set_value_convert(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs);
        }

        PUGI__FN bool xml_attribute::set_value(bool rhs)
        {
                if (!_attr) return false;

                return impl::set_value_bool(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs);
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN bool xml_attribute::set_value(long long rhs)
        {
                if (!_attr) return false;

                return impl::set_value_integer<unsigned long long>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0);
        }

        PUGI__FN bool xml_attribute::set_value(unsigned long long rhs)
        {
                if (!_attr) return false;

                return impl::set_value_integer<unsigned long long>(_attr->value, _attr->header, impl::xml_memory_page_value_allocated_mask, rhs, false);
        }
#endif

#ifdef __BORLANDC__
        PUGI__FN bool operator&&(const xml_attribute& lhs, bool rhs)
        {
                return (bool)lhs && rhs;
        }

        PUGI__FN bool operator||(const xml_attribute& lhs, bool rhs)
        {
                return (bool)lhs || rhs;
        }
#endif

        PUGI__FN xml_node::xml_node(): _root(0)
        {
        }

        PUGI__FN xml_node::xml_node(xml_node_struct* p): _root(p)
        {
        }

        PUGI__FN static void unspecified_bool_xml_node(xml_node***)
        {
        }

        PUGI__FN xml_node::operator xml_node::unspecified_bool_type() const
        {
                return _root ? unspecified_bool_xml_node : 0;
        }

        PUGI__FN bool xml_node::operator!() const
        {
                return !_root;
        }

        PUGI__FN xml_node::iterator xml_node::begin() const
        {
                return iterator(_root ? _root->first_child + 0 : 0, _root);
        }

        PUGI__FN xml_node::iterator xml_node::end() const
        {
                return iterator(0, _root);
        }

        PUGI__FN xml_node::attribute_iterator xml_node::attributes_begin() const
        {
                return attribute_iterator(_root ? _root->first_attribute + 0 : 0, _root);
        }

        PUGI__FN xml_node::attribute_iterator xml_node::attributes_end() const
        {
                return attribute_iterator(0, _root);
        }

        PUGI__FN xml_object_range<xml_node_iterator> xml_node::children() const
        {
                return xml_object_range<xml_node_iterator>(begin(), end());
        }

        PUGI__FN xml_object_range<xml_named_node_iterator> xml_node::children(const char_t* name_) const
        {
                return xml_object_range<xml_named_node_iterator>(xml_named_node_iterator(child(name_)._root, _root, name_), xml_named_node_iterator(0, _root, name_));
        }

        PUGI__FN xml_object_range<xml_attribute_iterator> xml_node::attributes() const
        {
                return xml_object_range<xml_attribute_iterator>(attributes_begin(), attributes_end());
        }

        PUGI__FN bool xml_node::operator==(const xml_node& r) const
        {
                return (_root == r._root);
        }

        PUGI__FN bool xml_node::operator!=(const xml_node& r) const
        {
                return (_root != r._root);
        }

        PUGI__FN bool xml_node::operator<(const xml_node& r) const
        {
                return (_root < r._root);
        }

        PUGI__FN bool xml_node::operator>(const xml_node& r) const
        {
                return (_root > r._root);
        }

        PUGI__FN bool xml_node::operator<=(const xml_node& r) const
        {
                return (_root <= r._root);
        }

        PUGI__FN bool xml_node::operator>=(const xml_node& r) const
        {
                return (_root >= r._root);
        }

        PUGI__FN bool xml_node::empty() const
        {
                return !_root;
        }

        PUGI__FN const char_t* xml_node::name() const
        {
                return (_root && _root->name) ? _root->name + 0 : PUGIXML_TEXT("");
        }

        PUGI__FN xml_node_type xml_node::type() const
        {
                return _root ? PUGI__NODETYPE(_root) : node_null;
        }

        PUGI__FN const char_t* xml_node::value() const
        {
                return (_root && _root->value) ? _root->value + 0 : PUGIXML_TEXT("");
        }

        PUGI__FN xml_node xml_node::child(const char_t* name_) const
        {
                if (!_root) return xml_node();

                for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
                        if (i->name && impl::strequal(name_, i->name)) return xml_node(i);

                return xml_node();
        }

        PUGI__FN xml_attribute xml_node::attribute(const char_t* name_) const
        {
                if (!_root) return xml_attribute();

                for (xml_attribute_struct* i = _root->first_attribute; i; i = i->next_attribute)
                        if (i->name && impl::strequal(name_, i->name))
                                return xml_attribute(i);

                return xml_attribute();
        }

        PUGI__FN xml_node xml_node::next_sibling(const char_t* name_) const
        {
                if (!_root) return xml_node();

                for (xml_node_struct* i = _root->next_sibling; i; i = i->next_sibling)
                        if (i->name && impl::strequal(name_, i->name)) return xml_node(i);

                return xml_node();
        }

        PUGI__FN xml_node xml_node::next_sibling() const
        {
                return _root ? xml_node(_root->next_sibling) : xml_node();
        }

        PUGI__FN xml_node xml_node::previous_sibling(const char_t* name_) const
        {
                if (!_root) return xml_node();

                for (xml_node_struct* i = _root->prev_sibling_c; i->next_sibling; i = i->prev_sibling_c)
                        if (i->name && impl::strequal(name_, i->name)) return xml_node(i);

                return xml_node();
        }

        PUGI__FN xml_attribute xml_node::attribute(const char_t* name_, xml_attribute& hint_) const
        {
                xml_attribute_struct* hint = hint_._attr;

                // if hint is not an attribute of node, behavior is not defined
                assert(!hint || (_root && impl::is_attribute_of(hint, _root)));

                if (!_root) return xml_attribute();

                // optimistically search from hint up until the end
                for (xml_attribute_struct* i = hint; i; i = i->next_attribute)
                        if (i->name && impl::strequal(name_, i->name))
                        {
                                // update hint to maximize efficiency of searching for consecutive attributes
                                hint_._attr = i->next_attribute;

                                return xml_attribute(i);
                        }

                // wrap around and search from the first attribute until the hint
                // 'j' null pointer check is technically redundant, but it prevents a crash in case the assertion above fails
                for (xml_attribute_struct* j = _root->first_attribute; j && j != hint; j = j->next_attribute)
                        if (j->name && impl::strequal(name_, j->name))
                        {
                                // update hint to maximize efficiency of searching for consecutive attributes
                                hint_._attr = j->next_attribute;

                                return xml_attribute(j);
                        }

                return xml_attribute();
        }

        PUGI__FN xml_node xml_node::previous_sibling() const
        {
                if (!_root) return xml_node();

                if (_root->prev_sibling_c->next_sibling) return xml_node(_root->prev_sibling_c);
                else return xml_node();
        }

        PUGI__FN xml_node xml_node::parent() const
        {
                return _root ? xml_node(_root->parent) : xml_node();
        }

        PUGI__FN xml_node xml_node::root() const
        {
                return _root ? xml_node(&impl::get_document(_root)) : xml_node();
        }

        PUGI__FN xml_text xml_node::text() const
        {
                return xml_text(_root);
        }

        PUGI__FN const char_t* xml_node::child_value() const
        {
                if (!_root) return PUGIXML_TEXT("");

                // element nodes can have value if parse_embed_pcdata was used
                if (PUGI__NODETYPE(_root) == node_element && _root->value)
                        return _root->value;

                for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
                        if (impl::is_text_node(i) && i->value)
                                return i->value;

                return PUGIXML_TEXT("");
        }

        PUGI__FN const char_t* xml_node::child_value(const char_t* name_) const
        {
                return child(name_).child_value();
        }

        PUGI__FN xml_attribute xml_node::first_attribute() const
        {
                return _root ? xml_attribute(_root->first_attribute) : xml_attribute();
        }

        PUGI__FN xml_attribute xml_node::last_attribute() const
        {
                return _root && _root->first_attribute ? xml_attribute(_root->first_attribute->prev_attribute_c) : xml_attribute();
        }

        PUGI__FN xml_node xml_node::first_child() const
        {
                return _root ? xml_node(_root->first_child) : xml_node();
        }

        PUGI__FN xml_node xml_node::last_child() const
        {
                return _root && _root->first_child ? xml_node(_root->first_child->prev_sibling_c) : xml_node();
        }

        PUGI__FN bool xml_node::set_name(const char_t* rhs)
        {
                xml_node_type type_ = _root ? PUGI__NODETYPE(_root) : node_null;

                if (type_ != node_element && type_ != node_pi && type_ != node_declaration)
                        return false;

                return impl::strcpy_insitu(_root->name, _root->header, impl::xml_memory_page_name_allocated_mask, rhs, impl::strlength(rhs));
        }

        PUGI__FN bool xml_node::set_value(const char_t* rhs)
        {
                xml_node_type type_ = _root ? PUGI__NODETYPE(_root) : node_null;

                if (type_ != node_pcdata && type_ != node_cdata && type_ != node_comment && type_ != node_pi && type_ != node_doctype)
                        return false;

                return impl::strcpy_insitu(_root->value, _root->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs));
        }

        PUGI__FN xml_attribute xml_node::append_attribute(const char_t* name_)
        {
                if (!impl::allow_insert_attribute(type())) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::append_attribute(a._attr, _root);

                a.set_name(name_);

                return a;
        }

        PUGI__FN xml_attribute xml_node::prepend_attribute(const char_t* name_)
        {
                if (!impl::allow_insert_attribute(type())) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::prepend_attribute(a._attr, _root);

                a.set_name(name_);

                return a;
        }

        PUGI__FN xml_attribute xml_node::insert_attribute_after(const char_t* name_, const xml_attribute& attr)
        {
                if (!impl::allow_insert_attribute(type())) return xml_attribute();
                if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::insert_attribute_after(a._attr, attr._attr, _root);

                a.set_name(name_);

                return a;
        }

        PUGI__FN xml_attribute xml_node::insert_attribute_before(const char_t* name_, const xml_attribute& attr)
        {
                if (!impl::allow_insert_attribute(type())) return xml_attribute();
                if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::insert_attribute_before(a._attr, attr._attr, _root);

                a.set_name(name_);

                return a;
        }

        PUGI__FN xml_attribute xml_node::append_copy(const xml_attribute& proto)
        {
                if (!proto) return xml_attribute();
                if (!impl::allow_insert_attribute(type())) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::append_attribute(a._attr, _root);
                impl::node_copy_attribute(a._attr, proto._attr);

                return a;
        }

        PUGI__FN xml_attribute xml_node::prepend_copy(const xml_attribute& proto)
        {
                if (!proto) return xml_attribute();
                if (!impl::allow_insert_attribute(type())) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::prepend_attribute(a._attr, _root);
                impl::node_copy_attribute(a._attr, proto._attr);

                return a;
        }

        PUGI__FN xml_attribute xml_node::insert_copy_after(const xml_attribute& proto, const xml_attribute& attr)
        {
                if (!proto) return xml_attribute();
                if (!impl::allow_insert_attribute(type())) return xml_attribute();
                if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::insert_attribute_after(a._attr, attr._attr, _root);
                impl::node_copy_attribute(a._attr, proto._attr);

                return a;
        }

        PUGI__FN xml_attribute xml_node::insert_copy_before(const xml_attribute& proto, const xml_attribute& attr)
        {
                if (!proto) return xml_attribute();
                if (!impl::allow_insert_attribute(type())) return xml_attribute();
                if (!attr || !impl::is_attribute_of(attr._attr, _root)) return xml_attribute();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_attribute();

                xml_attribute a(impl::allocate_attribute(alloc));
                if (!a) return xml_attribute();

                impl::insert_attribute_before(a._attr, attr._attr, _root);
                impl::node_copy_attribute(a._attr, proto._attr);

                return a;
        }

        PUGI__FN xml_node xml_node::append_child(xml_node_type type_)
        {
                if (!impl::allow_insert_child(type(), type_)) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::append_node(n._root, _root);

                if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

                return n;
        }

        PUGI__FN xml_node xml_node::prepend_child(xml_node_type type_)
        {
                if (!impl::allow_insert_child(type(), type_)) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::prepend_node(n._root, _root);

                if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

                return n;
        }

        PUGI__FN xml_node xml_node::insert_child_before(xml_node_type type_, const xml_node& node)
        {
                if (!impl::allow_insert_child(type(), type_)) return xml_node();
                if (!node._root || node._root->parent != _root) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::insert_node_before(n._root, node._root);

                if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

                return n;
        }

        PUGI__FN xml_node xml_node::insert_child_after(xml_node_type type_, const xml_node& node)
        {
                if (!impl::allow_insert_child(type(), type_)) return xml_node();
                if (!node._root || node._root->parent != _root) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::insert_node_after(n._root, node._root);

                if (type_ == node_declaration) n.set_name(PUGIXML_TEXT("xml"));

                return n;
        }

        PUGI__FN xml_node xml_node::append_child(const char_t* name_)
        {
                xml_node result = append_child(node_element);

                result.set_name(name_);

                return result;
        }

        PUGI__FN xml_node xml_node::prepend_child(const char_t* name_)
        {
                xml_node result = prepend_child(node_element);

                result.set_name(name_);

                return result;
        }

        PUGI__FN xml_node xml_node::insert_child_after(const char_t* name_, const xml_node& node)
        {
                xml_node result = insert_child_after(node_element, node);

                result.set_name(name_);

                return result;
        }

        PUGI__FN xml_node xml_node::insert_child_before(const char_t* name_, const xml_node& node)
        {
                xml_node result = insert_child_before(node_element, node);

                result.set_name(name_);

                return result;
        }

        PUGI__FN xml_node xml_node::append_copy(const xml_node& proto)
        {
                xml_node_type type_ = proto.type();
                if (!impl::allow_insert_child(type(), type_)) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::append_node(n._root, _root);
                impl::node_copy_tree(n._root, proto._root);

                return n;
        }

        PUGI__FN xml_node xml_node::prepend_copy(const xml_node& proto)
        {
                xml_node_type type_ = proto.type();
                if (!impl::allow_insert_child(type(), type_)) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::prepend_node(n._root, _root);
                impl::node_copy_tree(n._root, proto._root);

                return n;
        }

        PUGI__FN xml_node xml_node::insert_copy_after(const xml_node& proto, const xml_node& node)
        {
                xml_node_type type_ = proto.type();
                if (!impl::allow_insert_child(type(), type_)) return xml_node();
                if (!node._root || node._root->parent != _root) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::insert_node_after(n._root, node._root);
                impl::node_copy_tree(n._root, proto._root);

                return n;
        }

        PUGI__FN xml_node xml_node::insert_copy_before(const xml_node& proto, const xml_node& node)
        {
                xml_node_type type_ = proto.type();
                if (!impl::allow_insert_child(type(), type_)) return xml_node();
                if (!node._root || node._root->parent != _root) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                xml_node n(impl::allocate_node(alloc, type_));
                if (!n) return xml_node();

                impl::insert_node_before(n._root, node._root);
                impl::node_copy_tree(n._root, proto._root);

                return n;
        }

        PUGI__FN xml_node xml_node::append_move(const xml_node& moved)
        {
                if (!impl::allow_move(*this, moved)) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
                impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

                impl::remove_node(moved._root);
                impl::append_node(moved._root, _root);

                return moved;
        }

        PUGI__FN xml_node xml_node::prepend_move(const xml_node& moved)
        {
                if (!impl::allow_move(*this, moved)) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
                impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

                impl::remove_node(moved._root);
                impl::prepend_node(moved._root, _root);

                return moved;
        }

        PUGI__FN xml_node xml_node::insert_move_after(const xml_node& moved, const xml_node& node)
        {
                if (!impl::allow_move(*this, moved)) return xml_node();
                if (!node._root || node._root->parent != _root) return xml_node();
                if (moved._root == node._root) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
                impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

                impl::remove_node(moved._root);
                impl::insert_node_after(moved._root, node._root);

                return moved;
        }

        PUGI__FN xml_node xml_node::insert_move_before(const xml_node& moved, const xml_node& node)
        {
                if (!impl::allow_move(*this, moved)) return xml_node();
                if (!node._root || node._root->parent != _root) return xml_node();
                if (moved._root == node._root) return xml_node();

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return xml_node();

                // disable document_buffer_order optimization since moving nodes around changes document order without changing buffer pointers
                impl::get_document(_root).header |= impl::xml_memory_page_contents_shared_mask;

                impl::remove_node(moved._root);
                impl::insert_node_before(moved._root, node._root);

                return moved;
        }

        PUGI__FN bool xml_node::remove_attribute(const char_t* name_)
        {
                return remove_attribute(attribute(name_));
        }

        PUGI__FN bool xml_node::remove_attribute(const xml_attribute& a)
        {
                if (!_root || !a._attr) return false;
                if (!impl::is_attribute_of(a._attr, _root)) return false;

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return false;

                impl::remove_attribute(a._attr, _root);
                impl::destroy_attribute(a._attr, alloc);

                return true;
        }

        PUGI__FN bool xml_node::remove_child(const char_t* name_)
        {
                return remove_child(child(name_));
        }

        PUGI__FN bool xml_node::remove_child(const xml_node& n)
        {
                if (!_root || !n._root || n._root->parent != _root) return false;

                impl::xml_allocator& alloc = impl::get_allocator(_root);
                if (!alloc.reserve()) return false;

                impl::remove_node(n._root);
                impl::destroy_node(n._root, alloc);

                return true;
        }

        PUGI__FN xml_parse_result xml_node::append_buffer(const void* contents, size_t size, unsigned int options, xml_encoding encoding)
        {
                // append_buffer is only valid for elements/documents
                if (!impl::allow_insert_child(type(), node_element)) return impl::make_parse_result(status_append_invalid_root);

                // get document node
                impl::xml_document_struct* doc = &impl::get_document(_root);

                // disable document_buffer_order optimization since in a document with multiple buffers comparing buffer pointers does not make sense
                doc->header |= impl::xml_memory_page_contents_shared_mask;

                // get extra buffer element (we'll store the document fragment buffer there so that we can deallocate it later)
                impl::xml_memory_page* page = 0;
                impl::xml_extra_buffer* extra = static_cast<impl::xml_extra_buffer*>(doc->allocate_memory(sizeof(impl::xml_extra_buffer) + sizeof(void*), page));
                (void)page;

                if (!extra) return impl::make_parse_result(status_out_of_memory);

        #ifdef PUGIXML_COMPACT
                // align the memory block to a pointer boundary; this is required for compact mode where memory allocations are only 4b aligned
                // note that this requires up to sizeof(void*)-1 additional memory, which the allocation above takes into account
                extra = reinterpret_cast<impl::xml_extra_buffer*>((reinterpret_cast<uintptr_t>(extra) + (sizeof(void*) - 1)) & ~(sizeof(void*) - 1));
        #endif

                // add extra buffer to the list
                extra->buffer = 0;
                extra->next = doc->extra_buffers;
                doc->extra_buffers = extra;

                // name of the root has to be NULL before parsing - otherwise closing node mismatches will not be detected at the top level
                impl::name_null_sentry sentry(_root);

                return impl::load_buffer_impl(doc, _root, const_cast<void*>(contents), size, options, encoding, false, false, &extra->buffer);
        }

        PUGI__FN xml_node xml_node::find_child_by_attribute(const char_t* name_, const char_t* attr_name, const char_t* attr_value) const
        {
                if (!_root) return xml_node();

                for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
                        if (i->name && impl::strequal(name_, i->name))
                        {
                                for (xml_attribute_struct* a = i->first_attribute; a; a = a->next_attribute)
                                        if (a->name && impl::strequal(attr_name, a->name) && impl::strequal(attr_value, a->value ? a->value + 0 : PUGIXML_TEXT("")))
                                                return xml_node(i);
                        }

                return xml_node();
        }

        PUGI__FN xml_node xml_node::find_child_by_attribute(const char_t* attr_name, const char_t* attr_value) const
        {
                if (!_root) return xml_node();

                for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
                        for (xml_attribute_struct* a = i->first_attribute; a; a = a->next_attribute)
                                if (a->name && impl::strequal(attr_name, a->name) && impl::strequal(attr_value, a->value ? a->value + 0 : PUGIXML_TEXT("")))
                                        return xml_node(i);

                return xml_node();
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN string_t xml_node::path(char_t delimiter) const
        {
                if (!_root) return string_t();

                size_t offset = 0;

                for (xml_node_struct* i = _root; i; i = i->parent)
                {
                        offset += (i != _root);
                        offset += i->name ? impl::strlength(i->name) : 0;
                }

                string_t result;
                result.resize(offset);

                for (xml_node_struct* j = _root; j; j = j->parent)
                {
                        if (j != _root)
                                result[--offset] = delimiter;

                        if (j->name)
                        {
                                size_t length = impl::strlength(j->name);

                                offset -= length;
                                memcpy(&result[offset], j->name, length * sizeof(char_t));
                        }
                }

                assert(offset == 0);

                return result;
        }
#endif

        PUGI__FN xml_node xml_node::first_element_by_path(const char_t* path_, char_t delimiter) const
        {
                xml_node found = *this; // Current search context.

                if (!_root || !path_[0]) return found;

                if (path_[0] == delimiter)
                {
                        // Absolute path; e.g. '/foo/bar'
                        found = found.root();
                        ++path_;
                }

                const char_t* path_segment = path_;

                while (*path_segment == delimiter) ++path_segment;

                const char_t* path_segment_end = path_segment;

                while (*path_segment_end && *path_segment_end != delimiter) ++path_segment_end;

                if (path_segment == path_segment_end) return found;

                const char_t* next_segment = path_segment_end;

                while (*next_segment == delimiter) ++next_segment;

                if (*path_segment == '.' && path_segment + 1 == path_segment_end)
                        return found.first_element_by_path(next_segment, delimiter);
                else if (*path_segment == '.' && *(path_segment+1) == '.' && path_segment + 2 == path_segment_end)
                        return found.parent().first_element_by_path(next_segment, delimiter);
                else
                {
                        for (xml_node_struct* j = found._root->first_child; j; j = j->next_sibling)
                        {
                                if (j->name && impl::strequalrange(j->name, path_segment, static_cast<size_t>(path_segment_end - path_segment)))
                                {
                                        xml_node subsearch = xml_node(j).first_element_by_path(next_segment, delimiter);

                                        if (subsearch) return subsearch;
                                }
                        }

                        return xml_node();
                }
        }

        PUGI__FN bool xml_node::traverse(xml_tree_walker& walker)
        {
                walker._depth = -1;

                xml_node arg_begin(_root);
                if (!walker.begin(arg_begin)) return false;

                xml_node_struct* cur = _root ? _root->first_child + 0 : 0;

                if (cur)
                {
                        ++walker._depth;

                        do
                        {
                                xml_node arg_for_each(cur);
                                if (!walker.for_each(arg_for_each))
                                        return false;

                                if (cur->first_child)
                                {
                                        ++walker._depth;
                                        cur = cur->first_child;
                                }
                                else if (cur->next_sibling)
                                        cur = cur->next_sibling;
                                else
                                {
                                        while (!cur->next_sibling && cur != _root && cur->parent)
                                        {
                                                --walker._depth;
                                                cur = cur->parent;
                                        }

                                        if (cur != _root)
                                                cur = cur->next_sibling;
                                }
                        }
                        while (cur && cur != _root);
                }

                assert(walker._depth == -1);

                xml_node arg_end(_root);
                return walker.end(arg_end);
        }

        PUGI__FN size_t xml_node::hash_value() const
        {
                return static_cast<size_t>(reinterpret_cast<uintptr_t>(_root) / sizeof(xml_node_struct));
        }

        PUGI__FN xml_node_struct* xml_node::internal_object() const
        {
                return _root;
        }

        PUGI__FN void xml_node::print(xml_writer& writer, const char_t* indent, unsigned int flags, xml_encoding encoding, unsigned int depth) const
        {
                if (!_root) return;

                impl::xml_buffered_writer buffered_writer(writer, encoding);

                impl::node_output(buffered_writer, _root, indent, flags, depth);

                buffered_writer.flush();
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN void xml_node::print(std::basic_ostream<char, std::char_traits<char> >& stream, const char_t* indent, unsigned int flags, xml_encoding encoding, unsigned int depth) const
        {
                xml_writer_stream writer(stream);

                print(writer, indent, flags, encoding, depth);
        }

        PUGI__FN void xml_node::print(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream, const char_t* indent, unsigned int flags, unsigned int depth) const
        {
                xml_writer_stream writer(stream);

                print(writer, indent, flags, encoding_wchar, depth);
        }
#endif

        PUGI__FN ptrdiff_t xml_node::offset_debug() const
        {
                if (!_root) return -1;

                impl::xml_document_struct& doc = impl::get_document(_root);

                // we can determine the offset reliably only if there is exactly once parse buffer
                if (!doc.buffer || doc.extra_buffers) return -1;

                switch (type())
                {
                case node_document:
                        return 0;

                case node_element:
                case node_declaration:
                case node_pi:
                        return _root->name && (_root->header & impl::xml_memory_page_name_allocated_or_shared_mask) == 0 ? _root->name - doc.buffer : -1;

                case node_pcdata:
                case node_cdata:
                case node_comment:
                case node_doctype:
                        return _root->value && (_root->header & impl::xml_memory_page_value_allocated_or_shared_mask) == 0 ? _root->value - doc.buffer : -1;

                default:
                        assert(false && "Invalid node type"); // unreachable
                        return -1;
                }
        }

#ifdef __BORLANDC__
        PUGI__FN bool operator&&(const xml_node& lhs, bool rhs)
        {
                return (bool)lhs && rhs;
        }

        PUGI__FN bool operator||(const xml_node& lhs, bool rhs)
        {
                return (bool)lhs || rhs;
        }
#endif

        PUGI__FN xml_text::xml_text(xml_node_struct* root): _root(root)
        {
        }

        PUGI__FN xml_node_struct* xml_text::_data() const
        {
                if (!_root || impl::is_text_node(_root)) return _root;

                // element nodes can have value if parse_embed_pcdata was used
                if (PUGI__NODETYPE(_root) == node_element && _root->value)
                        return _root;

                for (xml_node_struct* node = _root->first_child; node; node = node->next_sibling)
                        if (impl::is_text_node(node))
                                return node;

                return 0;
        }

        PUGI__FN xml_node_struct* xml_text::_data_new()
        {
                xml_node_struct* d = _data();
                if (d) return d;

                return xml_node(_root).append_child(node_pcdata).internal_object();
        }

        PUGI__FN xml_text::xml_text(): _root(0)
        {
        }

        PUGI__FN static void unspecified_bool_xml_text(xml_text***)
        {
        }

        PUGI__FN xml_text::operator xml_text::unspecified_bool_type() const
        {
                return _data() ? unspecified_bool_xml_text : 0;
        }

        PUGI__FN bool xml_text::operator!() const
        {
                return !_data();
        }

        PUGI__FN bool xml_text::empty() const
        {
                return _data() == 0;
        }

        PUGI__FN const char_t* xml_text::get() const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? d->value + 0 : PUGIXML_TEXT("");
        }

        PUGI__FN const char_t* xml_text::as_string(const char_t* def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? d->value + 0 : def;
        }

        PUGI__FN int xml_text::as_int(int def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? impl::get_value_int(d->value) : def;
        }

        PUGI__FN unsigned int xml_text::as_uint(unsigned int def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? impl::get_value_uint(d->value) : def;
        }

        PUGI__FN double xml_text::as_double(double def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? impl::get_value_double(d->value) : def;
        }

        PUGI__FN float xml_text::as_float(float def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? impl::get_value_float(d->value) : def;
        }

        PUGI__FN bool xml_text::as_bool(bool def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? impl::get_value_bool(d->value) : def;
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN long long xml_text::as_llong(long long def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? impl::get_value_llong(d->value) : def;
        }

        PUGI__FN unsigned long long xml_text::as_ullong(unsigned long long def) const
        {
                xml_node_struct* d = _data();

                return (d && d->value) ? impl::get_value_ullong(d->value) : def;
        }
#endif

        PUGI__FN bool xml_text::set(const char_t* rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::strcpy_insitu(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, impl::strlength(rhs)) : false;
        }

        PUGI__FN bool xml_text::set(int rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_integer<unsigned int>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0) : false;
        }

        PUGI__FN bool xml_text::set(unsigned int rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_integer<unsigned int>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, false) : false;
        }

        PUGI__FN bool xml_text::set(long rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_integer<unsigned long>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0) : false;
        }

        PUGI__FN bool xml_text::set(unsigned long rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_integer<unsigned long>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, false) : false;
        }

        PUGI__FN bool xml_text::set(float rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_convert(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs) : false;
        }

        PUGI__FN bool xml_text::set(double rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_convert(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs) : false;
        }

        PUGI__FN bool xml_text::set(bool rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_bool(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs) : false;
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN bool xml_text::set(long long rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_integer<unsigned long long>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, rhs < 0) : false;
        }

        PUGI__FN bool xml_text::set(unsigned long long rhs)
        {
                xml_node_struct* dn = _data_new();

                return dn ? impl::set_value_integer<unsigned long long>(dn->value, dn->header, impl::xml_memory_page_value_allocated_mask, rhs, false) : false;
        }
#endif

        PUGI__FN xml_text& xml_text::operator=(const char_t* rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(int rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(unsigned int rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(long rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(unsigned long rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(double rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(float rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(bool rhs)
        {
                set(rhs);
                return *this;
        }

#ifdef PUGIXML_HAS_LONG_LONG
        PUGI__FN xml_text& xml_text::operator=(long long rhs)
        {
                set(rhs);
                return *this;
        }

        PUGI__FN xml_text& xml_text::operator=(unsigned long long rhs)
        {
                set(rhs);
                return *this;
        }
#endif

        PUGI__FN xml_node xml_text::data() const
        {
                return xml_node(_data());
        }

#ifdef __BORLANDC__
        PUGI__FN bool operator&&(const xml_text& lhs, bool rhs)
        {
                return (bool)lhs && rhs;
        }

        PUGI__FN bool operator||(const xml_text& lhs, bool rhs)
        {
                return (bool)lhs || rhs;
        }
#endif

        PUGI__FN xml_node_iterator::xml_node_iterator()
        {
        }

        PUGI__FN xml_node_iterator::xml_node_iterator(const xml_node& node): _wrap(node), _parent(node.parent())
        {
        }

        PUGI__FN xml_node_iterator::xml_node_iterator(xml_node_struct* ref, xml_node_struct* parent): _wrap(ref), _parent(parent)
        {
        }

        PUGI__FN bool xml_node_iterator::operator==(const xml_node_iterator& rhs) const
        {
                return _wrap._root == rhs._wrap._root && _parent._root == rhs._parent._root;
        }

        PUGI__FN bool xml_node_iterator::operator!=(const xml_node_iterator& rhs) const
        {
                return _wrap._root != rhs._wrap._root || _parent._root != rhs._parent._root;
        }

        PUGI__FN xml_node& xml_node_iterator::operator*() const
        {
                assert(_wrap._root);
                return _wrap;
        }

        PUGI__FN xml_node* xml_node_iterator::operator->() const
        {
                assert(_wrap._root);
                return const_cast<xml_node*>(&_wrap); // BCC5 workaround
        }

        PUGI__FN const xml_node_iterator& xml_node_iterator::operator++()
        {
                assert(_wrap._root);
                _wrap._root = _wrap._root->next_sibling;
                return *this;
        }

        PUGI__FN xml_node_iterator xml_node_iterator::operator++(int)
        {
                xml_node_iterator temp = *this;
                ++*this;
                return temp;
        }

        PUGI__FN const xml_node_iterator& xml_node_iterator::operator--()
        {
                _wrap = _wrap._root ? _wrap.previous_sibling() : _parent.last_child();
                return *this;
        }

        PUGI__FN xml_node_iterator xml_node_iterator::operator--(int)
        {
                xml_node_iterator temp = *this;
                --*this;
                return temp;
        }

        PUGI__FN xml_attribute_iterator::xml_attribute_iterator()
        {
        }

        PUGI__FN xml_attribute_iterator::xml_attribute_iterator(const xml_attribute& attr, const xml_node& parent): _wrap(attr), _parent(parent)
        {
        }

        PUGI__FN xml_attribute_iterator::xml_attribute_iterator(xml_attribute_struct* ref, xml_node_struct* parent): _wrap(ref), _parent(parent)
        {
        }

        PUGI__FN bool xml_attribute_iterator::operator==(const xml_attribute_iterator& rhs) const
        {
                return _wrap._attr == rhs._wrap._attr && _parent._root == rhs._parent._root;
        }

        PUGI__FN bool xml_attribute_iterator::operator!=(const xml_attribute_iterator& rhs) const
        {
                return _wrap._attr != rhs._wrap._attr || _parent._root != rhs._parent._root;
        }

        PUGI__FN xml_attribute& xml_attribute_iterator::operator*() const
        {
                assert(_wrap._attr);
                return _wrap;
        }

        PUGI__FN xml_attribute* xml_attribute_iterator::operator->() const
        {
                assert(_wrap._attr);
                return const_cast<xml_attribute*>(&_wrap); // BCC5 workaround
        }

        PUGI__FN const xml_attribute_iterator& xml_attribute_iterator::operator++()
        {
                assert(_wrap._attr);
                _wrap._attr = _wrap._attr->next_attribute;
                return *this;
        }

        PUGI__FN xml_attribute_iterator xml_attribute_iterator::operator++(int)
        {
                xml_attribute_iterator temp = *this;
                ++*this;
                return temp;
        }

        PUGI__FN const xml_attribute_iterator& xml_attribute_iterator::operator--()
        {
                _wrap = _wrap._attr ? _wrap.previous_attribute() : _parent.last_attribute();
                return *this;
        }

        PUGI__FN xml_attribute_iterator xml_attribute_iterator::operator--(int)
        {
                xml_attribute_iterator temp = *this;
                --*this;
                return temp;
        }

        PUGI__FN xml_named_node_iterator::xml_named_node_iterator(): _name(0)
        {
        }

        PUGI__FN xml_named_node_iterator::xml_named_node_iterator(const xml_node& node, const char_t* name): _wrap(node), _parent(node.parent()), _name(name)
        {
        }

        PUGI__FN xml_named_node_iterator::xml_named_node_iterator(xml_node_struct* ref, xml_node_struct* parent, const char_t* name): _wrap(ref), _parent(parent), _name(name)
        {
        }

        PUGI__FN bool xml_named_node_iterator::operator==(const xml_named_node_iterator& rhs) const
        {
                return _wrap._root == rhs._wrap._root && _parent._root == rhs._parent._root;
        }

        PUGI__FN bool xml_named_node_iterator::operator!=(const xml_named_node_iterator& rhs) const
        {
                return _wrap._root != rhs._wrap._root || _parent._root != rhs._parent._root;
        }

        PUGI__FN xml_node& xml_named_node_iterator::operator*() const
        {
                assert(_wrap._root);
                return _wrap;
        }

        PUGI__FN xml_node* xml_named_node_iterator::operator->() const
        {
                assert(_wrap._root);
                return const_cast<xml_node*>(&_wrap); // BCC5 workaround
        }

        PUGI__FN const xml_named_node_iterator& xml_named_node_iterator::operator++()
        {
                assert(_wrap._root);
                _wrap = _wrap.next_sibling(_name);
                return *this;
        }

        PUGI__FN xml_named_node_iterator xml_named_node_iterator::operator++(int)
        {
                xml_named_node_iterator temp = *this;
                ++*this;
                return temp;
        }

        PUGI__FN const xml_named_node_iterator& xml_named_node_iterator::operator--()
        {
                if (_wrap._root)
                        _wrap = _wrap.previous_sibling(_name);
                else
                {
                        _wrap = _parent.last_child();

                        if (!impl::strequal(_wrap.name(), _name))
                                _wrap = _wrap.previous_sibling(_name);
                }

                return *this;
        }

        PUGI__FN xml_named_node_iterator xml_named_node_iterator::operator--(int)
        {
                xml_named_node_iterator temp = *this;
                --*this;
                return temp;
        }

        PUGI__FN xml_parse_result::xml_parse_result(): status(status_internal_error), offset(0), encoding(encoding_auto)
        {
        }

        PUGI__FN xml_parse_result::operator bool() const
        {
                return status == status_ok;
        }

        PUGI__FN const char* xml_parse_result::description() const
        {
                switch (status)
                {
                case status_ok: return "No error";

                case status_file_not_found: return "File was not found";
                case status_io_error: return "Error reading from file/stream";
                case status_out_of_memory: return "Could not allocate memory";
                case status_internal_error: return "Internal error occurred";

                case status_unrecognized_tag: return "Could not determine tag type";

                case status_bad_pi: return "Error parsing document declaration/processing instruction";
                case status_bad_comment: return "Error parsing comment";
                case status_bad_cdata: return "Error parsing CDATA section";
                case status_bad_doctype: return "Error parsing document type declaration";
                case status_bad_pcdata: return "Error parsing PCDATA section";
                case status_bad_start_element: return "Error parsing start element tag";
                case status_bad_attribute: return "Error parsing element attribute";
                case status_bad_end_element: return "Error parsing end element tag";
                case status_end_element_mismatch: return "Start-end tags mismatch";

                case status_append_invalid_root: return "Unable to append nodes: root is not an element or document";

                case status_no_document_element: return "No document element found";

                default: return "Unknown error";
                }
        }

        PUGI__FN xml_document::xml_document(): _buffer(0)
        {
                _create();
        }

        PUGI__FN xml_document::~xml_document()
        {
                _destroy();
        }

#ifdef PUGIXML_HAS_MOVE
        PUGI__FN xml_document::xml_document(xml_document&& rhs) PUGIXML_NOEXCEPT_IF_NOT_COMPACT: _buffer(0)
        {
                _create();
                _move(rhs);
        }

        PUGI__FN xml_document& xml_document::operator=(xml_document&& rhs) PUGIXML_NOEXCEPT_IF_NOT_COMPACT
        {
                if (this == &rhs) return *this;

                _destroy();
                _create();
                _move(rhs);

                return *this;
        }
#endif

        PUGI__FN void xml_document::reset()
        {
                _destroy();
                _create();
        }

        PUGI__FN void xml_document::reset(const xml_document& proto)
        {
                reset();

                for (xml_node cur = proto.first_child(); cur; cur = cur.next_sibling())
                        append_copy(cur);
        }

        PUGI__FN void xml_document::_create()
        {
                assert(!_root);

        #ifdef PUGIXML_COMPACT
                // space for page marker for the first page (uint32_t), rounded up to pointer size; assumes pointers are at least 32-bit
                const size_t page_offset = sizeof(void*);
        #else
                const size_t page_offset = 0;
        #endif

                // initialize sentinel page
                PUGI__STATIC_ASSERT(sizeof(impl::xml_memory_page) + sizeof(impl::xml_document_struct) + page_offset <= sizeof(_memory));

                // prepare page structure
                impl::xml_memory_page* page = impl::xml_memory_page::construct(_memory);
                assert(page);

                page->busy_size = impl::xml_memory_page_size;

                // setup first page marker
        #ifdef PUGIXML_COMPACT
                // round-trip through void* to avoid 'cast increases required alignment of target type' warning
                page->compact_page_marker = reinterpret_cast<uint32_t*>(static_cast<void*>(reinterpret_cast<char*>(page) + sizeof(impl::xml_memory_page)));
                *page->compact_page_marker = sizeof(impl::xml_memory_page);
        #endif

                // allocate new root
                _root = new (reinterpret_cast<char*>(page) + sizeof(impl::xml_memory_page) + page_offset) impl::xml_document_struct(page);
                _root->prev_sibling_c = _root;

                // setup sentinel page
                page->allocator = static_cast<impl::xml_document_struct*>(_root);

                // setup hash table pointer in allocator
        #ifdef PUGIXML_COMPACT
                page->allocator->_hash = &static_cast<impl::xml_document_struct*>(_root)->hash;
        #endif

                // verify the document allocation
                assert(reinterpret_cast<char*>(_root) + sizeof(impl::xml_document_struct) <= _memory + sizeof(_memory));
        }

        PUGI__FN void xml_document::_destroy()
        {
                assert(_root);

                // destroy static storage
                if (_buffer)
                {
                        impl::xml_memory::deallocate(_buffer);
                        _buffer = 0;
                }

                // destroy extra buffers (note: no need to destroy linked list nodes, they're allocated using document allocator)
                for (impl::xml_extra_buffer* extra = static_cast<impl::xml_document_struct*>(_root)->extra_buffers; extra; extra = extra->next)
                {
                        if (extra->buffer) impl::xml_memory::deallocate(extra->buffer);
                }

                // destroy dynamic storage, leave sentinel page (it's in static memory)
                impl::xml_memory_page* root_page = PUGI__GETPAGE(_root);
                assert(root_page && !root_page->prev);
                assert(reinterpret_cast<char*>(root_page) >= _memory && reinterpret_cast<char*>(root_page) < _memory + sizeof(_memory));

                for (impl::xml_memory_page* page = root_page->next; page; )
                {
                        impl::xml_memory_page* next = page->next;

                        impl::xml_allocator::deallocate_page(page);

                        page = next;
                }

        #ifdef PUGIXML_COMPACT
                // destroy hash table
                static_cast<impl::xml_document_struct*>(_root)->hash.clear();
        #endif

                _root = 0;
        }

#ifdef PUGIXML_HAS_MOVE
        PUGI__FN void xml_document::_move(xml_document& rhs) PUGIXML_NOEXCEPT_IF_NOT_COMPACT
        {
                impl::xml_document_struct* doc = static_cast<impl::xml_document_struct*>(_root);
                impl::xml_document_struct* other = static_cast<impl::xml_document_struct*>(rhs._root);

                // save first child pointer for later; this needs hash access
                xml_node_struct* other_first_child = other->first_child;

        #ifdef PUGIXML_COMPACT
                // reserve space for the hash table up front; this is the only operation that can fail
                // if it does, we have no choice but to throw (if we have exceptions)
                if (other_first_child)
                {
                        size_t other_children = 0;
                        for (xml_node_struct* node = other_first_child; node; node = node->next_sibling)
                                other_children++;

                        // in compact mode, each pointer assignment could result in a hash table request
                        // during move, we have to relocate document first_child and parents of all children
                        // normally there's just one child and its parent has a pointerless encoding but
                        // we assume the worst here
                        if (!other->_hash->reserve(other_children + 1))
                        {
                        #ifdef PUGIXML_NO_EXCEPTIONS
                                return;
                        #else
                                throw std::bad_alloc();
                        #endif
                        }
                }
        #endif

                // move allocation state
                doc->_root = other->_root;
                doc->_busy_size = other->_busy_size;

                // move buffer state
                doc->buffer = other->buffer;
                doc->extra_buffers = other->extra_buffers;
                _buffer = rhs._buffer;

        #ifdef PUGIXML_COMPACT
                // move compact hash; note that the hash table can have pointers to other but they will be "inactive", similarly to nodes removed with remove_child
                doc->hash = other->hash;
                doc->_hash = &doc->hash;

                // make sure we don't access other hash up until the end when we reinitialize other document
                other->_hash = 0;
        #endif

                // move page structure
                impl::xml_memory_page* doc_page = PUGI__GETPAGE(doc);
                assert(doc_page && !doc_page->prev && !doc_page->next);

                impl::xml_memory_page* other_page = PUGI__GETPAGE(other);
                assert(other_page && !other_page->prev);

                // relink pages since root page is embedded into xml_document
                if (impl::xml_memory_page* page = other_page->next)
                {
                        assert(page->prev == other_page);

                        page->prev = doc_page;

                        doc_page->next = page;
                        other_page->next = 0;
                }

                // make sure pages point to the correct document state
                for (impl::xml_memory_page* page = doc_page->next; page; page = page->next)
                {
                        assert(page->allocator == other);

                        page->allocator = doc;

                #ifdef PUGIXML_COMPACT
                        // this automatically migrates most children between documents and prevents ->parent assignment from allocating
                        if (page->compact_shared_parent == other)
                                page->compact_shared_parent = doc;
                #endif
                }

                // move tree structure
                assert(!doc->first_child);

                doc->first_child = other_first_child;

                for (xml_node_struct* node = other_first_child; node; node = node->next_sibling)
                {
                #ifdef PUGIXML_COMPACT
                        // most children will have migrated when we reassigned compact_shared_parent
                        assert(node->parent == other || node->parent == doc);

                        node->parent = doc;
                #else
                        assert(node->parent == other);
                        node->parent = doc;
                #endif
                }

                // reset other document
                new (other) impl::xml_document_struct(PUGI__GETPAGE(other));
                rhs._buffer = 0;
        }
#endif

#ifndef PUGIXML_NO_STL
        PUGI__FN xml_parse_result xml_document::load(std::basic_istream<char, std::char_traits<char> >& stream, unsigned int options, xml_encoding encoding)
        {
                reset();

                return impl::load_stream_impl(static_cast<impl::xml_document_struct*>(_root), stream, options, encoding, &_buffer);
        }

        PUGI__FN xml_parse_result xml_document::load(std::basic_istream<wchar_t, std::char_traits<wchar_t> >& stream, unsigned int options)
        {
                reset();

                return impl::load_stream_impl(static_cast<impl::xml_document_struct*>(_root), stream, options, encoding_wchar, &_buffer);
        }
#endif

        PUGI__FN xml_parse_result xml_document::load_string(const char_t* contents, unsigned int options)
        {
                // Force native encoding (skip autodetection)
        #ifdef PUGIXML_WCHAR_MODE
                xml_encoding encoding = encoding_wchar;
        #else
                xml_encoding encoding = encoding_utf8;
        #endif

                return load_buffer(contents, impl::strlength(contents) * sizeof(char_t), options, encoding);
        }

        PUGI__FN xml_parse_result xml_document::load(const char_t* contents, unsigned int options)
        {
                return load_string(contents, options);
        }

        PUGI__FN xml_parse_result xml_document::load_file(const char* path_, unsigned int options, xml_encoding encoding)
        {
                reset();

                using impl::auto_deleter; // MSVC7 workaround
                auto_deleter<FILE> file(fopen(path_, "rb"), impl::close_file);

                return impl::load_file_impl(static_cast<impl::xml_document_struct*>(_root), file.data, options, encoding, &_buffer);
        }

        PUGI__FN xml_parse_result xml_document::load_file(const wchar_t* path_, unsigned int options, xml_encoding encoding)
        {
                reset();

                using impl::auto_deleter; // MSVC7 workaround
                auto_deleter<FILE> file(impl::open_file_wide(path_, L"rb"), impl::close_file);

                return impl::load_file_impl(static_cast<impl::xml_document_struct*>(_root), file.data, options, encoding, &_buffer);
        }

        PUGI__FN xml_parse_result xml_document::load_buffer(const void* contents, size_t size, unsigned int options, xml_encoding encoding)
        {
                reset();

                return impl::load_buffer_impl(static_cast<impl::xml_document_struct*>(_root), _root, const_cast<void*>(contents), size, options, encoding, false, false, &_buffer);
        }

        PUGI__FN xml_parse_result xml_document::load_buffer_inplace(void* contents, size_t size, unsigned int options, xml_encoding encoding)
        {
                reset();

                return impl::load_buffer_impl(static_cast<impl::xml_document_struct*>(_root), _root, contents, size, options, encoding, true, false, &_buffer);
        }

        PUGI__FN xml_parse_result xml_document::load_buffer_inplace_own(void* contents, size_t size, unsigned int options, xml_encoding encoding)
        {
                reset();

                return impl::load_buffer_impl(static_cast<impl::xml_document_struct*>(_root), _root, contents, size, options, encoding, true, true, &_buffer);
        }

        PUGI__FN void xml_document::save(xml_writer& writer, const char_t* indent, unsigned int flags, xml_encoding encoding) const
        {
                impl::xml_buffered_writer buffered_writer(writer, encoding);

                if ((flags & format_write_bom) && encoding != encoding_latin1)
                {
                        // BOM always represents the codepoint U+FEFF, so just write it in native encoding
                #ifdef PUGIXML_WCHAR_MODE
                        unsigned int bom = 0xfeff;
                        buffered_writer.write(static_cast<wchar_t>(bom));
                #else
                        buffered_writer.write('\xef', '\xbb', '\xbf');
                #endif
                }

                if (!(flags & format_no_declaration) && !impl::has_declaration(_root))
                {
                        buffered_writer.write_string(PUGIXML_TEXT("<?xml version=\"1.0\""));
                        if (encoding == encoding_latin1) buffered_writer.write_string(PUGIXML_TEXT(" encoding=\"ISO-8859-1\""));
                        buffered_writer.write('?', '>');
                        if (!(flags & format_raw)) buffered_writer.write('\n');
                }

                impl::node_output(buffered_writer, _root, indent, flags, 0);

                buffered_writer.flush();
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN void xml_document::save(std::basic_ostream<char, std::char_traits<char> >& stream, const char_t* indent, unsigned int flags, xml_encoding encoding) const
        {
                xml_writer_stream writer(stream);

                save(writer, indent, flags, encoding);
        }

        PUGI__FN void xml_document::save(std::basic_ostream<wchar_t, std::char_traits<wchar_t> >& stream, const char_t* indent, unsigned int flags) const
        {
                xml_writer_stream writer(stream);

                save(writer, indent, flags, encoding_wchar);
        }
#endif

        PUGI__FN bool xml_document::save_file(const char* path_, const char_t* indent, unsigned int flags, xml_encoding encoding) const
        {
                using impl::auto_deleter; // MSVC7 workaround
                auto_deleter<FILE> file(fopen(path_, (flags & format_save_file_text) ? "w" : "wb"), impl::close_file);

                return impl::save_file_impl(*this, file.data, indent, flags, encoding);
        }

        PUGI__FN bool xml_document::save_file(const wchar_t* path_, const char_t* indent, unsigned int flags, xml_encoding encoding) const
        {
                using impl::auto_deleter; // MSVC7 workaround
                auto_deleter<FILE> file(impl::open_file_wide(path_, (flags & format_save_file_text) ? L"w" : L"wb"), impl::close_file);

                return impl::save_file_impl(*this, file.data, indent, flags, encoding);
        }

        PUGI__FN xml_node xml_document::document_element() const
        {
                assert(_root);

                for (xml_node_struct* i = _root->first_child; i; i = i->next_sibling)
                        if (PUGI__NODETYPE(i) == node_element)
                                return xml_node(i);

                return xml_node();
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN std::string PUGIXML_FUNCTION as_utf8(const wchar_t* str)
        {
                assert(str);

                return impl::as_utf8_impl(str, impl::strlength_wide(str));
        }

        PUGI__FN std::string PUGIXML_FUNCTION as_utf8(const std::basic_string<wchar_t>& str)
        {
                return impl::as_utf8_impl(str.c_str(), str.size());
        }

        PUGI__FN std::basic_string<wchar_t> PUGIXML_FUNCTION as_wide(const char* str)
        {
                assert(str);

                return impl::as_wide_impl(str, strlen(str));
        }

        PUGI__FN std::basic_string<wchar_t> PUGIXML_FUNCTION as_wide(const std::string& str)
        {
                return impl::as_wide_impl(str.c_str(), str.size());
        }
#endif

        PUGI__FN void PUGIXML_FUNCTION set_memory_management_functions(allocation_function allocate, deallocation_function deallocate)
        {
                impl::xml_memory::allocate = allocate;
                impl::xml_memory::deallocate = deallocate;
        }

        PUGI__FN allocation_function PUGIXML_FUNCTION get_memory_allocation_function()
        {
                return impl::xml_memory::allocate;
        }

        PUGI__FN deallocation_function PUGIXML_FUNCTION get_memory_deallocation_function()
        {
                return impl::xml_memory::deallocate;
        }
}

#if !defined(PUGIXML_NO_STL) && (defined(_MSC_VER) || defined(__ICC))
namespace std
{
        // Workarounds for (non-standard) iterator category detection for older versions (MSVC7/IC8 and earlier)
        PUGI__FN std::bidirectional_iterator_tag _Iter_cat(const pugi::xml_node_iterator&)
        {
                return std::bidirectional_iterator_tag();
        }

        PUGI__FN std::bidirectional_iterator_tag _Iter_cat(const pugi::xml_attribute_iterator&)
        {
                return std::bidirectional_iterator_tag();
        }

        PUGI__FN std::bidirectional_iterator_tag _Iter_cat(const pugi::xml_named_node_iterator&)
        {
                return std::bidirectional_iterator_tag();
        }
}
#endif

#if !defined(PUGIXML_NO_STL) && defined(__SUNPRO_CC)
namespace std
{
        // Workarounds for (non-standard) iterator category detection
        PUGI__FN std::bidirectional_iterator_tag __iterator_category(const pugi::xml_node_iterator&)
        {
                return std::bidirectional_iterator_tag();
        }

        PUGI__FN std::bidirectional_iterator_tag __iterator_category(const pugi::xml_attribute_iterator&)
        {
                return std::bidirectional_iterator_tag();
        }

        PUGI__FN std::bidirectional_iterator_tag __iterator_category(const pugi::xml_named_node_iterator&)
        {
                return std::bidirectional_iterator_tag();
        }
}
#endif

#ifndef PUGIXML_NO_XPATH
// STL replacements
PUGI__NS_BEGIN
        struct equal_to
        {
                template <typename T> bool operator()(const T& lhs, const T& rhs) const
                {
                        return lhs == rhs;
                }
        };

        struct not_equal_to
        {
                template <typename T> bool operator()(const T& lhs, const T& rhs) const
                {
                        return lhs != rhs;
                }
        };

        struct less
        {
                template <typename T> bool operator()(const T& lhs, const T& rhs) const
                {
                        return lhs < rhs;
                }
        };

        struct less_equal
        {
                template <typename T> bool operator()(const T& lhs, const T& rhs) const
                {
                        return lhs <= rhs;
                }
        };

        template <typename T> void swap(T& lhs, T& rhs)
        {
                T temp = lhs;
                lhs = rhs;
                rhs = temp;
        }

        template <typename I, typename Pred> I min_element(I begin, I end, const Pred& pred)
        {
                I result = begin;

                for (I it = begin + 1; it != end; ++it)
                        if (pred(*it, *result))
                                result = it;

                return result;
        }

        template <typename I> void reverse(I begin, I end)
        {
                while (end - begin > 1) swap(*begin++, *--end);
        }

        template <typename I> I unique(I begin, I end)
        {
                // fast skip head
                while (end - begin > 1 && *begin != *(begin + 1)) begin++;

                if (begin == end) return begin;

                // last written element
                I write = begin++;

                // merge unique elements
                while (begin != end)
                {
                        if (*begin != *write)
                                *++write = *begin++;
                        else
                                begin++;
                }

                // past-the-end (write points to live element)
                return write + 1;
        }

        template <typename T, typename Pred> void insertion_sort(T* begin, T* end, const Pred& pred)
        {
                if (begin == end)
                        return;

                for (T* it = begin + 1; it != end; ++it)
                {
                        T val = *it;
                        T* hole = it;

                        // move hole backwards
                        while (hole > begin && pred(val, *(hole - 1)))
                        {
                                *hole = *(hole - 1);
                                hole--;
                        }

                        // fill hole with element
                        *hole = val;
                }
        }

        template <typename I, typename Pred> I median3(I first, I middle, I last, const Pred& pred)
        {
                if (pred(*middle, *first)) swap(middle, first);
                if (pred(*last, *middle)) swap(last, middle);
                if (pred(*middle, *first)) swap(middle, first);

                return middle;
        }

        template <typename T, typename Pred> void partition3(T* begin, T* end, T pivot, const Pred& pred, T** out_eqbeg, T** out_eqend)
        {
                // invariant: array is split into 4 groups: = < ? > (each variable denotes the boundary between the groups)
                T* eq = begin;
                T* lt = begin;
                T* gt = end;

                while (lt < gt)
                {
                        if (pred(*lt, pivot))
                                lt++;
                        else if (*lt == pivot)
                                swap(*eq++, *lt++);
                        else
                                swap(*lt, *--gt);
                }

                // we now have just 4 groups: = < >; move equal elements to the middle
                T* eqbeg = gt;

                for (T* it = begin; it != eq; ++it)
                        swap(*it, *--eqbeg);

                *out_eqbeg = eqbeg;
                *out_eqend = gt;
        }

        template <typename I, typename Pred> void sort(I begin, I end, const Pred& pred)
        {
                // sort large chunks
                while (end - begin > 16)
                {
                        // find median element
                        I middle = begin + (end - begin) / 2;
                        I median = median3(begin, middle, end - 1, pred);

                        // partition in three chunks (< = >)
                        I eqbeg, eqend;
                        partition3(begin, end, *median, pred, &eqbeg, &eqend);

                        // loop on larger half
                        if (eqbeg - begin > end - eqend)
                        {
                                sort(eqend, end, pred);
                                end = eqbeg;
                        }
                        else
                        {
                                sort(begin, eqbeg, pred);
                                begin = eqend;
                        }
                }

                // insertion sort small chunk
                insertion_sort(begin, end, pred);
        }
PUGI__NS_END

// Allocator used for AST and evaluation stacks
PUGI__NS_BEGIN
        static const size_t xpath_memory_page_size =
        #ifdef PUGIXML_MEMORY_XPATH_PAGE_SIZE
                PUGIXML_MEMORY_XPATH_PAGE_SIZE
        #else
                4096
        #endif
                ;

        static const uintptr_t xpath_memory_block_alignment = sizeof(double) > sizeof(void*) ? sizeof(double) : sizeof(void*);

        struct xpath_memory_block
        {
                xpath_memory_block* next;
                size_t capacity;

                union
                {
                        char data[xpath_memory_page_size];
                        double alignment;
                };
        };

        struct xpath_allocator
        {
                xpath_memory_block* _root;
                size_t _root_size;
                bool* _error;

                xpath_allocator(xpath_memory_block* root, bool* error = 0): _root(root), _root_size(0), _error(error)
                {
                }

                void* allocate(size_t size)
                {
                        // round size up to block alignment boundary
                        size = (size + xpath_memory_block_alignment - 1) & ~(xpath_memory_block_alignment - 1);

                        if (_root_size + size <= _root->capacity)
                        {
                                void* buf = &_root->data[0] + _root_size;
                                _root_size += size;
                                return buf;
                        }
                        else
                        {
                                // make sure we have at least 1/4th of the page free after allocation to satisfy subsequent allocation requests
                                size_t block_capacity_base = sizeof(_root->data);
                                size_t block_capacity_req = size + block_capacity_base / 4;
                                size_t block_capacity = (block_capacity_base > block_capacity_req) ? block_capacity_base : block_capacity_req;

                                size_t block_size = block_capacity + offsetof(xpath_memory_block, data);

                                xpath_memory_block* block = static_cast<xpath_memory_block*>(xml_memory::allocate(block_size));
                                if (!block)
                                {
                                        if (_error) *_error = true;
                                        return 0;
                                }

                                block->next = _root;
                                block->capacity = block_capacity;

                                _root = block;
                                _root_size = size;

                                return block->data;
                        }
                }

                void* reallocate(void* ptr, size_t old_size, size_t new_size)
                {
                        // round size up to block alignment boundary
                        old_size = (old_size + xpath_memory_block_alignment - 1) & ~(xpath_memory_block_alignment - 1);
                        new_size = (new_size + xpath_memory_block_alignment - 1) & ~(xpath_memory_block_alignment - 1);

                        // we can only reallocate the last object
                        assert(ptr == 0 || static_cast<char*>(ptr) + old_size == &_root->data[0] + _root_size);

                        // try to reallocate the object inplace
                        if (ptr && _root_size - old_size + new_size <= _root->capacity)
                        {
                                _root_size = _root_size - old_size + new_size;
                                return ptr;
                        }

                        // allocate a new block
                        void* result = allocate(new_size);
                        if (!result) return 0;

                        // we have a new block
                        if (ptr)
                        {
                                // copy old data (we only support growing)
                                assert(new_size >= old_size);
                                memcpy(result, ptr, old_size);

                                // free the previous page if it had no other objects
                                assert(_root->data == result);
                                assert(_root->next);

                                if (_root->next->data == ptr)
                                {
                                        // deallocate the whole page, unless it was the first one
                                        xpath_memory_block* next = _root->next->next;

                                        if (next)
                                        {
                                                xml_memory::deallocate(_root->next);
                                                _root->next = next;
                                        }
                                }
                        }

                        return result;
                }

                void revert(const xpath_allocator& state)
                {
                        // free all new pages
                        xpath_memory_block* cur = _root;

                        while (cur != state._root)
                        {
                                xpath_memory_block* next = cur->next;

                                xml_memory::deallocate(cur);

                                cur = next;
                        }

                        // restore state
                        _root = state._root;
                        _root_size = state._root_size;
                }

                void release()
                {
                        xpath_memory_block* cur = _root;
                        assert(cur);

                        while (cur->next)
                        {
                                xpath_memory_block* next = cur->next;

                                xml_memory::deallocate(cur);

                                cur = next;
                        }
                }
        };

        struct xpath_allocator_capture
        {
                xpath_allocator_capture(xpath_allocator* alloc): _target(alloc), _state(*alloc)
                {
                }

                ~xpath_allocator_capture()
                {
                        _target->revert(_state);
                }

                xpath_allocator* _target;
                xpath_allocator _state;
        };

        struct xpath_stack
        {
                xpath_allocator* result;
                xpath_allocator* temp;
        };

        struct xpath_stack_data
        {
                xpath_memory_block blocks[2];
                xpath_allocator result;
                xpath_allocator temp;
                xpath_stack stack;
                bool oom;

                xpath_stack_data(): result(blocks + 0, &oom), temp(blocks + 1, &oom), oom(false)
                {
                        blocks[0].next = blocks[1].next = 0;
                        blocks[0].capacity = blocks[1].capacity = sizeof(blocks[0].data);

                        stack.result = &result;
                        stack.temp = &temp;
                }

                ~xpath_stack_data()
                {
                        result.release();
                        temp.release();
                }
        };
PUGI__NS_END

// String class
PUGI__NS_BEGIN
        class xpath_string
        {
                const char_t* _buffer;
                bool _uses_heap;
                size_t _length_heap;

                static char_t* duplicate_string(const char_t* string, size_t length, xpath_allocator* alloc)
                {
                        char_t* result = static_cast<char_t*>(alloc->allocate((length + 1) * sizeof(char_t)));
                        if (!result) return 0;

                        memcpy(result, string, length * sizeof(char_t));
                        result[length] = 0;

                        return result;
                }

                xpath_string(const char_t* buffer, bool uses_heap_, size_t length_heap): _buffer(buffer), _uses_heap(uses_heap_), _length_heap(length_heap)
                {
                }

        public:
                static xpath_string from_const(const char_t* str)
                {
                        return xpath_string(str, false, 0);
                }

                static xpath_string from_heap_preallocated(const char_t* begin, const char_t* end)
                {
                        assert(begin <= end && *end == 0);

                        return xpath_string(begin, true, static_cast<size_t>(end - begin));
                }

                static xpath_string from_heap(const char_t* begin, const char_t* end, xpath_allocator* alloc)
                {
                        assert(begin <= end);

                        if (begin == end)
                                return xpath_string();

                        size_t length = static_cast<size_t>(end - begin);
                        const char_t* data = duplicate_string(begin, length, alloc);

                        return data ? xpath_string(data, true, length) : xpath_string();
                }

                xpath_string(): _buffer(PUGIXML_TEXT("")), _uses_heap(false), _length_heap(0)
                {
                }

                void append(const xpath_string& o, xpath_allocator* alloc)
                {
                        // skip empty sources
                        if (!*o._buffer) return;

                        // fast append for constant empty target and constant source
                        if (!*_buffer && !_uses_heap && !o._uses_heap)
                        {
                                _buffer = o._buffer;
                        }
                        else
                        {
                                // need to make heap copy
                                size_t target_length = length();
                                size_t source_length = o.length();
                                size_t result_length = target_length + source_length;

                                // allocate new buffer
                                char_t* result = static_cast<char_t*>(alloc->reallocate(_uses_heap ? const_cast<char_t*>(_buffer) : 0, (target_length + 1) * sizeof(char_t), (result_length + 1) * sizeof(char_t)));
                                if (!result) return;

                                // append first string to the new buffer in case there was no reallocation
                                if (!_uses_heap) memcpy(result, _buffer, target_length * sizeof(char_t));

                                // append second string to the new buffer
                                memcpy(result + target_length, o._buffer, source_length * sizeof(char_t));
                                result[result_length] = 0;

                                // finalize
                                _buffer = result;
                                _uses_heap = true;
                                _length_heap = result_length;
                        }
                }

                const char_t* c_str() const
                {
                        return _buffer;
                }

                size_t length() const
                {
                        return _uses_heap ? _length_heap : strlength(_buffer);
                }

                char_t* data(xpath_allocator* alloc)
                {
                        // make private heap copy
                        if (!_uses_heap)
                        {
                                size_t length_ = strlength(_buffer);
                                const char_t* data_ = duplicate_string(_buffer, length_, alloc);

                                if (!data_) return 0;

                                _buffer = data_;
                                _uses_heap = true;
                                _length_heap = length_;
                        }

                        return const_cast<char_t*>(_buffer);
                }

                bool empty() const
                {
                        return *_buffer == 0;
                }

                bool operator==(const xpath_string& o) const
                {
                        return strequal(_buffer, o._buffer);
                }

                bool operator!=(const xpath_string& o) const
                {
                        return !strequal(_buffer, o._buffer);
                }

                bool uses_heap() const
                {
                        return _uses_heap;
                }
        };
PUGI__NS_END

PUGI__NS_BEGIN
        PUGI__FN bool starts_with(const char_t* string, const char_t* pattern)
        {
                while (*pattern && *string == *pattern)
                {
                        string++;
                        pattern++;
                }

                return *pattern == 0;
        }

        PUGI__FN const char_t* find_char(const char_t* s, char_t c)
        {
        #ifdef PUGIXML_WCHAR_MODE
                return wcschr(s, c);
        #else
                return strchr(s, c);
        #endif
        }

        PUGI__FN const char_t* find_substring(const char_t* s, const char_t* p)
        {
        #ifdef PUGIXML_WCHAR_MODE
                // MSVC6 wcsstr bug workaround (if s is empty it always returns 0)
                return (*p == 0) ? s : wcsstr(s, p);
        #else
                return strstr(s, p);
        #endif
        }

        // Converts symbol to lower case, if it is an ASCII one
        PUGI__FN char_t tolower_ascii(char_t ch)
        {
                return static_cast<unsigned int>(ch - 'A') < 26 ? static_cast<char_t>(ch | ' ') : ch;
        }

        PUGI__FN xpath_string string_value(const xpath_node& na, xpath_allocator* alloc)
        {
                if (na.attribute())
                        return xpath_string::from_const(na.attribute().value());
                else
                {
                        xml_node n = na.node();

                        switch (n.type())
                        {
                        case node_pcdata:
                        case node_cdata:
                        case node_comment:
                        case node_pi:
                                return xpath_string::from_const(n.value());

                        case node_document:
                        case node_element:
                        {
                                xpath_string result;

                                // element nodes can have value if parse_embed_pcdata was used
                                if (n.value()[0])
                                        result.append(xpath_string::from_const(n.value()), alloc);

                                xml_node cur = n.first_child();

                                while (cur && cur != n)
                                {
                                        if (cur.type() == node_pcdata || cur.type() == node_cdata)
                                                result.append(xpath_string::from_const(cur.value()), alloc);

                                        if (cur.first_child())
                                                cur = cur.first_child();
                                        else if (cur.next_sibling())
                                                cur = cur.next_sibling();
                                        else
                                        {
                                                while (!cur.next_sibling() && cur != n)
                                                        cur = cur.parent();

                                                if (cur != n) cur = cur.next_sibling();
                                        }
                                }

                                return result;
                        }

                        default:
                                return xpath_string();
                        }
                }
        }

        PUGI__FN bool node_is_before_sibling(xml_node_struct* ln, xml_node_struct* rn)
        {
                assert(ln->parent == rn->parent);

                // there is no common ancestor (the shared parent is null), nodes are from different documents
                if (!ln->parent) return ln < rn;

                // determine sibling order
                xml_node_struct* ls = ln;
                xml_node_struct* rs = rn;

                while (ls && rs)
                {
                        if (ls == rn) return true;
                        if (rs == ln) return false;

                        ls = ls->next_sibling;
                        rs = rs->next_sibling;
                }

                // if rn sibling chain ended ln must be before rn
                return !rs;
        }

        PUGI__FN bool node_is_before(xml_node_struct* ln, xml_node_struct* rn)
        {
                // find common ancestor at the same depth, if any
                xml_node_struct* lp = ln;
                xml_node_struct* rp = rn;

                while (lp && rp && lp->parent != rp->parent)
                {
                        lp = lp->parent;
                        rp = rp->parent;
                }

                // parents are the same!
                if (lp && rp) return node_is_before_sibling(lp, rp);

                // nodes are at different depths, need to normalize heights
                bool left_higher = !lp;

                while (lp)
                {
                        lp = lp->parent;
                        ln = ln->parent;
                }

                while (rp)
                {
                        rp = rp->parent;
                        rn = rn->parent;
                }

                // one node is the ancestor of the other
                if (ln == rn) return left_higher;

                // find common ancestor... again
                while (ln->parent != rn->parent)
                {
                        ln = ln->parent;
                        rn = rn->parent;
                }

                return node_is_before_sibling(ln, rn);
        }

        PUGI__FN bool node_is_ancestor(xml_node_struct* parent, xml_node_struct* node)
        {
                while (node && node != parent) node = node->parent;

                return parent && node == parent;
        }

        PUGI__FN const void* document_buffer_order(const xpath_node& xnode)
        {
                xml_node_struct* node = xnode.node().internal_object();

                if (node)
                {
                        if ((get_document(node).header & xml_memory_page_contents_shared_mask) == 0)
                        {
                                if (node->name && (node->header & impl::xml_memory_page_name_allocated_or_shared_mask) == 0) return node->name;
                                if (node->value && (node->header & impl::xml_memory_page_value_allocated_or_shared_mask) == 0) return node->value;
                        }

                        return 0;
                }

                xml_attribute_struct* attr = xnode.attribute().internal_object();

                if (attr)
                {
                        if ((get_document(attr).header & xml_memory_page_contents_shared_mask) == 0)
                        {
                                if ((attr->header & impl::xml_memory_page_name_allocated_or_shared_mask) == 0) return attr->name;
                                if ((attr->header & impl::xml_memory_page_value_allocated_or_shared_mask) == 0) return attr->value;
                        }

                        return 0;
                }

                return 0;
        }

        struct document_order_comparator
        {
                bool operator()(const xpath_node& lhs, const xpath_node& rhs) const
                {
                        // optimized document order based check
                        const void* lo = document_buffer_order(lhs);
                        const void* ro = document_buffer_order(rhs);

                        if (lo && ro) return lo < ro;

                        // slow comparison
                        xml_node ln = lhs.node(), rn = rhs.node();

                        // compare attributes
                        if (lhs.attribute() && rhs.attribute())
                        {
                                // shared parent
                                if (lhs.parent() == rhs.parent())
                                {
                                        // determine sibling order
                                        for (xml_attribute a = lhs.attribute(); a; a = a.next_attribute())
                                                if (a == rhs.attribute())
                                                        return true;

                                        return false;
                                }

                                // compare attribute parents
                                ln = lhs.parent();
                                rn = rhs.parent();
                        }
                        else if (lhs.attribute())
                        {
                                // attributes go after the parent element
                                if (lhs.parent() == rhs.node()) return false;

                                ln = lhs.parent();
                        }
                        else if (rhs.attribute())
                        {
                                // attributes go after the parent element
                                if (rhs.parent() == lhs.node()) return true;

                                rn = rhs.parent();
                        }

                        if (ln == rn) return false;

                        if (!ln || !rn) return ln < rn;

                        return node_is_before(ln.internal_object(), rn.internal_object());
                }
        };

        struct duplicate_comparator
        {
                bool operator()(const xpath_node& lhs, const xpath_node& rhs) const
                {
                        if (lhs.attribute()) return rhs.attribute() ? lhs.attribute() < rhs.attribute() : true;
                        else return rhs.attribute() ? false : lhs.node() < rhs.node();
                }
        };

        PUGI__FN double gen_nan()
        {
        #if defined(__STDC_IEC_559__) || ((FLT_RADIX - 0 == 2) && (FLT_MAX_EXP - 0 == 128) && (FLT_MANT_DIG - 0 == 24))
                PUGI__STATIC_ASSERT(sizeof(float) == sizeof(uint32_t));
                typedef uint32_t UI; // BCC5 workaround
                union { float f; UI i; } u;
                u.i = 0x7fc00000;
                return u.f;
        #else
                // fallback
                const volatile double zero = 0.0;
                return zero / zero;
        #endif
        }

        PUGI__FN bool is_nan(double value)
        {
        #if defined(PUGI__MSVC_CRT_VERSION) || defined(__BORLANDC__)
                return !!_isnan(value);
        #elif defined(fpclassify) && defined(FP_NAN)
                return fpclassify(value) == FP_NAN;
        #else
                // fallback
                const volatile double v = value;
                return v != v;
        #endif
        }

        PUGI__FN const char_t* convert_number_to_string_special(double value)
        {
        #if defined(PUGI__MSVC_CRT_VERSION) || defined(__BORLANDC__)
                if (_finite(value)) return (value == 0) ? PUGIXML_TEXT("0") : 0;
                if (_isnan(value)) return PUGIXML_TEXT("NaN");
                return value > 0 ? PUGIXML_TEXT("Infinity") : PUGIXML_TEXT("-Infinity");
        #elif defined(fpclassify) && defined(FP_NAN) && defined(FP_INFINITE) && defined(FP_ZERO)
                switch (fpclassify(value))
                {
                case FP_NAN:
                        return PUGIXML_TEXT("NaN");

                case FP_INFINITE:
                        return value > 0 ? PUGIXML_TEXT("Infinity") : PUGIXML_TEXT("-Infinity");

                case FP_ZERO:
                        return PUGIXML_TEXT("0");

                default:
                        return 0;
                }
        #else
                // fallback
                const volatile double v = value;

                if (v == 0) return PUGIXML_TEXT("0");
                if (v != v) return PUGIXML_TEXT("NaN");
                if (v * 2 == v) return value > 0 ? PUGIXML_TEXT("Infinity") : PUGIXML_TEXT("-Infinity");
                return 0;
        #endif
        }

        PUGI__FN bool convert_number_to_boolean(double value)
        {
                return (value != 0 && !is_nan(value));
        }

        PUGI__FN void truncate_zeros(char* begin, char* end)
        {
                while (begin != end && end[-1] == '0') end--;

                *end = 0;
        }

        // gets mantissa digits in the form of 0.xxxxx with 0. implied and the exponent
#if defined(PUGI__MSVC_CRT_VERSION) && PUGI__MSVC_CRT_VERSION >= 1400 && !defined(_WIN32_WCE)
        PUGI__FN void convert_number_to_mantissa_exponent(double value, char (&buffer)[32], char** out_mantissa, int* out_exponent)
        {
                // get base values
                int sign, exponent;
                _ecvt_s(buffer, sizeof(buffer), value, DBL_DIG + 1, &exponent, &sign);

                // truncate redundant zeros
                truncate_zeros(buffer, buffer + strlen(buffer));

                // fill results
                *out_mantissa = buffer;
                *out_exponent = exponent;
        }
#else
        PUGI__FN void convert_number_to_mantissa_exponent(double value, char (&buffer)[32], char** out_mantissa, int* out_exponent)
        {
                // get a scientific notation value with IEEE DBL_DIG decimals
                PUGI__SNPRINTF(buffer, "%.*e", DBL_DIG, value);

                // get the exponent (possibly negative)
                char* exponent_string = strchr(buffer, 'e');
                assert(exponent_string);

                int exponent = atoi(exponent_string + 1);

                // extract mantissa string: skip sign
                char* mantissa = buffer[0] == '-' ? buffer + 1 : buffer;
                assert(mantissa[0] != '0' && mantissa[1] == '.');

                // divide mantissa by 10 to eliminate integer part
                mantissa[1] = mantissa[0];
                mantissa++;
                exponent++;

                // remove extra mantissa digits and zero-terminate mantissa
                truncate_zeros(mantissa, exponent_string);

                // fill results
                *out_mantissa = mantissa;
                *out_exponent = exponent;
        }
#endif

        PUGI__FN xpath_string convert_number_to_string(double value, xpath_allocator* alloc)
        {
                // try special number conversion
                const char_t* special = convert_number_to_string_special(value);
                if (special) return xpath_string::from_const(special);

                // get mantissa + exponent form
                char mantissa_buffer[32];

                char* mantissa;
                int exponent;
                convert_number_to_mantissa_exponent(value, mantissa_buffer, &mantissa, &exponent);

                // allocate a buffer of suitable length for the number
                size_t result_size = strlen(mantissa_buffer) + (exponent > 0 ? exponent : -exponent) + 4;
                char_t* result = static_cast<char_t*>(alloc->allocate(sizeof(char_t) * result_size));
                if (!result) return xpath_string();

                // make the number!
                char_t* s = result;

                // sign
                if (value < 0) *s++ = '-';

                // integer part
                if (exponent <= 0)
                {
                        *s++ = '0';
                }
                else
                {
                        while (exponent > 0)
                        {
                                assert(*mantissa == 0 || static_cast<unsigned int>(*mantissa - '0') <= 9);
                                *s++ = *mantissa ? *mantissa++ : '0';
                                exponent--;
                        }
                }

                // fractional part
                if (*mantissa)
                {
                        // decimal point
                        *s++ = '.';

                        // extra zeroes from negative exponent
                        while (exponent < 0)
                        {
                                *s++ = '0';
                                exponent++;
                        }

                        // extra mantissa digits
                        while (*mantissa)
                        {
                                assert(static_cast<unsigned int>(*mantissa - '0') <= 9);
                                *s++ = *mantissa++;
                        }
                }

                // zero-terminate
                assert(s < result + result_size);
                *s = 0;

                return xpath_string::from_heap_preallocated(result, s);
        }

        PUGI__FN bool check_string_to_number_format(const char_t* string)
        {
                // parse leading whitespace
                while (PUGI__IS_CHARTYPE(*string, ct_space)) ++string;

                // parse sign
                if (*string == '-') ++string;

                if (!*string) return false;

                // if there is no integer part, there should be a decimal part with at least one digit
                if (!PUGI__IS_CHARTYPEX(string[0], ctx_digit) && (string[0] != '.' || !PUGI__IS_CHARTYPEX(string[1], ctx_digit))) return false;

                // parse integer part
                while (PUGI__IS_CHARTYPEX(*string, ctx_digit)) ++string;

                // parse decimal part
                if (*string == '.')
                {
                        ++string;

                        while (PUGI__IS_CHARTYPEX(*string, ctx_digit)) ++string;
                }

                // parse trailing whitespace
                while (PUGI__IS_CHARTYPE(*string, ct_space)) ++string;

                return *string == 0;
        }

        PUGI__FN double convert_string_to_number(const char_t* string)
        {
                // check string format
                if (!check_string_to_number_format(string)) return gen_nan();

                // parse string
        #ifdef PUGIXML_WCHAR_MODE
                return wcstod(string, 0);
        #else
                return strtod(string, 0);
        #endif
        }

        PUGI__FN bool convert_string_to_number_scratch(char_t (&buffer)[32], const char_t* begin, const char_t* end, double* out_result)
        {
                size_t length = static_cast<size_t>(end - begin);
                char_t* scratch = buffer;

                if (length >= sizeof(buffer) / sizeof(buffer[0]))
                {
                        // need to make dummy on-heap copy
                        scratch = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                        if (!scratch) return false;
                }

                // copy string to zero-terminated buffer and perform conversion
                memcpy(scratch, begin, length * sizeof(char_t));
                scratch[length] = 0;

                *out_result = convert_string_to_number(scratch);

                // free dummy buffer
                if (scratch != buffer) xml_memory::deallocate(scratch);

                return true;
        }

        PUGI__FN double round_nearest(double value)
        {
                return floor(value + 0.5);
        }

        PUGI__FN double round_nearest_nzero(double value)
        {
                // same as round_nearest, but returns -0 for [-0.5, -0]
                // ceil is used to differentiate between +0 and -0 (we return -0 for [-0.5, -0] and +0 for +0)
                return (value >= -0.5 && value <= 0) ? ceil(value) : floor(value + 0.5);
        }

        PUGI__FN const char_t* qualified_name(const xpath_node& node)
        {
                return node.attribute() ? node.attribute().name() : node.node().name();
        }

        PUGI__FN const char_t* local_name(const xpath_node& node)
        {
                const char_t* name = qualified_name(node);
                const char_t* p = find_char(name, ':');

                return p ? p + 1 : name;
        }

        struct namespace_uri_predicate
        {
                const char_t* prefix;
                size_t prefix_length;

                namespace_uri_predicate(const char_t* name)
                {
                        const char_t* pos = find_char(name, ':');

                        prefix = pos ? name : 0;
                        prefix_length = pos ? static_cast<size_t>(pos - name) : 0;
                }

                bool operator()(xml_attribute a) const
                {
                        const char_t* name = a.name();

                        if (!starts_with(name, PUGIXML_TEXT("xmlns"))) return false;

                        return prefix ? name[5] == ':' && strequalrange(name + 6, prefix, prefix_length) : name[5] == 0;
                }
        };

        PUGI__FN const char_t* namespace_uri(xml_node node)
        {
                namespace_uri_predicate pred = node.name();

                xml_node p = node;

                while (p)
                {
                        xml_attribute a = p.find_attribute(pred);

                        if (a) return a.value();

                        p = p.parent();
                }

                return PUGIXML_TEXT("");
        }

        PUGI__FN const char_t* namespace_uri(xml_attribute attr, xml_node parent)
        {
                namespace_uri_predicate pred = attr.name();

                // Default namespace does not apply to attributes
                if (!pred.prefix) return PUGIXML_TEXT("");

                xml_node p = parent;

                while (p)
                {
                        xml_attribute a = p.find_attribute(pred);

                        if (a) return a.value();

                        p = p.parent();
                }

                return PUGIXML_TEXT("");
        }

        PUGI__FN const char_t* namespace_uri(const xpath_node& node)
        {
                return node.attribute() ? namespace_uri(node.attribute(), node.parent()) : namespace_uri(node.node());
        }

        PUGI__FN char_t* normalize_space(char_t* buffer)
        {
                char_t* write = buffer;

                for (char_t* it = buffer; *it; )
                {
                        char_t ch = *it++;

                        if (PUGI__IS_CHARTYPE(ch, ct_space))
                        {
                                // replace whitespace sequence with single space
                                while (PUGI__IS_CHARTYPE(*it, ct_space)) it++;

                                // avoid leading spaces
                                if (write != buffer) *write++ = ' ';
                        }
                        else *write++ = ch;
                }

                // remove trailing space
                if (write != buffer && PUGI__IS_CHARTYPE(write[-1], ct_space)) write--;

                // zero-terminate
                *write = 0;

                return write;
        }

        PUGI__FN char_t* translate(char_t* buffer, const char_t* from, const char_t* to, size_t to_length)
        {
                char_t* write = buffer;

                while (*buffer)
                {
                        PUGI__DMC_VOLATILE char_t ch = *buffer++;

                        const char_t* pos = find_char(from, ch);

                        if (!pos)
                                *write++ = ch; // do not process
                        else if (static_cast<size_t>(pos - from) < to_length)
                                *write++ = to[pos - from]; // replace
                }

                // zero-terminate
                *write = 0;

                return write;
        }

        PUGI__FN unsigned char* translate_table_generate(xpath_allocator* alloc, const char_t* from, const char_t* to)
        {
                unsigned char table[128] = {0};

                while (*from)
                {
                        unsigned int fc = static_cast<unsigned int>(*from);
                        unsigned int tc = static_cast<unsigned int>(*to);

                        if (fc >= 128 || tc >= 128)
                                return 0;

                        // code=128 means "skip character"
                        if (!table[fc])
                                table[fc] = static_cast<unsigned char>(tc ? tc : 128);

                        from++;
                        if (tc) to++;
                }

                for (int i = 0; i < 128; ++i)
                        if (!table[i])
                                table[i] = static_cast<unsigned char>(i);

                void* result = alloc->allocate(sizeof(table));
                if (!result) return 0;

                memcpy(result, table, sizeof(table));

                return static_cast<unsigned char*>(result);
        }

        PUGI__FN char_t* translate_table(char_t* buffer, const unsigned char* table)
        {
                char_t* write = buffer;

                while (*buffer)
                {
                        char_t ch = *buffer++;
                        unsigned int index = static_cast<unsigned int>(ch);

                        if (index < 128)
                        {
                                unsigned char code = table[index];

                                // code=128 means "skip character" (table size is 128 so 128 can be a special value)
                                // this code skips these characters without extra branches
                                *write = static_cast<char_t>(code);
                                write += 1 - (code >> 7);
                        }
                        else
                        {
                                *write++ = ch;
                        }
                }

                // zero-terminate
                *write = 0;

                return write;
        }

        inline bool is_xpath_attribute(const char_t* name)
        {
                return !(starts_with(name, PUGIXML_TEXT("xmlns")) && (name[5] == 0 || name[5] == ':'));
        }

        struct xpath_variable_boolean: xpath_variable
        {
                xpath_variable_boolean(): xpath_variable(xpath_type_boolean), value(false)
                {
                }

                bool value;
                char_t name[1];
        };

        struct xpath_variable_number: xpath_variable
        {
                xpath_variable_number(): xpath_variable(xpath_type_number), value(0)
                {
                }

                double value;
                char_t name[1];
        };

        struct xpath_variable_string: xpath_variable
        {
                xpath_variable_string(): xpath_variable(xpath_type_string), value(0)
                {
                }

                ~xpath_variable_string()
                {
                        if (value) xml_memory::deallocate(value);
                }

                char_t* value;
                char_t name[1];
        };

        struct xpath_variable_node_set: xpath_variable
        {
                xpath_variable_node_set(): xpath_variable(xpath_type_node_set)
                {
                }

                xpath_node_set value;
                char_t name[1];
        };

        static const xpath_node_set dummy_node_set;

        PUGI__FN PUGI__UNSIGNED_OVERFLOW unsigned int hash_string(const char_t* str)
        {
                // Jenkins one-at-a-time hash (http://en.wikipedia.org/wiki/Jenkins_hash_function#one-at-a-time)
                unsigned int result = 0;

                while (*str)
                {
                        result += static_cast<unsigned int>(*str++);
                        result += result << 10;
                        result ^= result >> 6;
                }

                result += result << 3;
                result ^= result >> 11;
                result += result << 15;

                return result;
        }

        template <typename T> PUGI__FN T* new_xpath_variable(const char_t* name)
        {
                size_t length = strlength(name);
                if (length == 0) return 0; // empty variable names are invalid

                // $$ we can't use offsetof(T, name) because T is non-POD, so we just allocate additional length characters
                void* memory = xml_memory::allocate(sizeof(T) + length * sizeof(char_t));
                if (!memory) return 0;

                T* result = new (memory) T();

                memcpy(result->name, name, (length + 1) * sizeof(char_t));

                return result;
        }

        PUGI__FN xpath_variable* new_xpath_variable(xpath_value_type type, const char_t* name)
        {
                switch (type)
                {
                case xpath_type_node_set:
                        return new_xpath_variable<xpath_variable_node_set>(name);

                case xpath_type_number:
                        return new_xpath_variable<xpath_variable_number>(name);

                case xpath_type_string:
                        return new_xpath_variable<xpath_variable_string>(name);

                case xpath_type_boolean:
                        return new_xpath_variable<xpath_variable_boolean>(name);

                default:
                        return 0;
                }
        }

        template <typename T> PUGI__FN void delete_xpath_variable(T* var)
        {
                var->~T();
                xml_memory::deallocate(var);
        }

        PUGI__FN void delete_xpath_variable(xpath_value_type type, xpath_variable* var)
        {
                switch (type)
                {
                case xpath_type_node_set:
                        delete_xpath_variable(static_cast<xpath_variable_node_set*>(var));
                        break;

                case xpath_type_number:
                        delete_xpath_variable(static_cast<xpath_variable_number*>(var));
                        break;

                case xpath_type_string:
                        delete_xpath_variable(static_cast<xpath_variable_string*>(var));
                        break;

                case xpath_type_boolean:
                        delete_xpath_variable(static_cast<xpath_variable_boolean*>(var));
                        break;

                default:
                        assert(false && "Invalid variable type"); // unreachable
                }
        }

        PUGI__FN bool copy_xpath_variable(xpath_variable* lhs, const xpath_variable* rhs)
        {
                switch (rhs->type())
                {
                case xpath_type_node_set:
                        return lhs->set(static_cast<const xpath_variable_node_set*>(rhs)->value);

                case xpath_type_number:
                        return lhs->set(static_cast<const xpath_variable_number*>(rhs)->value);

                case xpath_type_string:
                        return lhs->set(static_cast<const xpath_variable_string*>(rhs)->value);

                case xpath_type_boolean:
                        return lhs->set(static_cast<const xpath_variable_boolean*>(rhs)->value);

                default:
                        assert(false && "Invalid variable type"); // unreachable
                        return false;
                }
        }

        PUGI__FN bool get_variable_scratch(char_t (&buffer)[32], xpath_variable_set* set, const char_t* begin, const char_t* end, xpath_variable** out_result)
        {
                size_t length = static_cast<size_t>(end - begin);
                char_t* scratch = buffer;

                if (length >= sizeof(buffer) / sizeof(buffer[0]))
                {
                        // need to make dummy on-heap copy
                        scratch = static_cast<char_t*>(xml_memory::allocate((length + 1) * sizeof(char_t)));
                        if (!scratch) return false;
                }

                // copy string to zero-terminated buffer and perform lookup
                memcpy(scratch, begin, length * sizeof(char_t));
                scratch[length] = 0;

                *out_result = set->get(scratch);

                // free dummy buffer
                if (scratch != buffer) xml_memory::deallocate(scratch);

                return true;
        }
PUGI__NS_END

// Internal node set class
PUGI__NS_BEGIN
        PUGI__FN xpath_node_set::type_t xpath_get_order(const xpath_node* begin, const xpath_node* end)
        {
                if (end - begin < 2)
                        return xpath_node_set::type_sorted;

                document_order_comparator cmp;

                bool first = cmp(begin[0], begin[1]);

                for (const xpath_node* it = begin + 1; it + 1 < end; ++it)
                        if (cmp(it[0], it[1]) != first)
                                return xpath_node_set::type_unsorted;

                return first ? xpath_node_set::type_sorted : xpath_node_set::type_sorted_reverse;
        }

        PUGI__FN xpath_node_set::type_t xpath_sort(xpath_node* begin, xpath_node* end, xpath_node_set::type_t type, bool rev)
        {
                xpath_node_set::type_t order = rev ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_sorted;

                if (type == xpath_node_set::type_unsorted)
                {
                        xpath_node_set::type_t sorted = xpath_get_order(begin, end);

                        if (sorted == xpath_node_set::type_unsorted)
                        {
                                sort(begin, end, document_order_comparator());

                                type = xpath_node_set::type_sorted;
                        }
                        else
                                type = sorted;
                }

                if (type != order) reverse(begin, end);

                return order;
        }

        PUGI__FN xpath_node xpath_first(const xpath_node* begin, const xpath_node* end, xpath_node_set::type_t type)
        {
                if (begin == end) return xpath_node();

                switch (type)
                {
                case xpath_node_set::type_sorted:
                        return *begin;

                case xpath_node_set::type_sorted_reverse:
                        return *(end - 1);

                case xpath_node_set::type_unsorted:
                        return *min_element(begin, end, document_order_comparator());

                default:
                        assert(false && "Invalid node set type"); // unreachable
                        return xpath_node();
                }
        }

        class xpath_node_set_raw
        {
                xpath_node_set::type_t _type;

                xpath_node* _begin;
                xpath_node* _end;
                xpath_node* _eos;

        public:
                xpath_node_set_raw(): _type(xpath_node_set::type_unsorted), _begin(0), _end(0), _eos(0)
                {
                }

                xpath_node* begin() const
                {
                        return _begin;
                }

                xpath_node* end() const
                {
                        return _end;
                }

                bool empty() const
                {
                        return _begin == _end;
                }

                size_t size() const
                {
                        return static_cast<size_t>(_end - _begin);
                }

                xpath_node first() const
                {
                        return xpath_first(_begin, _end, _type);
                }

                void push_back_grow(const xpath_node& node, xpath_allocator* alloc);

                void push_back(const xpath_node& node, xpath_allocator* alloc)
                {
                        if (_end != _eos)
                                *_end++ = node;
                        else
                                push_back_grow(node, alloc);
                }

                void append(const xpath_node* begin_, const xpath_node* end_, xpath_allocator* alloc)
                {
                        if (begin_ == end_) return;

                        size_t size_ = static_cast<size_t>(_end - _begin);
                        size_t capacity = static_cast<size_t>(_eos - _begin);
                        size_t count = static_cast<size_t>(end_ - begin_);

                        if (size_ + count > capacity)
                        {
                                // reallocate the old array or allocate a new one
                                xpath_node* data = static_cast<xpath_node*>(alloc->reallocate(_begin, capacity * sizeof(xpath_node), (size_ + count) * sizeof(xpath_node)));
                                if (!data) return;

                                // finalize
                                _begin = data;
                                _end = data + size_;
                                _eos = data + size_ + count;
                        }

                        memcpy(_end, begin_, count * sizeof(xpath_node));
                        _end += count;
                }

                void sort_do()
                {
                        _type = xpath_sort(_begin, _end, _type, false);
                }

                void truncate(xpath_node* pos)
                {
                        assert(_begin <= pos && pos <= _end);

                        _end = pos;
                }

                void remove_duplicates()
                {
                        if (_type == xpath_node_set::type_unsorted)
                                sort(_begin, _end, duplicate_comparator());

                        _end = unique(_begin, _end);
                }

                xpath_node_set::type_t type() const
                {
                        return _type;
                }

                void set_type(xpath_node_set::type_t value)
                {
                        _type = value;
                }
        };

        PUGI__FN_NO_INLINE void xpath_node_set_raw::push_back_grow(const xpath_node& node, xpath_allocator* alloc)
        {
                size_t capacity = static_cast<size_t>(_eos - _begin);

                // get new capacity (1.5x rule)
                size_t new_capacity = capacity + capacity / 2 + 1;

                // reallocate the old array or allocate a new one
                xpath_node* data = static_cast<xpath_node*>(alloc->reallocate(_begin, capacity * sizeof(xpath_node), new_capacity * sizeof(xpath_node)));
                if (!data) return;

                // finalize
                _begin = data;
                _end = data + capacity;
                _eos = data + new_capacity;

                // push
                *_end++ = node;
        }
PUGI__NS_END

PUGI__NS_BEGIN
        struct xpath_context
        {
                xpath_node n;
                size_t position, size;

                xpath_context(const xpath_node& n_, size_t position_, size_t size_): n(n_), position(position_), size(size_)
                {
                }
        };

        enum lexeme_t
        {
                lex_none = 0,
                lex_equal,
                lex_not_equal,
                lex_less,
                lex_greater,
                lex_less_or_equal,
                lex_greater_or_equal,
                lex_plus,
                lex_minus,
                lex_multiply,
                lex_union,
                lex_var_ref,
                lex_open_brace,
                lex_close_brace,
                lex_quoted_string,
                lex_number,
                lex_slash,
                lex_double_slash,
                lex_open_square_brace,
                lex_close_square_brace,
                lex_string,
                lex_comma,
                lex_axis_attribute,
                lex_dot,
                lex_double_dot,
                lex_double_colon,
                lex_eof
        };

        struct xpath_lexer_string
        {
                const char_t* begin;
                const char_t* end;

                xpath_lexer_string(): begin(0), end(0)
                {
                }

                bool operator==(const char_t* other) const
                {
                        size_t length = static_cast<size_t>(end - begin);

                        return strequalrange(other, begin, length);
                }
        };

        class xpath_lexer
        {
                const char_t* _cur;
                const char_t* _cur_lexeme_pos;
                xpath_lexer_string _cur_lexeme_contents;

                lexeme_t _cur_lexeme;

        public:
                explicit xpath_lexer(const char_t* query): _cur(query)
                {
                        next();
                }

                const char_t* state() const
                {
                        return _cur;
                }

                void next()
                {
                        const char_t* cur = _cur;

                        while (PUGI__IS_CHARTYPE(*cur, ct_space)) ++cur;

                        // save lexeme position for error reporting
                        _cur_lexeme_pos = cur;

                        switch (*cur)
                        {
                        case 0:
                                _cur_lexeme = lex_eof;
                                break;

                        case '>':
                                if (*(cur+1) == '=')
                                {
                                        cur += 2;
                                        _cur_lexeme = lex_greater_or_equal;
                                }
                                else
                                {
                                        cur += 1;
                                        _cur_lexeme = lex_greater;
                                }
                                break;

                        case '<':
                                if (*(cur+1) == '=')
                                {
                                        cur += 2;
                                        _cur_lexeme = lex_less_or_equal;
                                }
                                else
                                {
                                        cur += 1;
                                        _cur_lexeme = lex_less;
                                }
                                break;

                        case '!':
                                if (*(cur+1) == '=')
                                {
                                        cur += 2;
                                        _cur_lexeme = lex_not_equal;
                                }
                                else
                                {
                                        _cur_lexeme = lex_none;
                                }
                                break;

                        case '=':
                                cur += 1;
                                _cur_lexeme = lex_equal;

                                break;

                        case '+':
                                cur += 1;
                                _cur_lexeme = lex_plus;

                                break;

                        case '-':
                                cur += 1;
                                _cur_lexeme = lex_minus;

                                break;

                        case '*':
                                cur += 1;
                                _cur_lexeme = lex_multiply;

                                break;

                        case '|':
                                cur += 1;
                                _cur_lexeme = lex_union;

                                break;

                        case '$':
                                cur += 1;

                                if (PUGI__IS_CHARTYPEX(*cur, ctx_start_symbol))
                                {
                                        _cur_lexeme_contents.begin = cur;

                                        while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;

                                        if (cur[0] == ':' && PUGI__IS_CHARTYPEX(cur[1], ctx_symbol)) // qname
                                        {
                                                cur++; // :

                                                while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;
                                        }

                                        _cur_lexeme_contents.end = cur;

                                        _cur_lexeme = lex_var_ref;
                                }
                                else
                                {
                                        _cur_lexeme = lex_none;
                                }

                                break;

                        case '(':
                                cur += 1;
                                _cur_lexeme = lex_open_brace;

                                break;

                        case ')':
                                cur += 1;
                                _cur_lexeme = lex_close_brace;

                                break;

                        case '[':
                                cur += 1;
                                _cur_lexeme = lex_open_square_brace;

                                break;

                        case ']':
                                cur += 1;
                                _cur_lexeme = lex_close_square_brace;

                                break;

                        case ',':
                                cur += 1;
                                _cur_lexeme = lex_comma;

                                break;

                        case '/':
                                if (*(cur+1) == '/')
                                {
                                        cur += 2;
                                        _cur_lexeme = lex_double_slash;
                                }
                                else
                                {
                                        cur += 1;
                                        _cur_lexeme = lex_slash;
                                }
                                break;

                        case '.':
                                if (*(cur+1) == '.')
                                {
                                        cur += 2;
                                        _cur_lexeme = lex_double_dot;
                                }
                                else if (PUGI__IS_CHARTYPEX(*(cur+1), ctx_digit))
                                {
                                        _cur_lexeme_contents.begin = cur; // .

                                        ++cur;

                                        while (PUGI__IS_CHARTYPEX(*cur, ctx_digit)) cur++;

                                        _cur_lexeme_contents.end = cur;

                                        _cur_lexeme = lex_number;
                                }
                                else
                                {
                                        cur += 1;
                                        _cur_lexeme = lex_dot;
                                }
                                break;

                        case '@':
                                cur += 1;
                                _cur_lexeme = lex_axis_attribute;

                                break;

                        case '"':
                        case '\'':
                        {
                                char_t terminator = *cur;

                                ++cur;

                                _cur_lexeme_contents.begin = cur;
                                while (*cur && *cur != terminator) cur++;
                                _cur_lexeme_contents.end = cur;

                                if (!*cur)
                                        _cur_lexeme = lex_none;
                                else
                                {
                                        cur += 1;
                                        _cur_lexeme = lex_quoted_string;
                                }

                                break;
                        }

                        case ':':
                                if (*(cur+1) == ':')
                                {
                                        cur += 2;
                                        _cur_lexeme = lex_double_colon;
                                }
                                else
                                {
                                        _cur_lexeme = lex_none;
                                }
                                break;

                        default:
                                if (PUGI__IS_CHARTYPEX(*cur, ctx_digit))
                                {
                                        _cur_lexeme_contents.begin = cur;

                                        while (PUGI__IS_CHARTYPEX(*cur, ctx_digit)) cur++;

                                        if (*cur == '.')
                                        {
                                                cur++;

                                                while (PUGI__IS_CHARTYPEX(*cur, ctx_digit)) cur++;
                                        }

                                        _cur_lexeme_contents.end = cur;

                                        _cur_lexeme = lex_number;
                                }
                                else if (PUGI__IS_CHARTYPEX(*cur, ctx_start_symbol))
                                {
                                        _cur_lexeme_contents.begin = cur;

                                        while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;

                                        if (cur[0] == ':')
                                        {
                                                if (cur[1] == '*') // namespace test ncname:*
                                                {
                                                        cur += 2; // :*
                                                }
                                                else if (PUGI__IS_CHARTYPEX(cur[1], ctx_symbol)) // namespace test qname
                                                {
                                                        cur++; // :

                                                        while (PUGI__IS_CHARTYPEX(*cur, ctx_symbol)) cur++;
                                                }
                                        }

                                        _cur_lexeme_contents.end = cur;

                                        _cur_lexeme = lex_string;
                                }
                                else
                                {
                                        _cur_lexeme = lex_none;
                                }
                        }

                        _cur = cur;
                }

                lexeme_t current() const
                {
                        return _cur_lexeme;
                }

                const char_t* current_pos() const
                {
                        return _cur_lexeme_pos;
                }

                const xpath_lexer_string& contents() const
                {
                        assert(_cur_lexeme == lex_var_ref || _cur_lexeme == lex_number || _cur_lexeme == lex_string || _cur_lexeme == lex_quoted_string);

                        return _cur_lexeme_contents;
                }
        };

        enum ast_type_t
        {
                ast_unknown,
                ast_op_or,                                              // left or right
                ast_op_and,                                             // left and right
                ast_op_equal,                                   // left = right
                ast_op_not_equal,                               // left != right
                ast_op_less,                                    // left < right
                ast_op_greater,                                 // left > right
                ast_op_less_or_equal,                   // left <= right
                ast_op_greater_or_equal,                // left >= right
                ast_op_add,                                             // left + right
                ast_op_subtract,                                // left - right
                ast_op_multiply,                                // left * right
                ast_op_divide,                                  // left / right
                ast_op_mod,                                             // left % right
                ast_op_negate,                                  // left - right
                ast_op_union,                                   // left | right
                ast_predicate,                                  // apply predicate to set; next points to next predicate
                ast_filter,                                             // select * from left where right
                ast_string_constant,                    // string constant
                ast_number_constant,                    // number constant
                ast_variable,                                   // variable
                ast_func_last,                                  // last()
                ast_func_position,                              // position()
                ast_func_count,                                 // count(left)
                ast_func_id,                                    // id(left)
                ast_func_local_name_0,                  // local-name()
                ast_func_local_name_1,                  // local-name(left)
                ast_func_namespace_uri_0,               // namespace-uri()
                ast_func_namespace_uri_1,               // namespace-uri(left)
                ast_func_name_0,                                // name()
                ast_func_name_1,                                // name(left)
                ast_func_string_0,                              // string()
                ast_func_string_1,                              // string(left)
                ast_func_concat,                                // concat(left, right, siblings)
                ast_func_starts_with,                   // starts_with(left, right)
                ast_func_contains,                              // contains(left, right)
                ast_func_substring_before,              // substring-before(left, right)
                ast_func_substring_after,               // substring-after(left, right)
                ast_func_substring_2,                   // substring(left, right)
                ast_func_substring_3,                   // substring(left, right, third)
                ast_func_string_length_0,               // string-length()
                ast_func_string_length_1,               // string-length(left)
                ast_func_normalize_space_0,             // normalize-space()
                ast_func_normalize_space_1,             // normalize-space(left)
                ast_func_translate,                             // translate(left, right, third)
                ast_func_boolean,                               // boolean(left)
                ast_func_not,                                   // not(left)
                ast_func_true,                                  // true()
                ast_func_false,                                 // false()
                ast_func_lang,                                  // lang(left)
                ast_func_number_0,                              // number()
                ast_func_number_1,                              // number(left)
                ast_func_sum,                                   // sum(left)
                ast_func_floor,                                 // floor(left)
                ast_func_ceiling,                               // ceiling(left)
                ast_func_round,                                 // round(left)
                ast_step,                                               // process set left with step
                ast_step_root,                                  // select root node

                ast_opt_translate_table,                // translate(left, right, third) where right/third are constants
                ast_opt_compare_attribute               // @name = 'string'
        };

        enum axis_t
        {
                axis_ancestor,
                axis_ancestor_or_self,
                axis_attribute,
                axis_child,
                axis_descendant,
                axis_descendant_or_self,
                axis_following,
                axis_following_sibling,
                axis_namespace,
                axis_parent,
                axis_preceding,
                axis_preceding_sibling,
                axis_self
        };

        enum nodetest_t
        {
                nodetest_none,
                nodetest_name,
                nodetest_type_node,
                nodetest_type_comment,
                nodetest_type_pi,
                nodetest_type_text,
                nodetest_pi,
                nodetest_all,
                nodetest_all_in_namespace
        };

        enum predicate_t
        {
                predicate_default,
                predicate_posinv,
                predicate_constant,
                predicate_constant_one
        };

        enum nodeset_eval_t
        {
                nodeset_eval_all,
                nodeset_eval_any,
                nodeset_eval_first
        };

        template <axis_t N> struct axis_to_type
        {
                static const axis_t axis;
        };

        template <axis_t N> const axis_t axis_to_type<N>::axis = N;

        class xpath_ast_node
        {
        private:
                // node type
                char _type;
                char _rettype;

                // for ast_step
                char _axis;

                // for ast_step/ast_predicate/ast_filter
                char _test;

                // tree node structure
                xpath_ast_node* _left;
                xpath_ast_node* _right;
                xpath_ast_node* _next;

                union
                {
                        // value for ast_string_constant
                        const char_t* string;
                        // value for ast_number_constant
                        double number;
                        // variable for ast_variable
                        xpath_variable* variable;
                        // node test for ast_step (node name/namespace/node type/pi target)
                        const char_t* nodetest;
                        // table for ast_opt_translate_table
                        const unsigned char* table;
                } _data;

                xpath_ast_node(const xpath_ast_node&);
                xpath_ast_node& operator=(const xpath_ast_node&);

                template <class Comp> static bool compare_eq(xpath_ast_node* lhs, xpath_ast_node* rhs, const xpath_context& c, const xpath_stack& stack, const Comp& comp)
                {
                        xpath_value_type lt = lhs->rettype(), rt = rhs->rettype();

                        if (lt != xpath_type_node_set && rt != xpath_type_node_set)
                        {
                                if (lt == xpath_type_boolean || rt == xpath_type_boolean)
                                        return comp(lhs->eval_boolean(c, stack), rhs->eval_boolean(c, stack));
                                else if (lt == xpath_type_number || rt == xpath_type_number)
                                        return comp(lhs->eval_number(c, stack), rhs->eval_number(c, stack));
                                else if (lt == xpath_type_string || rt == xpath_type_string)
                                {
                                        xpath_allocator_capture cr(stack.result);

                                        xpath_string ls = lhs->eval_string(c, stack);
                                        xpath_string rs = rhs->eval_string(c, stack);

                                        return comp(ls, rs);
                                }
                        }
                        else if (lt == xpath_type_node_set && rt == xpath_type_node_set)
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_node_set_raw ls = lhs->eval_node_set(c, stack, nodeset_eval_all);
                                xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

                                for (const xpath_node* li = ls.begin(); li != ls.end(); ++li)
                                        for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri)
                                        {
                                                xpath_allocator_capture cri(stack.result);

                                                if (comp(string_value(*li, stack.result), string_value(*ri, stack.result)))
                                                        return true;
                                        }

                                return false;
                        }
                        else
                        {
                                if (lt == xpath_type_node_set)
                                {
                                        swap(lhs, rhs);
                                        swap(lt, rt);
                                }

                                if (lt == xpath_type_boolean)
                                        return comp(lhs->eval_boolean(c, stack), rhs->eval_boolean(c, stack));
                                else if (lt == xpath_type_number)
                                {
                                        xpath_allocator_capture cr(stack.result);

                                        double l = lhs->eval_number(c, stack);
                                        xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

                                        for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri)
                                        {
                                                xpath_allocator_capture cri(stack.result);

                                                if (comp(l, convert_string_to_number(string_value(*ri, stack.result).c_str())))
                                                        return true;
                                        }

                                        return false;
                                }
                                else if (lt == xpath_type_string)
                                {
                                        xpath_allocator_capture cr(stack.result);

                                        xpath_string l = lhs->eval_string(c, stack);
                                        xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

                                        for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri)
                                        {
                                                xpath_allocator_capture cri(stack.result);

                                                if (comp(l, string_value(*ri, stack.result)))
                                                        return true;
                                        }

                                        return false;
                                }
                        }

                        assert(false && "Wrong types"); // unreachable
                        return false;
                }

                static bool eval_once(xpath_node_set::type_t type, nodeset_eval_t eval)
                {
                        return type == xpath_node_set::type_sorted ? eval != nodeset_eval_all : eval == nodeset_eval_any;
                }

                template <class Comp> static bool compare_rel(xpath_ast_node* lhs, xpath_ast_node* rhs, const xpath_context& c, const xpath_stack& stack, const Comp& comp)
                {
                        xpath_value_type lt = lhs->rettype(), rt = rhs->rettype();

                        if (lt != xpath_type_node_set && rt != xpath_type_node_set)
                                return comp(lhs->eval_number(c, stack), rhs->eval_number(c, stack));
                        else if (lt == xpath_type_node_set && rt == xpath_type_node_set)
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_node_set_raw ls = lhs->eval_node_set(c, stack, nodeset_eval_all);
                                xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

                                for (const xpath_node* li = ls.begin(); li != ls.end(); ++li)
                                {
                                        xpath_allocator_capture cri(stack.result);

                                        double l = convert_string_to_number(string_value(*li, stack.result).c_str());

                                        for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri)
                                        {
                                                xpath_allocator_capture crii(stack.result);

                                                if (comp(l, convert_string_to_number(string_value(*ri, stack.result).c_str())))
                                                        return true;
                                        }
                                }

                                return false;
                        }
                        else if (lt != xpath_type_node_set && rt == xpath_type_node_set)
                        {
                                xpath_allocator_capture cr(stack.result);

                                double l = lhs->eval_number(c, stack);
                                xpath_node_set_raw rs = rhs->eval_node_set(c, stack, nodeset_eval_all);

                                for (const xpath_node* ri = rs.begin(); ri != rs.end(); ++ri)
                                {
                                        xpath_allocator_capture cri(stack.result);

                                        if (comp(l, convert_string_to_number(string_value(*ri, stack.result).c_str())))
                                                return true;
                                }

                                return false;
                        }
                        else if (lt == xpath_type_node_set && rt != xpath_type_node_set)
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_node_set_raw ls = lhs->eval_node_set(c, stack, nodeset_eval_all);
                                double r = rhs->eval_number(c, stack);

                                for (const xpath_node* li = ls.begin(); li != ls.end(); ++li)
                                {
                                        xpath_allocator_capture cri(stack.result);

                                        if (comp(convert_string_to_number(string_value(*li, stack.result).c_str()), r))
                                                return true;
                                }

                                return false;
                        }
                        else
                        {
                                assert(false && "Wrong types"); // unreachable
                                return false;
                        }
                }

                static void apply_predicate_boolean(xpath_node_set_raw& ns, size_t first, xpath_ast_node* expr, const xpath_stack& stack, bool once)
                {
                        assert(ns.size() >= first);
                        assert(expr->rettype() != xpath_type_number);

                        size_t i = 1;
                        size_t size = ns.size() - first;

                        xpath_node* last = ns.begin() + first;

                        // remove_if... or well, sort of
                        for (xpath_node* it = last; it != ns.end(); ++it, ++i)
                        {
                                xpath_context c(*it, i, size);

                                if (expr->eval_boolean(c, stack))
                                {
                                        *last++ = *it;

                                        if (once) break;
                                }
                        }

                        ns.truncate(last);
                }

                static void apply_predicate_number(xpath_node_set_raw& ns, size_t first, xpath_ast_node* expr, const xpath_stack& stack, bool once)
                {
                        assert(ns.size() >= first);
                        assert(expr->rettype() == xpath_type_number);

                        size_t i = 1;
                        size_t size = ns.size() - first;

                        xpath_node* last = ns.begin() + first;

                        // remove_if... or well, sort of
                        for (xpath_node* it = last; it != ns.end(); ++it, ++i)
                        {
                                xpath_context c(*it, i, size);

                                if (expr->eval_number(c, stack) == i)
                                {
                                        *last++ = *it;

                                        if (once) break;
                                }
                        }

                        ns.truncate(last);
                }

                static void apply_predicate_number_const(xpath_node_set_raw& ns, size_t first, xpath_ast_node* expr, const xpath_stack& stack)
                {
                        assert(ns.size() >= first);
                        assert(expr->rettype() == xpath_type_number);

                        size_t size = ns.size() - first;

                        xpath_node* last = ns.begin() + first;

                        xpath_context c(xpath_node(), 1, size);

                        double er = expr->eval_number(c, stack);

                        if (er >= 1.0 && er <= size)
                        {
                                size_t eri = static_cast<size_t>(er);

                                if (er == eri)
                                {
                                        xpath_node r = last[eri - 1];

                                        *last++ = r;
                                }
                        }

                        ns.truncate(last);
                }

                void apply_predicate(xpath_node_set_raw& ns, size_t first, const xpath_stack& stack, bool once)
                {
                        if (ns.size() == first) return;

                        assert(_type == ast_filter || _type == ast_predicate);

                        if (_test == predicate_constant || _test == predicate_constant_one)
                                apply_predicate_number_const(ns, first, _right, stack);
                        else if (_right->rettype() == xpath_type_number)
                                apply_predicate_number(ns, first, _right, stack, once);
                        else
                                apply_predicate_boolean(ns, first, _right, stack, once);
                }

                void apply_predicates(xpath_node_set_raw& ns, size_t first, const xpath_stack& stack, nodeset_eval_t eval)
                {
                        if (ns.size() == first) return;

                        bool last_once = eval_once(ns.type(), eval);

                        for (xpath_ast_node* pred = _right; pred; pred = pred->_next)
                                pred->apply_predicate(ns, first, stack, !pred->_next && last_once);
                }

                bool step_push(xpath_node_set_raw& ns, xml_attribute_struct* a, xml_node_struct* parent, xpath_allocator* alloc)
                {
                        assert(a);

                        const char_t* name = a->name ? a->name + 0 : PUGIXML_TEXT("");

                        switch (_test)
                        {
                        case nodetest_name:
                                if (strequal(name, _data.nodetest) && is_xpath_attribute(name))
                                {
                                        ns.push_back(xpath_node(xml_attribute(a), xml_node(parent)), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_type_node:
                        case nodetest_all:
                                if (is_xpath_attribute(name))
                                {
                                        ns.push_back(xpath_node(xml_attribute(a), xml_node(parent)), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_all_in_namespace:
                                if (starts_with(name, _data.nodetest) && is_xpath_attribute(name))
                                {
                                        ns.push_back(xpath_node(xml_attribute(a), xml_node(parent)), alloc);
                                        return true;
                                }
                                break;

                        default:
                                ;
                        }

                        return false;
                }

                bool step_push(xpath_node_set_raw& ns, xml_node_struct* n, xpath_allocator* alloc)
                {
                        assert(n);

                        xml_node_type type = PUGI__NODETYPE(n);

                        switch (_test)
                        {
                        case nodetest_name:
                                if (type == node_element && n->name && strequal(n->name, _data.nodetest))
                                {
                                        ns.push_back(xml_node(n), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_type_node:
                                ns.push_back(xml_node(n), alloc);
                                return true;

                        case nodetest_type_comment:
                                if (type == node_comment)
                                {
                                        ns.push_back(xml_node(n), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_type_text:
                                if (type == node_pcdata || type == node_cdata)
                                {
                                        ns.push_back(xml_node(n), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_type_pi:
                                if (type == node_pi)
                                {
                                        ns.push_back(xml_node(n), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_pi:
                                if (type == node_pi && n->name && strequal(n->name, _data.nodetest))
                                {
                                        ns.push_back(xml_node(n), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_all:
                                if (type == node_element)
                                {
                                        ns.push_back(xml_node(n), alloc);
                                        return true;
                                }
                                break;

                        case nodetest_all_in_namespace:
                                if (type == node_element && n->name && starts_with(n->name, _data.nodetest))
                                {
                                        ns.push_back(xml_node(n), alloc);
                                        return true;
                                }
                                break;

                        default:
                                assert(false && "Unknown axis"); // unreachable
                        }

                        return false;
                }

                template <class T> void step_fill(xpath_node_set_raw& ns, xml_node_struct* n, xpath_allocator* alloc, bool once, T)
                {
                        const axis_t axis = T::axis;

                        switch (axis)
                        {
                        case axis_attribute:
                        {
                                for (xml_attribute_struct* a = n->first_attribute; a; a = a->next_attribute)
                                        if (step_push(ns, a, n, alloc) & once)
                                                return;

                                break;
                        }

                        case axis_child:
                        {
                                for (xml_node_struct* c = n->first_child; c; c = c->next_sibling)
                                        if (step_push(ns, c, alloc) & once)
                                                return;

                                break;
                        }

                        case axis_descendant:
                        case axis_descendant_or_self:
                        {
                                if (axis == axis_descendant_or_self)
                                        if (step_push(ns, n, alloc) & once)
                                                return;

                                xml_node_struct* cur = n->first_child;

                                while (cur)
                                {
                                        if (step_push(ns, cur, alloc) & once)
                                                return;

                                        if (cur->first_child)
                                                cur = cur->first_child;
                                        else
                                        {
                                                while (!cur->next_sibling)
                                                {
                                                        cur = cur->parent;

                                                        if (cur == n) return;
                                                }

                                                cur = cur->next_sibling;
                                        }
                                }

                                break;
                        }

                        case axis_following_sibling:
                        {
                                for (xml_node_struct* c = n->next_sibling; c; c = c->next_sibling)
                                        if (step_push(ns, c, alloc) & once)
                                                return;

                                break;
                        }

                        case axis_preceding_sibling:
                        {
                                for (xml_node_struct* c = n->prev_sibling_c; c->next_sibling; c = c->prev_sibling_c)
                                        if (step_push(ns, c, alloc) & once)
                                                return;

                                break;
                        }

                        case axis_following:
                        {
                                xml_node_struct* cur = n;

                                // exit from this node so that we don't include descendants
                                while (!cur->next_sibling)
                                {
                                        cur = cur->parent;

                                        if (!cur) return;
                                }

                                cur = cur->next_sibling;

                                while (cur)
                                {
                                        if (step_push(ns, cur, alloc) & once)
                                                return;

                                        if (cur->first_child)
                                                cur = cur->first_child;
                                        else
                                        {
                                                while (!cur->next_sibling)
                                                {
                                                        cur = cur->parent;

                                                        if (!cur) return;
                                                }

                                                cur = cur->next_sibling;
                                        }
                                }

                                break;
                        }

                        case axis_preceding:
                        {
                                xml_node_struct* cur = n;

                                // exit from this node so that we don't include descendants
                                while (!cur->prev_sibling_c->next_sibling)
                                {
                                        cur = cur->parent;

                                        if (!cur) return;
                                }

                                cur = cur->prev_sibling_c;

                                while (cur)
                                {
                                        if (cur->first_child)
                                                cur = cur->first_child->prev_sibling_c;
                                        else
                                        {
                                                // leaf node, can't be ancestor
                                                if (step_push(ns, cur, alloc) & once)
                                                        return;

                                                while (!cur->prev_sibling_c->next_sibling)
                                                {
                                                        cur = cur->parent;

                                                        if (!cur) return;

                                                        if (!node_is_ancestor(cur, n))
                                                                if (step_push(ns, cur, alloc) & once)
                                                                        return;
                                                }

                                                cur = cur->prev_sibling_c;
                                        }
                                }

                                break;
                        }

                        case axis_ancestor:
                        case axis_ancestor_or_self:
                        {
                                if (axis == axis_ancestor_or_self)
                                        if (step_push(ns, n, alloc) & once)
                                                return;

                                xml_node_struct* cur = n->parent;

                                while (cur)
                                {
                                        if (step_push(ns, cur, alloc) & once)
                                                return;

                                        cur = cur->parent;
                                }

                                break;
                        }

                        case axis_self:
                        {
                                step_push(ns, n, alloc);

                                break;
                        }

                        case axis_parent:
                        {
                                if (n->parent)
                                        step_push(ns, n->parent, alloc);

                                break;
                        }

                        default:
                                assert(false && "Unimplemented axis"); // unreachable
                        }
                }

                template <class T> void step_fill(xpath_node_set_raw& ns, xml_attribute_struct* a, xml_node_struct* p, xpath_allocator* alloc, bool once, T v)
                {
                        const axis_t axis = T::axis;

                        switch (axis)
                        {
                        case axis_ancestor:
                        case axis_ancestor_or_self:
                        {
                                if (axis == axis_ancestor_or_self && _test == nodetest_type_node) // reject attributes based on principal node type test
                                        if (step_push(ns, a, p, alloc) & once)
                                                return;

                                xml_node_struct* cur = p;

                                while (cur)
                                {
                                        if (step_push(ns, cur, alloc) & once)
                                                return;

                                        cur = cur->parent;
                                }

                                break;
                        }

                        case axis_descendant_or_self:
                        case axis_self:
                        {
                                if (_test == nodetest_type_node) // reject attributes based on principal node type test
                                        step_push(ns, a, p, alloc);

                                break;
                        }

                        case axis_following:
                        {
                                xml_node_struct* cur = p;

                                while (cur)
                                {
                                        if (cur->first_child)
                                                cur = cur->first_child;
                                        else
                                        {
                                                while (!cur->next_sibling)
                                                {
                                                        cur = cur->parent;

                                                        if (!cur) return;
                                                }

                                                cur = cur->next_sibling;
                                        }

                                        if (step_push(ns, cur, alloc) & once)
                                                return;
                                }

                                break;
                        }

                        case axis_parent:
                        {
                                step_push(ns, p, alloc);

                                break;
                        }

                        case axis_preceding:
                        {
                                // preceding:: axis does not include attribute nodes and attribute ancestors (they are the same as parent's ancestors), so we can reuse node preceding
                                step_fill(ns, p, alloc, once, v);
                                break;
                        }

                        default:
                                assert(false && "Unimplemented axis"); // unreachable
                        }
                }

                template <class T> void step_fill(xpath_node_set_raw& ns, const xpath_node& xn, xpath_allocator* alloc, bool once, T v)
                {
                        const axis_t axis = T::axis;
                        const bool axis_has_attributes = (axis == axis_ancestor || axis == axis_ancestor_or_self || axis == axis_descendant_or_self || axis == axis_following || axis == axis_parent || axis == axis_preceding || axis == axis_self);

                        if (xn.node())
                                step_fill(ns, xn.node().internal_object(), alloc, once, v);
                        else if (axis_has_attributes && xn.attribute() && xn.parent())
                                step_fill(ns, xn.attribute().internal_object(), xn.parent().internal_object(), alloc, once, v);
                }

                template <class T> xpath_node_set_raw step_do(const xpath_context& c, const xpath_stack& stack, nodeset_eval_t eval, T v)
                {
                        const axis_t axis = T::axis;
                        const bool axis_reverse = (axis == axis_ancestor || axis == axis_ancestor_or_self || axis == axis_preceding || axis == axis_preceding_sibling);
                        const xpath_node_set::type_t axis_type = axis_reverse ? xpath_node_set::type_sorted_reverse : xpath_node_set::type_sorted;

                        bool once =
                                (axis == axis_attribute && _test == nodetest_name) ||
                                (!_right && eval_once(axis_type, eval)) ||
                                (_right && !_right->_next && _right->_test == predicate_constant_one);

                        xpath_node_set_raw ns;
                        ns.set_type(axis_type);

                        if (_left)
                        {
                                xpath_node_set_raw s = _left->eval_node_set(c, stack, nodeset_eval_all);

                                // self axis preserves the original order
                                if (axis == axis_self) ns.set_type(s.type());

                                for (const xpath_node* it = s.begin(); it != s.end(); ++it)
                                {
                                        size_t size = ns.size();

                                        // in general, all axes generate elements in a particular order, but there is no order guarantee if axis is applied to two nodes
                                        if (axis != axis_self && size != 0) ns.set_type(xpath_node_set::type_unsorted);

                                        step_fill(ns, *it, stack.result, once, v);
                                        if (_right) apply_predicates(ns, size, stack, eval);
                                }
                        }
                        else
                        {
                                step_fill(ns, c.n, stack.result, once, v);
                                if (_right) apply_predicates(ns, 0, stack, eval);
                        }

                        // child, attribute and self axes always generate unique set of nodes
                        // for other axis, if the set stayed sorted, it stayed unique because the traversal algorithms do not visit the same node twice
                        if (axis != axis_child && axis != axis_attribute && axis != axis_self && ns.type() == xpath_node_set::type_unsorted)
                                ns.remove_duplicates();

                        return ns;
                }

        public:
                xpath_ast_node(ast_type_t type, xpath_value_type rettype_, const char_t* value):
                        _type(static_cast<char>(type)), _rettype(static_cast<char>(rettype_)), _axis(0), _test(0), _left(0), _right(0), _next(0)
                {
                        assert(type == ast_string_constant);
                        _data.string = value;
                }

                xpath_ast_node(ast_type_t type, xpath_value_type rettype_, double value):
                        _type(static_cast<char>(type)), _rettype(static_cast<char>(rettype_)), _axis(0), _test(0), _left(0), _right(0), _next(0)
                {
                        assert(type == ast_number_constant);
                        _data.number = value;
                }

                xpath_ast_node(ast_type_t type, xpath_value_type rettype_, xpath_variable* value):
                        _type(static_cast<char>(type)), _rettype(static_cast<char>(rettype_)), _axis(0), _test(0), _left(0), _right(0), _next(0)
                {
                        assert(type == ast_variable);
                        _data.variable = value;
                }

                xpath_ast_node(ast_type_t type, xpath_value_type rettype_, xpath_ast_node* left = 0, xpath_ast_node* right = 0):
                        _type(static_cast<char>(type)), _rettype(static_cast<char>(rettype_)), _axis(0), _test(0), _left(left), _right(right), _next(0)
                {
                }

                xpath_ast_node(ast_type_t type, xpath_ast_node* left, axis_t axis, nodetest_t test, const char_t* contents):
                        _type(static_cast<char>(type)), _rettype(xpath_type_node_set), _axis(static_cast<char>(axis)), _test(static_cast<char>(test)), _left(left), _right(0), _next(0)
                {
                        assert(type == ast_step);
                        _data.nodetest = contents;
                }

                xpath_ast_node(ast_type_t type, xpath_ast_node* left, xpath_ast_node* right, predicate_t test):
                        _type(static_cast<char>(type)), _rettype(xpath_type_node_set), _axis(0), _test(static_cast<char>(test)), _left(left), _right(right), _next(0)
                {
                        assert(type == ast_filter || type == ast_predicate);
                }

                void set_next(xpath_ast_node* value)
                {
                        _next = value;
                }

                void set_right(xpath_ast_node* value)
                {
                        _right = value;
                }

                bool eval_boolean(const xpath_context& c, const xpath_stack& stack)
                {
                        switch (_type)
                        {
                        case ast_op_or:
                                return _left->eval_boolean(c, stack) || _right->eval_boolean(c, stack);

                        case ast_op_and:
                                return _left->eval_boolean(c, stack) && _right->eval_boolean(c, stack);

                        case ast_op_equal:
                                return compare_eq(_left, _right, c, stack, equal_to());

                        case ast_op_not_equal:
                                return compare_eq(_left, _right, c, stack, not_equal_to());

                        case ast_op_less:
                                return compare_rel(_left, _right, c, stack, less());

                        case ast_op_greater:
                                return compare_rel(_right, _left, c, stack, less());

                        case ast_op_less_or_equal:
                                return compare_rel(_left, _right, c, stack, less_equal());

                        case ast_op_greater_or_equal:
                                return compare_rel(_right, _left, c, stack, less_equal());

                        case ast_func_starts_with:
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_string lr = _left->eval_string(c, stack);
                                xpath_string rr = _right->eval_string(c, stack);

                                return starts_with(lr.c_str(), rr.c_str());
                        }

                        case ast_func_contains:
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_string lr = _left->eval_string(c, stack);
                                xpath_string rr = _right->eval_string(c, stack);

                                return find_substring(lr.c_str(), rr.c_str()) != 0;
                        }

                        case ast_func_boolean:
                                return _left->eval_boolean(c, stack);

                        case ast_func_not:
                                return !_left->eval_boolean(c, stack);

                        case ast_func_true:
                                return true;

                        case ast_func_false:
                                return false;

                        case ast_func_lang:
                        {
                                if (c.n.attribute()) return false;

                                xpath_allocator_capture cr(stack.result);

                                xpath_string lang = _left->eval_string(c, stack);

                                for (xml_node n = c.n.node(); n; n = n.parent())
                                {
                                        xml_attribute a = n.attribute(PUGIXML_TEXT("xml:lang"));

                                        if (a)
                                        {
                                                const char_t* value = a.value();

                                                // strnicmp / strncasecmp is not portable
                                                for (const char_t* lit = lang.c_str(); *lit; ++lit)
                                                {
                                                        if (tolower_ascii(*lit) != tolower_ascii(*value)) return false;
                                                        ++value;
                                                }

                                                return *value == 0 || *value == '-';
                                        }
                                }

                                return false;
                        }

                        case ast_opt_compare_attribute:
                        {
                                const char_t* value = (_right->_type == ast_string_constant) ? _right->_data.string : _right->_data.variable->get_string();

                                xml_attribute attr = c.n.node().attribute(_left->_data.nodetest);

                                return attr && strequal(attr.value(), value) && is_xpath_attribute(attr.name());
                        }

                        case ast_variable:
                        {
                                assert(_rettype == _data.variable->type());

                                if (_rettype == xpath_type_boolean)
                                        return _data.variable->get_boolean();
                        }

                        // fallthrough
                        default:
                        {
                                switch (_rettype)
                                {
                                case xpath_type_number:
                                        return convert_number_to_boolean(eval_number(c, stack));

                                case xpath_type_string:
                                {
                                        xpath_allocator_capture cr(stack.result);

                                        return !eval_string(c, stack).empty();
                                }

                                case xpath_type_node_set:
                                {
                                        xpath_allocator_capture cr(stack.result);

                                        return !eval_node_set(c, stack, nodeset_eval_any).empty();
                                }

                                default:
                                        assert(false && "Wrong expression for return type boolean"); // unreachable
                                        return false;
                                }
                        }
                        }
                }

                double eval_number(const xpath_context& c, const xpath_stack& stack)
                {
                        switch (_type)
                        {
                        case ast_op_add:
                                return _left->eval_number(c, stack) + _right->eval_number(c, stack);

                        case ast_op_subtract:
                                return _left->eval_number(c, stack) - _right->eval_number(c, stack);

                        case ast_op_multiply:
                                return _left->eval_number(c, stack) * _right->eval_number(c, stack);

                        case ast_op_divide:
                                return _left->eval_number(c, stack) / _right->eval_number(c, stack);

                        case ast_op_mod:
                                return fmod(_left->eval_number(c, stack), _right->eval_number(c, stack));

                        case ast_op_negate:
                                return -_left->eval_number(c, stack);

                        case ast_number_constant:
                                return _data.number;

                        case ast_func_last:
                                return static_cast<double>(c.size);

                        case ast_func_position:
                                return static_cast<double>(c.position);

                        case ast_func_count:
                        {
                                xpath_allocator_capture cr(stack.result);

                                return static_cast<double>(_left->eval_node_set(c, stack, nodeset_eval_all).size());
                        }

                        case ast_func_string_length_0:
                        {
                                xpath_allocator_capture cr(stack.result);

                                return static_cast<double>(string_value(c.n, stack.result).length());
                        }

                        case ast_func_string_length_1:
                        {
                                xpath_allocator_capture cr(stack.result);

                                return static_cast<double>(_left->eval_string(c, stack).length());
                        }

                        case ast_func_number_0:
                        {
                                xpath_allocator_capture cr(stack.result);

                                return convert_string_to_number(string_value(c.n, stack.result).c_str());
                        }

                        case ast_func_number_1:
                                return _left->eval_number(c, stack);

                        case ast_func_sum:
                        {
                                xpath_allocator_capture cr(stack.result);

                                double r = 0;

                                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_all);

                                for (const xpath_node* it = ns.begin(); it != ns.end(); ++it)
                                {
                                        xpath_allocator_capture cri(stack.result);

                                        r += convert_string_to_number(string_value(*it, stack.result).c_str());
                                }

                                return r;
                        }

                        case ast_func_floor:
                        {
                                double r = _left->eval_number(c, stack);

                                return r == r ? floor(r) : r;
                        }

                        case ast_func_ceiling:
                        {
                                double r = _left->eval_number(c, stack);

                                return r == r ? ceil(r) : r;
                        }

                        case ast_func_round:
                                return round_nearest_nzero(_left->eval_number(c, stack));

                        case ast_variable:
                        {
                                assert(_rettype == _data.variable->type());

                                if (_rettype == xpath_type_number)
                                        return _data.variable->get_number();
                        }

                        // fallthrough
                        default:
                        {
                                switch (_rettype)
                                {
                                case xpath_type_boolean:
                                        return eval_boolean(c, stack) ? 1 : 0;

                                case xpath_type_string:
                                {
                                        xpath_allocator_capture cr(stack.result);

                                        return convert_string_to_number(eval_string(c, stack).c_str());
                                }

                                case xpath_type_node_set:
                                {
                                        xpath_allocator_capture cr(stack.result);

                                        return convert_string_to_number(eval_string(c, stack).c_str());
                                }

                                default:
                                        assert(false && "Wrong expression for return type number"); // unreachable
                                        return 0;
                                }

                        }
                        }
                }

                xpath_string eval_string_concat(const xpath_context& c, const xpath_stack& stack)
                {
                        assert(_type == ast_func_concat);

                        xpath_allocator_capture ct(stack.temp);

                        // count the string number
                        size_t count = 1;
                        for (xpath_ast_node* nc = _right; nc; nc = nc->_next) count++;

                        // allocate a buffer for temporary string objects
                        xpath_string* buffer = static_cast<xpath_string*>(stack.temp->allocate(count * sizeof(xpath_string)));
                        if (!buffer) return xpath_string();

                        // evaluate all strings to temporary stack
                        xpath_stack swapped_stack = {stack.temp, stack.result};

                        buffer[0] = _left->eval_string(c, swapped_stack);

                        size_t pos = 1;
                        for (xpath_ast_node* n = _right; n; n = n->_next, ++pos) buffer[pos] = n->eval_string(c, swapped_stack);
                        assert(pos == count);

                        // get total length
                        size_t length = 0;
                        for (size_t i = 0; i < count; ++i) length += buffer[i].length();

                        // create final string
                        char_t* result = static_cast<char_t*>(stack.result->allocate((length + 1) * sizeof(char_t)));
                        if (!result) return xpath_string();

                        char_t* ri = result;

                        for (size_t j = 0; j < count; ++j)
                                for (const char_t* bi = buffer[j].c_str(); *bi; ++bi)
                                        *ri++ = *bi;

                        *ri = 0;

                        return xpath_string::from_heap_preallocated(result, ri);
                }

                xpath_string eval_string(const xpath_context& c, const xpath_stack& stack)
                {
                        switch (_type)
                        {
                        case ast_string_constant:
                                return xpath_string::from_const(_data.string);

                        case ast_func_local_name_0:
                        {
                                xpath_node na = c.n;

                                return xpath_string::from_const(local_name(na));
                        }

                        case ast_func_local_name_1:
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_first);
                                xpath_node na = ns.first();

                                return xpath_string::from_const(local_name(na));
                        }

                        case ast_func_name_0:
                        {
                                xpath_node na = c.n;

                                return xpath_string::from_const(qualified_name(na));
                        }

                        case ast_func_name_1:
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_first);
                                xpath_node na = ns.first();

                                return xpath_string::from_const(qualified_name(na));
                        }

                        case ast_func_namespace_uri_0:
                        {
                                xpath_node na = c.n;

                                return xpath_string::from_const(namespace_uri(na));
                        }

                        case ast_func_namespace_uri_1:
                        {
                                xpath_allocator_capture cr(stack.result);

                                xpath_node_set_raw ns = _left->eval_node_set(c, stack, nodeset_eval_first);
                                xpath_node na = ns.first();

                                return xpath_string::from_const(namespace_uri(na));
                        }

                        case ast_func_string_0:
                                return string_value(c.n, stack.result);

                        case ast_func_string_1:
                                return _left->eval_string(c, stack);

                        case ast_func_concat:
                                return eval_string_concat(c, stack);

                        case ast_func_substring_before:
                        {
                                xpath_allocator_capture cr(stack.temp);

                                xpath_stack swapped_stack = {stack.temp, stack.result};

                                xpath_string s = _left->eval_string(c, swapped_stack);
                                xpath_string p = _right->eval_string(c, swapped_stack);

                                const char_t* pos = find_substring(s.c_str(), p.c_str());

                                return pos ? xpath_string::from_heap(s.c_str(), pos, stack.result) : xpath_string();
                        }

                        case ast_func_substring_after:
                        {
                                xpath_allocator_capture cr(stack.temp);

                                xpath_stack swapped_stack = {stack.temp, stack.result};

                                xpath_string s = _left->eval_string(c, swapped_stack);
                                xpath_string p = _right->eval_string(c, swapped_stack);

                                const char_t* pos = find_substring(s.c_str(), p.c_str());
                                if (!pos) return xpath_string();

                                const char_t* rbegin = pos + p.length();
                                const char_t* rend = s.c_str() + s.length();

                                return s.uses_heap() ? xpath_string::from_heap(rbegin, rend, stack.result) : xpath_string::from_const(rbegin);
                        }

                        case ast_func_substring_2:
                        {
                                xpath_allocator_capture cr(stack.temp);

                                xpath_stack swapped_stack = {stack.temp, stack.result};

                                xpath_string s = _left->eval_string(c, swapped_stack);
                                size_t s_length = s.length();

                                double first = round_nearest(_right->eval_number(c, stack));

                                if (is_nan(first)) return xpath_string(); // NaN
                                else if (first >= s_length + 1) return xpath_string();

                                size_t pos = first < 1 ? 1 : static_cast<size_t>(first);
                                assert(1 <= pos && pos <= s_length + 1);

                                const char_t* rbegin = s.c_str() + (pos - 1);
                                const char_t* rend = s.c_str() + s.length();

                                return s.uses_heap() ? xpath_string::from_heap(rbegin, rend, stack.result) : xpath_string::from_const(rbegin);
                        }

                        case ast_func_substring_3:
                        {
                                xpath_allocator_capture cr(stack.temp);

                                xpath_stack swapped_stack = {stack.temp, stack.result};

                                xpath_string s = _left->eval_string(c, swapped_stack);
                                size_t s_length = s.length();

                                double first = round_nearest(_right->eval_number(c, stack));
                                double last = first + round_nearest(_right->_next->eval_number(c, stack));

                                if (is_nan(first) || is_nan(last)) return xpath_string();
                                else if (first >= s_length + 1) return xpath_string();
                                else if (first >= last) return xpath_string();
                                else if (last < 1) return xpath_string();

                                size_t pos = first < 1 ? 1 : static_cast<size_t>(first);
                                size_t end = last >= s_length + 1 ? s_length + 1 : static_cast<size_t>(last);

                                assert(1 <= pos && pos <= end && end <= s_length + 1);
                                const char_t* rbegin = s.c_str() + (pos - 1);
                                const char_t* rend = s.c_str() + (end - 1);

                                return (end == s_length + 1 && !s.uses_heap()) ? xpath_string::from_const(rbegin) : xpath_string::from_heap(rbegin, rend, stack.result);
                        }

                        case ast_func_normalize_space_0:
                        {
                                xpath_string s = string_value(c.n, stack.result);

                                char_t* begin = s.data(stack.result);
                                if (!begin) return xpath_string();

                                char_t* end = normalize_space(begin);

                                return xpath_string::from_heap_preallocated(begin, end);
                        }

                        case ast_func_normalize_space_1:
                        {
                                xpath_string s = _left->eval_string(c, stack);

                                char_t* begin = s.data(stack.result);
                                if (!begin) return xpath_string();

                                char_t* end = normalize_space(begin);

                                return xpath_string::from_heap_preallocated(begin, end);
                        }

                        case ast_func_translate:
                        {
                                xpath_allocator_capture cr(stack.temp);

                                xpath_stack swapped_stack = {stack.temp, stack.result};

                                xpath_string s = _left->eval_string(c, stack);
                                xpath_string from = _right->eval_string(c, swapped_stack);
                                xpath_string to = _right->_next->eval_string(c, swapped_stack);

                                char_t* begin = s.data(stack.result);
                                if (!begin) return xpath_string();

                                char_t* end = translate(begin, from.c_str(), to.c_str(), to.length());

                                return xpath_string::from_heap_preallocated(begin, end);
                        }

                        case ast_opt_translate_table:
                        {
                                xpath_string s = _left->eval_string(c, stack);

                                char_t* begin = s.data(stack.result);
                                if (!begin) return xpath_string();

                                char_t* end = translate_table(begin, _data.table);

                                return xpath_string::from_heap_preallocated(begin, end);
                        }

                        case ast_variable:
                        {
                                assert(_rettype == _data.variable->type());

                                if (_rettype == xpath_type_string)
                                        return xpath_string::from_const(_data.variable->get_string());
                        }

                        // fallthrough
                        default:
                        {
                                switch (_rettype)
                                {
                                case xpath_type_boolean:
                                        return xpath_string::from_const(eval_boolean(c, stack) ? PUGIXML_TEXT("true") : PUGIXML_TEXT("false"));

                                case xpath_type_number:
                                        return convert_number_to_string(eval_number(c, stack), stack.result);

                                case xpath_type_node_set:
                                {
                                        xpath_allocator_capture cr(stack.temp);

                                        xpath_stack swapped_stack = {stack.temp, stack.result};

                                        xpath_node_set_raw ns = eval_node_set(c, swapped_stack, nodeset_eval_first);
                                        return ns.empty() ? xpath_string() : string_value(ns.first(), stack.result);
                                }

                                default:
                                        assert(false && "Wrong expression for return type string"); // unreachable
                                        return xpath_string();
                                }
                        }
                        }
                }

                xpath_node_set_raw eval_node_set(const xpath_context& c, const xpath_stack& stack, nodeset_eval_t eval)
                {
                        switch (_type)
                        {
                        case ast_op_union:
                        {
                                xpath_allocator_capture cr(stack.temp);

                                xpath_stack swapped_stack = {stack.temp, stack.result};

                                xpath_node_set_raw ls = _left->eval_node_set(c, swapped_stack, eval);
                                xpath_node_set_raw rs = _right->eval_node_set(c, stack, eval);

                                // we can optimize merging two sorted sets, but this is a very rare operation, so don't bother
                                rs.set_type(xpath_node_set::type_unsorted);

                                rs.append(ls.begin(), ls.end(), stack.result);
                                rs.remove_duplicates();

                                return rs;
                        }

                        case ast_filter:
                        {
                                xpath_node_set_raw set = _left->eval_node_set(c, stack, _test == predicate_constant_one ? nodeset_eval_first : nodeset_eval_all);

                                // either expression is a number or it contains position() call; sort by document order
                                if (_test != predicate_posinv) set.sort_do();

                                bool once = eval_once(set.type(), eval);

                                apply_predicate(set, 0, stack, once);

                                return set;
                        }

                        case ast_func_id:
                                return xpath_node_set_raw();

                        case ast_step:
                        {
                                switch (_axis)
                                {
                                case axis_ancestor:
                                        return step_do(c, stack, eval, axis_to_type<axis_ancestor>());

                                case axis_ancestor_or_self:
                                        return step_do(c, stack, eval, axis_to_type<axis_ancestor_or_self>());

                                case axis_attribute:
                                        return step_do(c, stack, eval, axis_to_type<axis_attribute>());

                                case axis_child:
                                        return step_do(c, stack, eval, axis_to_type<axis_child>());

                                case axis_descendant:
                                        return step_do(c, stack, eval, axis_to_type<axis_descendant>());

                                case axis_descendant_or_self:
                                        return step_do(c, stack, eval, axis_to_type<axis_descendant_or_self>());

                                case axis_following:
                                        return step_do(c, stack, eval, axis_to_type<axis_following>());

                                case axis_following_sibling:
                                        return step_do(c, stack, eval, axis_to_type<axis_following_sibling>());

                                case axis_namespace:
                                        // namespaced axis is not supported
                                        return xpath_node_set_raw();

                                case axis_parent:
                                        return step_do(c, stack, eval, axis_to_type<axis_parent>());

                                case axis_preceding:
                                        return step_do(c, stack, eval, axis_to_type<axis_preceding>());

                                case axis_preceding_sibling:
                                        return step_do(c, stack, eval, axis_to_type<axis_preceding_sibling>());

                                case axis_self:
                                        return step_do(c, stack, eval, axis_to_type<axis_self>());

                                default:
                                        assert(false && "Unknown axis"); // unreachable
                                        return xpath_node_set_raw();
                                }
                        }

                        case ast_step_root:
                        {
                                assert(!_right); // root step can't have any predicates

                                xpath_node_set_raw ns;

                                ns.set_type(xpath_node_set::type_sorted);

                                if (c.n.node()) ns.push_back(c.n.node().root(), stack.result);
                                else if (c.n.attribute()) ns.push_back(c.n.parent().root(), stack.result);

                                return ns;
                        }

                        case ast_variable:
                        {
                                assert(_rettype == _data.variable->type());

                                if (_rettype == xpath_type_node_set)
                                {
                                        const xpath_node_set& s = _data.variable->get_node_set();

                                        xpath_node_set_raw ns;

                                        ns.set_type(s.type());
                                        ns.append(s.begin(), s.end(), stack.result);

                                        return ns;
                                }
                        }

                        // fallthrough
                        default:
                                assert(false && "Wrong expression for return type node set"); // unreachable
                                return xpath_node_set_raw();
                        }
                }

                void optimize(xpath_allocator* alloc)
                {
                        if (_left)
                                _left->optimize(alloc);

                        if (_right)
                                _right->optimize(alloc);

                        if (_next)
                                _next->optimize(alloc);

                        optimize_self(alloc);
                }

                void optimize_self(xpath_allocator* alloc)
                {
                        // Rewrite [position()=expr] with [expr]
                        // Note that this step has to go before classification to recognize [position()=1]
                        if ((_type == ast_filter || _type == ast_predicate) &&
                                _right->_type == ast_op_equal && _right->_left->_type == ast_func_position && _right->_right->_rettype == xpath_type_number)
                        {
                                _right = _right->_right;
                        }

                        // Classify filter/predicate ops to perform various optimizations during evaluation
                        if (_type == ast_filter || _type == ast_predicate)
                        {
                                assert(_test == predicate_default);

                                if (_right->_type == ast_number_constant && _right->_data.number == 1.0)
                                        _test = predicate_constant_one;
                                else if (_right->_rettype == xpath_type_number && (_right->_type == ast_number_constant || _right->_type == ast_variable || _right->_type == ast_func_last))
                                        _test = predicate_constant;
                                else if (_right->_rettype != xpath_type_number && _right->is_posinv_expr())
                                        _test = predicate_posinv;
                        }

                        // Rewrite descendant-or-self::node()/child::foo with descendant::foo
                        // The former is a full form of //foo, the latter is much faster since it executes the node test immediately
                        // Do a similar kind of rewrite for self/descendant/descendant-or-self axes
                        // Note that we only rewrite positionally invariant steps (//foo[1] != /descendant::foo[1])
                        if (_type == ast_step && (_axis == axis_child || _axis == axis_self || _axis == axis_descendant || _axis == axis_descendant_or_self) && _left &&
                                _left->_type == ast_step && _left->_axis == axis_descendant_or_self && _left->_test == nodetest_type_node && !_left->_right &&
                                is_posinv_step())
                        {
                                if (_axis == axis_child || _axis == axis_descendant)
                                        _axis = axis_descendant;
                                else
                                        _axis = axis_descendant_or_self;

                                _left = _left->_left;
                        }

                        // Use optimized lookup table implementation for translate() with constant arguments
                        if (_type == ast_func_translate && _right->_type == ast_string_constant && _right->_next->_type == ast_string_constant)
                        {
                                unsigned char* table = translate_table_generate(alloc, _right->_data.string, _right->_next->_data.string);

                                if (table)
                                {
                                        _type = ast_opt_translate_table;
                                        _data.table = table;
                                }
                        }

                        // Use optimized path for @attr = 'value' or @attr = $value
                        if (_type == ast_op_equal &&
                                _left->_type == ast_step && _left->_axis == axis_attribute && _left->_test == nodetest_name && !_left->_left && !_left->_right &&
                                (_right->_type == ast_string_constant || (_right->_type == ast_variable && _right->_rettype == xpath_type_string)))
                        {
                                _type = ast_opt_compare_attribute;
                        }
                }

                bool is_posinv_expr() const
                {
                        switch (_type)
                        {
                        case ast_func_position:
                        case ast_func_last:
                                return false;

                        case ast_string_constant:
                        case ast_number_constant:
                        case ast_variable:
                                return true;

                        case ast_step:
                        case ast_step_root:
                                return true;

                        case ast_predicate:
                        case ast_filter:
                                return true;

                        default:
                                if (_left && !_left->is_posinv_expr()) return false;

                                for (xpath_ast_node* n = _right; n; n = n->_next)
                                        if (!n->is_posinv_expr()) return false;

                                return true;
                        }
                }

                bool is_posinv_step() const
                {
                        assert(_type == ast_step);

                        for (xpath_ast_node* n = _right; n; n = n->_next)
                        {
                                assert(n->_type == ast_predicate);

                                if (n->_test != predicate_posinv)
                                        return false;
                        }

                        return true;
                }

                xpath_value_type rettype() const
                {
                        return static_cast<xpath_value_type>(_rettype);
                }
        };

        struct xpath_parser
        {
                xpath_allocator* _alloc;
                xpath_lexer _lexer;

                const char_t* _query;
                xpath_variable_set* _variables;

                xpath_parse_result* _result;

                char_t _scratch[32];

                xpath_ast_node* error(const char* message)
                {
                        _result->error = message;
                        _result->offset = _lexer.current_pos() - _query;

                        return 0;
                }

                xpath_ast_node* error_oom()
                {
                        assert(_alloc->_error);
                        *_alloc->_error = true;

                        return 0;
                }

                void* alloc_node()
                {
                        return _alloc->allocate(sizeof(xpath_ast_node));
                }

                xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, const char_t* value)
                {
                        void* memory = alloc_node();
                        return memory ? new (memory) xpath_ast_node(type, rettype, value) : 0;
                }

                xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, double value)
                {
                        void* memory = alloc_node();
                        return memory ? new (memory) xpath_ast_node(type, rettype, value) : 0;
                }

                xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, xpath_variable* value)
                {
                        void* memory = alloc_node();
                        return memory ? new (memory) xpath_ast_node(type, rettype, value) : 0;
                }

                xpath_ast_node* alloc_node(ast_type_t type, xpath_value_type rettype, xpath_ast_node* left = 0, xpath_ast_node* right = 0)
                {
                        void* memory = alloc_node();
                        return memory ? new (memory) xpath_ast_node(type, rettype, left, right) : 0;
                }

                xpath_ast_node* alloc_node(ast_type_t type, xpath_ast_node* left, axis_t axis, nodetest_t test, const char_t* contents)
                {
                        void* memory = alloc_node();
                        return memory ? new (memory) xpath_ast_node(type, left, axis, test, contents) : 0;
                }

                xpath_ast_node* alloc_node(ast_type_t type, xpath_ast_node* left, xpath_ast_node* right, predicate_t test)
                {
                        void* memory = alloc_node();
                        return memory ? new (memory) xpath_ast_node(type, left, right, test) : 0;
                }

                const char_t* alloc_string(const xpath_lexer_string& value)
                {
                        if (!value.begin)
                                return PUGIXML_TEXT("");

                        size_t length = static_cast<size_t>(value.end - value.begin);

                        char_t* c = static_cast<char_t*>(_alloc->allocate((length + 1) * sizeof(char_t)));
                        if (!c) return 0;

                        memcpy(c, value.begin, length * sizeof(char_t));
                        c[length] = 0;

                        return c;
                }

                xpath_ast_node* parse_function(const xpath_lexer_string& name, size_t argc, xpath_ast_node* args[2])
                {
                        switch (name.begin[0])
                        {
                        case 'b':
                                if (name == PUGIXML_TEXT("boolean") && argc == 1)
                                        return alloc_node(ast_func_boolean, xpath_type_boolean, args[0]);

                                break;

                        case 'c':
                                if (name == PUGIXML_TEXT("count") && argc == 1)
                                {
                                        if (args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                                        return alloc_node(ast_func_count, xpath_type_number, args[0]);
                                }
                                else if (name == PUGIXML_TEXT("contains") && argc == 2)
                                        return alloc_node(ast_func_contains, xpath_type_boolean, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("concat") && argc >= 2)
                                        return alloc_node(ast_func_concat, xpath_type_string, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("ceiling") && argc == 1)
                                        return alloc_node(ast_func_ceiling, xpath_type_number, args[0]);

                                break;

                        case 'f':
                                if (name == PUGIXML_TEXT("false") && argc == 0)
                                        return alloc_node(ast_func_false, xpath_type_boolean);
                                else if (name == PUGIXML_TEXT("floor") && argc == 1)
                                        return alloc_node(ast_func_floor, xpath_type_number, args[0]);

                                break;

                        case 'i':
                                if (name == PUGIXML_TEXT("id") && argc == 1)
                                        return alloc_node(ast_func_id, xpath_type_node_set, args[0]);

                                break;

                        case 'l':
                                if (name == PUGIXML_TEXT("last") && argc == 0)
                                        return alloc_node(ast_func_last, xpath_type_number);
                                else if (name == PUGIXML_TEXT("lang") && argc == 1)
                                        return alloc_node(ast_func_lang, xpath_type_boolean, args[0]);
                                else if (name == PUGIXML_TEXT("local-name") && argc <= 1)
                                {
                                        if (argc == 1 && args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                                        return alloc_node(argc == 0 ? ast_func_local_name_0 : ast_func_local_name_1, xpath_type_string, args[0]);
                                }

                                break;

                        case 'n':
                                if (name == PUGIXML_TEXT("name") && argc <= 1)
                                {
                                        if (argc == 1 && args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                                        return alloc_node(argc == 0 ? ast_func_name_0 : ast_func_name_1, xpath_type_string, args[0]);
                                }
                                else if (name == PUGIXML_TEXT("namespace-uri") && argc <= 1)
                                {
                                        if (argc == 1 && args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                                        return alloc_node(argc == 0 ? ast_func_namespace_uri_0 : ast_func_namespace_uri_1, xpath_type_string, args[0]);
                                }
                                else if (name == PUGIXML_TEXT("normalize-space") && argc <= 1)
                                        return alloc_node(argc == 0 ? ast_func_normalize_space_0 : ast_func_normalize_space_1, xpath_type_string, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("not") && argc == 1)
                                        return alloc_node(ast_func_not, xpath_type_boolean, args[0]);
                                else if (name == PUGIXML_TEXT("number") && argc <= 1)
                                        return alloc_node(argc == 0 ? ast_func_number_0 : ast_func_number_1, xpath_type_number, args[0]);

                                break;

                        case 'p':
                                if (name == PUGIXML_TEXT("position") && argc == 0)
                                        return alloc_node(ast_func_position, xpath_type_number);

                                break;

                        case 'r':
                                if (name == PUGIXML_TEXT("round") && argc == 1)
                                        return alloc_node(ast_func_round, xpath_type_number, args[0]);

                                break;

                        case 's':
                                if (name == PUGIXML_TEXT("string") && argc <= 1)
                                        return alloc_node(argc == 0 ? ast_func_string_0 : ast_func_string_1, xpath_type_string, args[0]);
                                else if (name == PUGIXML_TEXT("string-length") && argc <= 1)
                                        return alloc_node(argc == 0 ? ast_func_string_length_0 : ast_func_string_length_1, xpath_type_number, args[0]);
                                else if (name == PUGIXML_TEXT("starts-with") && argc == 2)
                                        return alloc_node(ast_func_starts_with, xpath_type_boolean, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("substring-before") && argc == 2)
                                        return alloc_node(ast_func_substring_before, xpath_type_string, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("substring-after") && argc == 2)
                                        return alloc_node(ast_func_substring_after, xpath_type_string, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("substring") && (argc == 2 || argc == 3))
                                        return alloc_node(argc == 2 ? ast_func_substring_2 : ast_func_substring_3, xpath_type_string, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("sum") && argc == 1)
                                {
                                        if (args[0]->rettype() != xpath_type_node_set) return error("Function has to be applied to node set");
                                        return alloc_node(ast_func_sum, xpath_type_number, args[0]);
                                }

                                break;

                        case 't':
                                if (name == PUGIXML_TEXT("translate") && argc == 3)
                                        return alloc_node(ast_func_translate, xpath_type_string, args[0], args[1]);
                                else if (name == PUGIXML_TEXT("true") && argc == 0)
                                        return alloc_node(ast_func_true, xpath_type_boolean);

                                break;

                        default:
                                break;
                        }

                        return error("Unrecognized function or wrong parameter count");
                }

                axis_t parse_axis_name(const xpath_lexer_string& name, bool& specified)
                {
                        specified = true;

                        switch (name.begin[0])
                        {
                        case 'a':
                                if (name == PUGIXML_TEXT("ancestor"))
                                        return axis_ancestor;
                                else if (name == PUGIXML_TEXT("ancestor-or-self"))
                                        return axis_ancestor_or_self;
                                else if (name == PUGIXML_TEXT("attribute"))
                                        return axis_attribute;

                                break;

                        case 'c':
                                if (name == PUGIXML_TEXT("child"))
                                        return axis_child;

                                break;

                        case 'd':
                                if (name == PUGIXML_TEXT("descendant"))
                                        return axis_descendant;
                                else if (name == PUGIXML_TEXT("descendant-or-self"))
                                        return axis_descendant_or_self;

                                break;

                        case 'f':
                                if (name == PUGIXML_TEXT("following"))
                                        return axis_following;
                                else if (name == PUGIXML_TEXT("following-sibling"))
                                        return axis_following_sibling;

                                break;

                        case 'n':
                                if (name == PUGIXML_TEXT("namespace"))
                                        return axis_namespace;

                                break;

                        case 'p':
                                if (name == PUGIXML_TEXT("parent"))
                                        return axis_parent;
                                else if (name == PUGIXML_TEXT("preceding"))
                                        return axis_preceding;
                                else if (name == PUGIXML_TEXT("preceding-sibling"))
                                        return axis_preceding_sibling;

                                break;

                        case 's':
                                if (name == PUGIXML_TEXT("self"))
                                        return axis_self;

                                break;

                        default:
                                break;
                        }

                        specified = false;
                        return axis_child;
                }

                nodetest_t parse_node_test_type(const xpath_lexer_string& name)
                {
                        switch (name.begin[0])
                        {
                        case 'c':
                                if (name == PUGIXML_TEXT("comment"))
                                        return nodetest_type_comment;

                                break;

                        case 'n':
                                if (name == PUGIXML_TEXT("node"))
                                        return nodetest_type_node;

                                break;

                        case 'p':
                                if (name == PUGIXML_TEXT("processing-instruction"))
                                        return nodetest_type_pi;

                                break;

                        case 't':
                                if (name == PUGIXML_TEXT("text"))
                                        return nodetest_type_text;

                                break;

                        default:
                                break;
                        }

                        return nodetest_none;
                }

                // PrimaryExpr ::= VariableReference | '(' Expr ')' | Literal | Number | FunctionCall
                xpath_ast_node* parse_primary_expression()
                {
                        switch (_lexer.current())
                        {
                        case lex_var_ref:
                        {
                                xpath_lexer_string name = _lexer.contents();

                                if (!_variables)
                                        return error("Unknown variable: variable set is not provided");

                                xpath_variable* var = 0;
                                if (!get_variable_scratch(_scratch, _variables, name.begin, name.end, &var))
                                        return error_oom();

                                if (!var)
                                        return error("Unknown variable: variable set does not contain the given name");

                                _lexer.next();

                                return alloc_node(ast_variable, var->type(), var);
                        }

                        case lex_open_brace:
                        {
                                _lexer.next();

                                xpath_ast_node* n = parse_expression();
                                if (!n) return 0;

                                if (_lexer.current() != lex_close_brace)
                                        return error("Expected ')' to match an opening '('");

                                _lexer.next();

                                return n;
                        }

                        case lex_quoted_string:
                        {
                                const char_t* value = alloc_string(_lexer.contents());
                                if (!value) return 0;

                                _lexer.next();

                                return alloc_node(ast_string_constant, xpath_type_string, value);
                        }

                        case lex_number:
                        {
                                double value = 0;

                                if (!convert_string_to_number_scratch(_scratch, _lexer.contents().begin, _lexer.contents().end, &value))
                                        return error_oom();

                                _lexer.next();

                                return alloc_node(ast_number_constant, xpath_type_number, value);
                        }

                        case lex_string:
                        {
                                xpath_ast_node* args[2] = {0};
                                size_t argc = 0;

                                xpath_lexer_string function = _lexer.contents();
                                _lexer.next();

                                xpath_ast_node* last_arg = 0;

                                if (_lexer.current() != lex_open_brace)
                                        return error("Unrecognized function call");
                                _lexer.next();

                                while (_lexer.current() != lex_close_brace)
                                {
                                        if (argc > 0)
                                        {
                                                if (_lexer.current() != lex_comma)
                                                        return error("No comma between function arguments");
                                                _lexer.next();
                                        }

                                        xpath_ast_node* n = parse_expression();
                                        if (!n) return 0;

                                        if (argc < 2) args[argc] = n;
                                        else last_arg->set_next(n);

                                        argc++;
                                        last_arg = n;
                                }

                                _lexer.next();

                                return parse_function(function, argc, args);
                        }

                        default:
                                return error("Unrecognizable primary expression");
                        }
                }

                // FilterExpr ::= PrimaryExpr | FilterExpr Predicate
                // Predicate ::= '[' PredicateExpr ']'
                // PredicateExpr ::= Expr
                xpath_ast_node* parse_filter_expression()
                {
                        xpath_ast_node* n = parse_primary_expression();
                        if (!n) return 0;

                        while (_lexer.current() == lex_open_square_brace)
                        {
                                _lexer.next();

                                if (n->rettype() != xpath_type_node_set)
                                        return error("Predicate has to be applied to node set");

                                xpath_ast_node* expr = parse_expression();
                                if (!expr) return 0;

                                n = alloc_node(ast_filter, n, expr, predicate_default);
                                if (!n) return 0;

                                if (_lexer.current() != lex_close_square_brace)
                                        return error("Expected ']' to match an opening '['");

                                _lexer.next();
                        }

                        return n;
                }

                // Step ::= AxisSpecifier NodeTest Predicate* | AbbreviatedStep
                // AxisSpecifier ::= AxisName '::' | '@'?
                // NodeTest ::= NameTest | NodeType '(' ')' | 'processing-instruction' '(' Literal ')'
                // NameTest ::= '*' | NCName ':' '*' | QName
                // AbbreviatedStep ::= '.' | '..'
                xpath_ast_node* parse_step(xpath_ast_node* set)
                {
                        if (set && set->rettype() != xpath_type_node_set)
                                return error("Step has to be applied to node set");

                        bool axis_specified = false;
                        axis_t axis = axis_child; // implied child axis

                        if (_lexer.current() == lex_axis_attribute)
                        {
                                axis = axis_attribute;
                                axis_specified = true;

                                _lexer.next();
                        }
                        else if (_lexer.current() == lex_dot)
                        {
                                _lexer.next();

                                if (_lexer.current() == lex_open_square_brace)
                                        return error("Predicates are not allowed after an abbreviated step");

                                return alloc_node(ast_step, set, axis_self, nodetest_type_node, 0);
                        }
                        else if (_lexer.current() == lex_double_dot)
                        {
                                _lexer.next();

                                if (_lexer.current() == lex_open_square_brace)
                                        return error("Predicates are not allowed after an abbreviated step");

                                return alloc_node(ast_step, set, axis_parent, nodetest_type_node, 0);
                        }

                        nodetest_t nt_type = nodetest_none;
                        xpath_lexer_string nt_name;

                        if (_lexer.current() == lex_string)
                        {
                                // node name test
                                nt_name = _lexer.contents();
                                _lexer.next();

                                // was it an axis name?
                                if (_lexer.current() == lex_double_colon)
                                {
                                        // parse axis name
                                        if (axis_specified)
                                                return error("Two axis specifiers in one step");

                                        axis = parse_axis_name(nt_name, axis_specified);

                                        if (!axis_specified)
                                                return error("Unknown axis");

                                        // read actual node test
                                        _lexer.next();

                                        if (_lexer.current() == lex_multiply)
                                        {
                                                nt_type = nodetest_all;
                                                nt_name = xpath_lexer_string();
                                                _lexer.next();
                                        }
                                        else if (_lexer.current() == lex_string)
                                        {
                                                nt_name = _lexer.contents();
                                                _lexer.next();
                                        }
                                        else
                                        {
                                                return error("Unrecognized node test");
                                        }
                                }

                                if (nt_type == nodetest_none)
                                {
                                        // node type test or processing-instruction
                                        if (_lexer.current() == lex_open_brace)
                                        {
                                                _lexer.next();

                                                if (_lexer.current() == lex_close_brace)
                                                {
                                                        _lexer.next();

                                                        nt_type = parse_node_test_type(nt_name);

                                                        if (nt_type == nodetest_none)
                                                                return error("Unrecognized node type");

                                                        nt_name = xpath_lexer_string();
                                                }
                                                else if (nt_name == PUGIXML_TEXT("processing-instruction"))
                                                {
                                                        if (_lexer.current() != lex_quoted_string)
                                                                return error("Only literals are allowed as arguments to processing-instruction()");

                                                        nt_type = nodetest_pi;
                                                        nt_name = _lexer.contents();
                                                        _lexer.next();

                                                        if (_lexer.current() != lex_close_brace)
                                                                return error("Unmatched brace near processing-instruction()");
                                                        _lexer.next();
                                                }
                                                else
                                                {
                                                        return error("Unmatched brace near node type test");
                                                }
                                        }
                                        // QName or NCName:*
                                        else
                                        {
                                                if (nt_name.end - nt_name.begin > 2 && nt_name.end[-2] == ':' && nt_name.end[-1] == '*') // NCName:*
                                                {
                                                        nt_name.end--; // erase *

                                                        nt_type = nodetest_all_in_namespace;
                                                }
                                                else
                                                {
                                                        nt_type = nodetest_name;
                                                }
                                        }
                                }
                        }
                        else if (_lexer.current() == lex_multiply)
                        {
                                nt_type = nodetest_all;
                                _lexer.next();
                        }
                        else
                        {
                                return error("Unrecognized node test");
                        }

                        const char_t* nt_name_copy = alloc_string(nt_name);
                        if (!nt_name_copy) return 0;

                        xpath_ast_node* n = alloc_node(ast_step, set, axis, nt_type, nt_name_copy);
                        if (!n) return 0;

                        xpath_ast_node* last = 0;

                        while (_lexer.current() == lex_open_square_brace)
                        {
                                _lexer.next();

                                xpath_ast_node* expr = parse_expression();
                                if (!expr) return 0;

                                xpath_ast_node* pred = alloc_node(ast_predicate, 0, expr, predicate_default);
                                if (!pred) return 0;

                                if (_lexer.current() != lex_close_square_brace)
                                        return error("Expected ']' to match an opening '['");
                                _lexer.next();

                                if (last) last->set_next(pred);
                                else n->set_right(pred);

                                last = pred;
                        }

                        return n;
                }

                // RelativeLocationPath ::= Step | RelativeLocationPath '/' Step | RelativeLocationPath '//' Step
                xpath_ast_node* parse_relative_location_path(xpath_ast_node* set)
                {
                        xpath_ast_node* n = parse_step(set);
                        if (!n) return 0;

                        while (_lexer.current() == lex_slash || _lexer.current() == lex_double_slash)
                        {
                                lexeme_t l = _lexer.current();
                                _lexer.next();

                                if (l == lex_double_slash)
                                {
                                        n = alloc_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, 0);
                                        if (!n) return 0;
                                }

                                n = parse_step(n);
                                if (!n) return 0;
                        }

                        return n;
                }

                // LocationPath ::= RelativeLocationPath | AbsoluteLocationPath
                // AbsoluteLocationPath ::= '/' RelativeLocationPath? | '//' RelativeLocationPath
                xpath_ast_node* parse_location_path()
                {
                        if (_lexer.current() == lex_slash)
                        {
                                _lexer.next();

                                xpath_ast_node* n = alloc_node(ast_step_root, xpath_type_node_set);
                                if (!n) return 0;

                                // relative location path can start from axis_attribute, dot, double_dot, multiply and string lexemes; any other lexeme means standalone root path
                                lexeme_t l = _lexer.current();

                                if (l == lex_string || l == lex_axis_attribute || l == lex_dot || l == lex_double_dot || l == lex_multiply)
                                        return parse_relative_location_path(n);
                                else
                                        return n;
                        }
                        else if (_lexer.current() == lex_double_slash)
                        {
                                _lexer.next();

                                xpath_ast_node* n = alloc_node(ast_step_root, xpath_type_node_set);
                                if (!n) return 0;

                                n = alloc_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, 0);
                                if (!n) return 0;

                                return parse_relative_location_path(n);
                        }

                        // else clause moved outside of if because of bogus warning 'control may reach end of non-void function being inlined' in gcc 4.0.1
                        return parse_relative_location_path(0);
                }

                // PathExpr ::= LocationPath
                //                              | FilterExpr
                //                              | FilterExpr '/' RelativeLocationPath
                //                              | FilterExpr '//' RelativeLocationPath
                // UnionExpr ::= PathExpr | UnionExpr '|' PathExpr
                // UnaryExpr ::= UnionExpr | '-' UnaryExpr
                xpath_ast_node* parse_path_or_unary_expression()
                {
                        // Clarification.
                        // PathExpr begins with either LocationPath or FilterExpr.
                        // FilterExpr begins with PrimaryExpr
                        // PrimaryExpr begins with '$' in case of it being a variable reference,
                        // '(' in case of it being an expression, string literal, number constant or
                        // function call.
                        if (_lexer.current() == lex_var_ref || _lexer.current() == lex_open_brace ||
                                _lexer.current() == lex_quoted_string || _lexer.current() == lex_number ||
                                _lexer.current() == lex_string)
                        {
                                if (_lexer.current() == lex_string)
                                {
                                        // This is either a function call, or not - if not, we shall proceed with location path
                                        const char_t* state = _lexer.state();

                                        while (PUGI__IS_CHARTYPE(*state, ct_space)) ++state;

                                        if (*state != '(')
                                                return parse_location_path();

                                        // This looks like a function call; however this still can be a node-test. Check it.
                                        if (parse_node_test_type(_lexer.contents()) != nodetest_none)
                                                return parse_location_path();
                                }

                                xpath_ast_node* n = parse_filter_expression();
                                if (!n) return 0;

                                if (_lexer.current() == lex_slash || _lexer.current() == lex_double_slash)
                                {
                                        lexeme_t l = _lexer.current();
                                        _lexer.next();

                                        if (l == lex_double_slash)
                                        {
                                                if (n->rettype() != xpath_type_node_set)
                                                        return error("Step has to be applied to node set");

                                                n = alloc_node(ast_step, n, axis_descendant_or_self, nodetest_type_node, 0);
                                                if (!n) return 0;
                                        }

                                        // select from location path
                                        return parse_relative_location_path(n);
                                }

                                return n;
                        }
                        else if (_lexer.current() == lex_minus)
                        {
                                _lexer.next();

                                // precedence 7+ - only parses union expressions
                                xpath_ast_node* n = parse_expression(7);
                                if (!n) return 0;

                                return alloc_node(ast_op_negate, xpath_type_number, n);
                        }
                        else
                        {
                                return parse_location_path();
                        }
                }

                struct binary_op_t
                {
                        ast_type_t asttype;
                        xpath_value_type rettype;
                        int precedence;

                        binary_op_t(): asttype(ast_unknown), rettype(xpath_type_none), precedence(0)
                        {
                        }

                        binary_op_t(ast_type_t asttype_, xpath_value_type rettype_, int precedence_): asttype(asttype_), rettype(rettype_), precedence(precedence_)
                        {
                        }

                        static binary_op_t parse(xpath_lexer& lexer)
                        {
                                switch (lexer.current())
                                {
                                case lex_string:
                                        if (lexer.contents() == PUGIXML_TEXT("or"))
                                                return binary_op_t(ast_op_or, xpath_type_boolean, 1);
                                        else if (lexer.contents() == PUGIXML_TEXT("and"))
                                                return binary_op_t(ast_op_and, xpath_type_boolean, 2);
                                        else if (lexer.contents() == PUGIXML_TEXT("div"))
                                                return binary_op_t(ast_op_divide, xpath_type_number, 6);
                                        else if (lexer.contents() == PUGIXML_TEXT("mod"))
                                                return binary_op_t(ast_op_mod, xpath_type_number, 6);
                                        else
                                                return binary_op_t();

                                case lex_equal:
                                        return binary_op_t(ast_op_equal, xpath_type_boolean, 3);

                                case lex_not_equal:
                                        return binary_op_t(ast_op_not_equal, xpath_type_boolean, 3);

                                case lex_less:
                                        return binary_op_t(ast_op_less, xpath_type_boolean, 4);

                                case lex_greater:
                                        return binary_op_t(ast_op_greater, xpath_type_boolean, 4);

                                case lex_less_or_equal:
                                        return binary_op_t(ast_op_less_or_equal, xpath_type_boolean, 4);

                                case lex_greater_or_equal:
                                        return binary_op_t(ast_op_greater_or_equal, xpath_type_boolean, 4);

                                case lex_plus:
                                        return binary_op_t(ast_op_add, xpath_type_number, 5);

                                case lex_minus:
                                        return binary_op_t(ast_op_subtract, xpath_type_number, 5);

                                case lex_multiply:
                                        return binary_op_t(ast_op_multiply, xpath_type_number, 6);

                                case lex_union:
                                        return binary_op_t(ast_op_union, xpath_type_node_set, 7);

                                default:
                                        return binary_op_t();
                                }
                        }
                };

                xpath_ast_node* parse_expression_rec(xpath_ast_node* lhs, int limit)
                {
                        binary_op_t op = binary_op_t::parse(_lexer);

                        while (op.asttype != ast_unknown && op.precedence >= limit)
                        {
                                _lexer.next();

                                xpath_ast_node* rhs = parse_path_or_unary_expression();
                                if (!rhs) return 0;

                                binary_op_t nextop = binary_op_t::parse(_lexer);

                                while (nextop.asttype != ast_unknown && nextop.precedence > op.precedence)
                                {
                                        rhs = parse_expression_rec(rhs, nextop.precedence);
                                        if (!rhs) return 0;

                                        nextop = binary_op_t::parse(_lexer);
                                }

                                if (op.asttype == ast_op_union && (lhs->rettype() != xpath_type_node_set || rhs->rettype() != xpath_type_node_set))
                                        return error("Union operator has to be applied to node sets");

                                lhs = alloc_node(op.asttype, op.rettype, lhs, rhs);
                                if (!lhs) return 0;

                                op = binary_op_t::parse(_lexer);
                        }

                        return lhs;
                }

                // Expr ::= OrExpr
                // OrExpr ::= AndExpr | OrExpr 'or' AndExpr
                // AndExpr ::= EqualityExpr | AndExpr 'and' EqualityExpr
                // EqualityExpr ::= RelationalExpr
                //                                      | EqualityExpr '=' RelationalExpr
                //                                      | EqualityExpr '!=' RelationalExpr
                // RelationalExpr ::= AdditiveExpr
                //                                        | RelationalExpr '<' AdditiveExpr
                //                                        | RelationalExpr '>' AdditiveExpr
                //                                        | RelationalExpr '<=' AdditiveExpr
                //                                        | RelationalExpr '>=' AdditiveExpr
                // AdditiveExpr ::= MultiplicativeExpr
                //                                      | AdditiveExpr '+' MultiplicativeExpr
                //                                      | AdditiveExpr '-' MultiplicativeExpr
                // MultiplicativeExpr ::= UnaryExpr
                //                                                | MultiplicativeExpr '*' UnaryExpr
                //                                                | MultiplicativeExpr 'div' UnaryExpr
                //                                                | MultiplicativeExpr 'mod' UnaryExpr
                xpath_ast_node* parse_expression(int limit = 0)
                {
                        xpath_ast_node* n = parse_path_or_unary_expression();
                        if (!n) return 0;

                        return parse_expression_rec(n, limit);
                }

                xpath_parser(const char_t* query, xpath_variable_set* variables, xpath_allocator* alloc, xpath_parse_result* result): _alloc(alloc), _lexer(query), _query(query), _variables(variables), _result(result)
                {
                }

                xpath_ast_node* parse()
                {
                        xpath_ast_node* n = parse_expression();
                        if (!n) return 0;

                        // check if there are unparsed tokens left
                        if (_lexer.current() != lex_eof)
                                return error("Incorrect query");

                        return n;
                }

                static xpath_ast_node* parse(const char_t* query, xpath_variable_set* variables, xpath_allocator* alloc, xpath_parse_result* result)
                {
                        xpath_parser parser(query, variables, alloc, result);

                        return parser.parse();
                }
        };

        struct xpath_query_impl
        {
                static xpath_query_impl* create()
                {
                        void* memory = xml_memory::allocate(sizeof(xpath_query_impl));
                        if (!memory) return 0;

                        return new (memory) xpath_query_impl();
                }

                static void destroy(xpath_query_impl* impl)
                {
                        // free all allocated pages
                        impl->alloc.release();

                        // free allocator memory (with the first page)
                        xml_memory::deallocate(impl);
                }

                xpath_query_impl(): root(0), alloc(&block, &oom), oom(false)
                {
                        block.next = 0;
                        block.capacity = sizeof(block.data);
                }

                xpath_ast_node* root;
                xpath_allocator alloc;
                xpath_memory_block block;
                bool oom;
        };

        PUGI__FN impl::xpath_ast_node* evaluate_node_set_prepare(xpath_query_impl* impl)
        {
                if (!impl) return 0;

                if (impl->root->rettype() != xpath_type_node_set)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        return 0;
                #else
                        xpath_parse_result res;
                        res.error = "Expression does not evaluate to node set";

                        throw xpath_exception(res);
                #endif
                }

                return impl->root;
        }
PUGI__NS_END

namespace pugi
{
#ifndef PUGIXML_NO_EXCEPTIONS
        PUGI__FN xpath_exception::xpath_exception(const xpath_parse_result& result_): _result(result_)
        {
                assert(_result.error);
        }

        PUGI__FN const char* xpath_exception::what() const throw()
        {
                return _result.error;
        }

        PUGI__FN const xpath_parse_result& xpath_exception::result() const
        {
                return _result;
        }
#endif

        PUGI__FN xpath_node::xpath_node()
        {
        }

        PUGI__FN xpath_node::xpath_node(const xml_node& node_): _node(node_)
        {
        }

        PUGI__FN xpath_node::xpath_node(const xml_attribute& attribute_, const xml_node& parent_): _node(attribute_ ? parent_ : xml_node()), _attribute(attribute_)
        {
        }

        PUGI__FN xml_node xpath_node::node() const
        {
                return _attribute ? xml_node() : _node;
        }

        PUGI__FN xml_attribute xpath_node::attribute() const
        {
                return _attribute;
        }

        PUGI__FN xml_node xpath_node::parent() const
        {
                return _attribute ? _node : _node.parent();
        }

        PUGI__FN static void unspecified_bool_xpath_node(xpath_node***)
        {
        }

        PUGI__FN xpath_node::operator xpath_node::unspecified_bool_type() const
        {
                return (_node || _attribute) ? unspecified_bool_xpath_node : 0;
        }

        PUGI__FN bool xpath_node::operator!() const
        {
                return !(_node || _attribute);
        }

        PUGI__FN bool xpath_node::operator==(const xpath_node& n) const
        {
                return _node == n._node && _attribute == n._attribute;
        }

        PUGI__FN bool xpath_node::operator!=(const xpath_node& n) const
        {
                return _node != n._node || _attribute != n._attribute;
        }

#ifdef __BORLANDC__
        PUGI__FN bool operator&&(const xpath_node& lhs, bool rhs)
        {
                return (bool)lhs && rhs;
        }

        PUGI__FN bool operator||(const xpath_node& lhs, bool rhs)
        {
                return (bool)lhs || rhs;
        }
#endif

        PUGI__FN void xpath_node_set::_assign(const_iterator begin_, const_iterator end_, type_t type_)
        {
                assert(begin_ <= end_);

                size_t size_ = static_cast<size_t>(end_ - begin_);

                if (size_ <= 1)
                {
                        // deallocate old buffer
                        if (_begin != &_storage) impl::xml_memory::deallocate(_begin);

                        // use internal buffer
                        if (begin_ != end_) _storage = *begin_;

                        _begin = &_storage;
                        _end = &_storage + size_;
                        _type = type_;
                }
                else
                {
                        // make heap copy
                        xpath_node* storage = static_cast<xpath_node*>(impl::xml_memory::allocate(size_ * sizeof(xpath_node)));

                        if (!storage)
                        {
                        #ifdef PUGIXML_NO_EXCEPTIONS
                                return;
                        #else
                                throw std::bad_alloc();
                        #endif
                        }

                        memcpy(storage, begin_, size_ * sizeof(xpath_node));

                        // deallocate old buffer
                        if (_begin != &_storage) impl::xml_memory::deallocate(_begin);

                        // finalize
                        _begin = storage;
                        _end = storage + size_;
                        _type = type_;
                }
        }

#ifdef PUGIXML_HAS_MOVE
        PUGI__FN void xpath_node_set::_move(xpath_node_set& rhs) PUGIXML_NOEXCEPT
        {
                _type = rhs._type;
                _storage = rhs._storage;
                _begin = (rhs._begin == &rhs._storage) ? &_storage : rhs._begin;
                _end = _begin + (rhs._end - rhs._begin);

                rhs._type = type_unsorted;
                rhs._begin = &rhs._storage;
                rhs._end = rhs._begin;
        }
#endif

        PUGI__FN xpath_node_set::xpath_node_set(): _type(type_unsorted), _begin(&_storage), _end(&_storage)
        {
        }

        PUGI__FN xpath_node_set::xpath_node_set(const_iterator begin_, const_iterator end_, type_t type_): _type(type_unsorted), _begin(&_storage), _end(&_storage)
        {
                _assign(begin_, end_, type_);
        }

        PUGI__FN xpath_node_set::~xpath_node_set()
        {
                if (_begin != &_storage)
                        impl::xml_memory::deallocate(_begin);
        }

        PUGI__FN xpath_node_set::xpath_node_set(const xpath_node_set& ns): _type(type_unsorted), _begin(&_storage), _end(&_storage)
        {
                _assign(ns._begin, ns._end, ns._type);
        }

        PUGI__FN xpath_node_set& xpath_node_set::operator=(const xpath_node_set& ns)
        {
                if (this == &ns) return *this;

                _assign(ns._begin, ns._end, ns._type);

                return *this;
        }

#ifdef PUGIXML_HAS_MOVE
        PUGI__FN xpath_node_set::xpath_node_set(xpath_node_set&& rhs) PUGIXML_NOEXCEPT: _type(type_unsorted), _begin(&_storage), _end(&_storage)
        {
                _move(rhs);
        }

        PUGI__FN xpath_node_set& xpath_node_set::operator=(xpath_node_set&& rhs) PUGIXML_NOEXCEPT
        {
                if (this == &rhs) return *this;

                if (_begin != &_storage)
                        impl::xml_memory::deallocate(_begin);

                _move(rhs);

                return *this;
        }
#endif

        PUGI__FN xpath_node_set::type_t xpath_node_set::type() const
        {
                return _type;
        }

        PUGI__FN size_t xpath_node_set::size() const
        {
                return _end - _begin;
        }

        PUGI__FN bool xpath_node_set::empty() const
        {
                return _begin == _end;
        }

        PUGI__FN const xpath_node& xpath_node_set::operator[](size_t index) const
        {
                assert(index < size());
                return _begin[index];
        }

        PUGI__FN xpath_node_set::const_iterator xpath_node_set::begin() const
        {
                return _begin;
        }

        PUGI__FN xpath_node_set::const_iterator xpath_node_set::end() const
        {
                return _end;
        }

        PUGI__FN void xpath_node_set::sort(bool reverse)
        {
                _type = impl::xpath_sort(_begin, _end, _type, reverse);
        }

        PUGI__FN xpath_node xpath_node_set::first() const
        {
                return impl::xpath_first(_begin, _end, _type);
        }

        PUGI__FN xpath_parse_result::xpath_parse_result(): error("Internal error"), offset(0)
        {
        }

        PUGI__FN xpath_parse_result::operator bool() const
        {
                return error == 0;
        }

        PUGI__FN const char* xpath_parse_result::description() const
        {
                return error ? error : "No error";
        }

        PUGI__FN xpath_variable::xpath_variable(xpath_value_type type_): _type(type_), _next(0)
        {
        }

        PUGI__FN const char_t* xpath_variable::name() const
        {
                switch (_type)
                {
                case xpath_type_node_set:
                        return static_cast<const impl::xpath_variable_node_set*>(this)->name;

                case xpath_type_number:
                        return static_cast<const impl::xpath_variable_number*>(this)->name;

                case xpath_type_string:
                        return static_cast<const impl::xpath_variable_string*>(this)->name;

                case xpath_type_boolean:
                        return static_cast<const impl::xpath_variable_boolean*>(this)->name;

                default:
                        assert(false && "Invalid variable type"); // unreachable
                        return 0;
                }
        }

        PUGI__FN xpath_value_type xpath_variable::type() const
        {
                return _type;
        }

        PUGI__FN bool xpath_variable::get_boolean() const
        {
                return (_type == xpath_type_boolean) ? static_cast<const impl::xpath_variable_boolean*>(this)->value : false;
        }

        PUGI__FN double xpath_variable::get_number() const
        {
                return (_type == xpath_type_number) ? static_cast<const impl::xpath_variable_number*>(this)->value : impl::gen_nan();
        }

        PUGI__FN const char_t* xpath_variable::get_string() const
        {
                const char_t* value = (_type == xpath_type_string) ? static_cast<const impl::xpath_variable_string*>(this)->value : 0;
                return value ? value : PUGIXML_TEXT("");
        }

        PUGI__FN const xpath_node_set& xpath_variable::get_node_set() const
        {
                return (_type == xpath_type_node_set) ? static_cast<const impl::xpath_variable_node_set*>(this)->value : impl::dummy_node_set;
        }

        PUGI__FN bool xpath_variable::set(bool value)
        {
                if (_type != xpath_type_boolean) return false;

                static_cast<impl::xpath_variable_boolean*>(this)->value = value;
                return true;
        }

        PUGI__FN bool xpath_variable::set(double value)
        {
                if (_type != xpath_type_number) return false;

                static_cast<impl::xpath_variable_number*>(this)->value = value;
                return true;
        }

        PUGI__FN bool xpath_variable::set(const char_t* value)
        {
                if (_type != xpath_type_string) return false;

                impl::xpath_variable_string* var = static_cast<impl::xpath_variable_string*>(this);

                // duplicate string
                size_t size = (impl::strlength(value) + 1) * sizeof(char_t);

                char_t* copy = static_cast<char_t*>(impl::xml_memory::allocate(size));
                if (!copy) return false;

                memcpy(copy, value, size);

                // replace old string
                if (var->value) impl::xml_memory::deallocate(var->value);
                var->value = copy;

                return true;
        }

        PUGI__FN bool xpath_variable::set(const xpath_node_set& value)
        {
                if (_type != xpath_type_node_set) return false;

                static_cast<impl::xpath_variable_node_set*>(this)->value = value;
                return true;
        }

        PUGI__FN xpath_variable_set::xpath_variable_set()
        {
                for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
                        _data[i] = 0;
        }

        PUGI__FN xpath_variable_set::~xpath_variable_set()
        {
                for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
                        _destroy(_data[i]);
        }

        PUGI__FN xpath_variable_set::xpath_variable_set(const xpath_variable_set& rhs)
        {
                for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
                        _data[i] = 0;

                _assign(rhs);
        }

        PUGI__FN xpath_variable_set& xpath_variable_set::operator=(const xpath_variable_set& rhs)
        {
                if (this == &rhs) return *this;

                _assign(rhs);

                return *this;
        }

#ifdef PUGIXML_HAS_MOVE
        PUGI__FN xpath_variable_set::xpath_variable_set(xpath_variable_set&& rhs) PUGIXML_NOEXCEPT
        {
                for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
                {
                        _data[i] = rhs._data[i];
                        rhs._data[i] = 0;
                }
        }

        PUGI__FN xpath_variable_set& xpath_variable_set::operator=(xpath_variable_set&& rhs) PUGIXML_NOEXCEPT
        {
                for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
                {
                        _destroy(_data[i]);

                        _data[i] = rhs._data[i];
                        rhs._data[i] = 0;
                }

                return *this;
        }
#endif

        PUGI__FN void xpath_variable_set::_assign(const xpath_variable_set& rhs)
        {
                xpath_variable_set temp;

                for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
                        if (rhs._data[i] && !_clone(rhs._data[i], &temp._data[i]))
                                return;

                _swap(temp);
        }

        PUGI__FN void xpath_variable_set::_swap(xpath_variable_set& rhs)
        {
                for (size_t i = 0; i < sizeof(_data) / sizeof(_data[0]); ++i)
                {
                        xpath_variable* chain = _data[i];

                        _data[i] = rhs._data[i];
                        rhs._data[i] = chain;
                }
        }

        PUGI__FN xpath_variable* xpath_variable_set::_find(const char_t* name) const
        {
                const size_t hash_size = sizeof(_data) / sizeof(_data[0]);
                size_t hash = impl::hash_string(name) % hash_size;

                // look for existing variable
                for (xpath_variable* var = _data[hash]; var; var = var->_next)
                        if (impl::strequal(var->name(), name))
                                return var;

                return 0;
        }

        PUGI__FN bool xpath_variable_set::_clone(xpath_variable* var, xpath_variable** out_result)
        {
                xpath_variable* last = 0;

                while (var)
                {
                        // allocate storage for new variable
                        xpath_variable* nvar = impl::new_xpath_variable(var->_type, var->name());
                        if (!nvar) return false;

                        // link the variable to the result immediately to handle failures gracefully
                        if (last)
                                last->_next = nvar;
                        else
                                *out_result = nvar;

                        last = nvar;

                        // copy the value; this can fail due to out-of-memory conditions
                        if (!impl::copy_xpath_variable(nvar, var)) return false;

                        var = var->_next;
                }

                return true;
        }

        PUGI__FN void xpath_variable_set::_destroy(xpath_variable* var)
        {
                while (var)
                {
                        xpath_variable* next = var->_next;

                        impl::delete_xpath_variable(var->_type, var);

                        var = next;
                }
        }

        PUGI__FN xpath_variable* xpath_variable_set::add(const char_t* name, xpath_value_type type)
        {
                const size_t hash_size = sizeof(_data) / sizeof(_data[0]);
                size_t hash = impl::hash_string(name) % hash_size;

                // look for existing variable
                for (xpath_variable* var = _data[hash]; var; var = var->_next)
                        if (impl::strequal(var->name(), name))
                                return var->type() == type ? var : 0;

                // add new variable
                xpath_variable* result = impl::new_xpath_variable(type, name);

                if (result)
                {
                        result->_next = _data[hash];

                        _data[hash] = result;
                }

                return result;
        }

        PUGI__FN bool xpath_variable_set::set(const char_t* name, bool value)
        {
                xpath_variable* var = add(name, xpath_type_boolean);
                return var ? var->set(value) : false;
        }

        PUGI__FN bool xpath_variable_set::set(const char_t* name, double value)
        {
                xpath_variable* var = add(name, xpath_type_number);
                return var ? var->set(value) : false;
        }

        PUGI__FN bool xpath_variable_set::set(const char_t* name, const char_t* value)
        {
                xpath_variable* var = add(name, xpath_type_string);
                return var ? var->set(value) : false;
        }

        PUGI__FN bool xpath_variable_set::set(const char_t* name, const xpath_node_set& value)
        {
                xpath_variable* var = add(name, xpath_type_node_set);
                return var ? var->set(value) : false;
        }

        PUGI__FN xpath_variable* xpath_variable_set::get(const char_t* name)
        {
                return _find(name);
        }

        PUGI__FN const xpath_variable* xpath_variable_set::get(const char_t* name) const
        {
                return _find(name);
        }

        PUGI__FN xpath_query::xpath_query(const char_t* query, xpath_variable_set* variables): _impl(0)
        {
                impl::xpath_query_impl* qimpl = impl::xpath_query_impl::create();

                if (!qimpl)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        _result.error = "Out of memory";
                #else
                        throw std::bad_alloc();
                #endif
                }
                else
                {
                        using impl::auto_deleter; // MSVC7 workaround
                        auto_deleter<impl::xpath_query_impl> impl(qimpl, impl::xpath_query_impl::destroy);

                        qimpl->root = impl::xpath_parser::parse(query, variables, &qimpl->alloc, &_result);

                        if (qimpl->root)
                        {
                                qimpl->root->optimize(&qimpl->alloc);

                                _impl = impl.release();
                                _result.error = 0;
                        }
                        else
                        {
                        #ifdef PUGIXML_NO_EXCEPTIONS
                                if (qimpl->oom) _result.error = "Out of memory";
                        #else
                                if (qimpl->oom) throw std::bad_alloc();
                                throw xpath_exception(_result);
                        #endif
                        }
                }
        }

        PUGI__FN xpath_query::xpath_query(): _impl(0)
        {
        }

        PUGI__FN xpath_query::~xpath_query()
        {
                if (_impl)
                        impl::xpath_query_impl::destroy(static_cast<impl::xpath_query_impl*>(_impl));
        }

#ifdef PUGIXML_HAS_MOVE
        PUGI__FN xpath_query::xpath_query(xpath_query&& rhs) PUGIXML_NOEXCEPT
        {
                _impl = rhs._impl;
                _result = rhs._result;
                rhs._impl = 0;
                rhs._result = xpath_parse_result();
        }

        PUGI__FN xpath_query& xpath_query::operator=(xpath_query&& rhs) PUGIXML_NOEXCEPT
        {
                if (this == &rhs) return *this;

                if (_impl)
                        impl::xpath_query_impl::destroy(static_cast<impl::xpath_query_impl*>(_impl));

                _impl = rhs._impl;
                _result = rhs._result;
                rhs._impl = 0;
                rhs._result = xpath_parse_result();

                return *this;
        }
#endif

        PUGI__FN xpath_value_type xpath_query::return_type() const
        {
                if (!_impl) return xpath_type_none;

                return static_cast<impl::xpath_query_impl*>(_impl)->root->rettype();
        }

        PUGI__FN bool xpath_query::evaluate_boolean(const xpath_node& n) const
        {
                if (!_impl) return false;

                impl::xpath_context c(n, 1, 1);
                impl::xpath_stack_data sd;

                bool r = static_cast<impl::xpath_query_impl*>(_impl)->root->eval_boolean(c, sd.stack);

                if (sd.oom)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        return false;
                #else
                        throw std::bad_alloc();
                #endif
                }

                return r;
        }

        PUGI__FN double xpath_query::evaluate_number(const xpath_node& n) const
        {
                if (!_impl) return impl::gen_nan();

                impl::xpath_context c(n, 1, 1);
                impl::xpath_stack_data sd;

                double r = static_cast<impl::xpath_query_impl*>(_impl)->root->eval_number(c, sd.stack);

                if (sd.oom)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        return impl::gen_nan();
                #else
                        throw std::bad_alloc();
                #endif
                }

                return r;
        }

#ifndef PUGIXML_NO_STL
        PUGI__FN string_t xpath_query::evaluate_string(const xpath_node& n) const
        {
                if (!_impl) return string_t();

                impl::xpath_context c(n, 1, 1);
                impl::xpath_stack_data sd;

                impl::xpath_string r = static_cast<impl::xpath_query_impl*>(_impl)->root->eval_string(c, sd.stack);

                if (sd.oom)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        return string_t();
                #else
                        throw std::bad_alloc();
                #endif
                }

                return string_t(r.c_str(), r.length());
        }
#endif

        PUGI__FN size_t xpath_query::evaluate_string(char_t* buffer, size_t capacity, const xpath_node& n) const
        {
                impl::xpath_context c(n, 1, 1);
                impl::xpath_stack_data sd;

                impl::xpath_string r = _impl ? static_cast<impl::xpath_query_impl*>(_impl)->root->eval_string(c, sd.stack) : impl::xpath_string();

                if (sd.oom)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        r = impl::xpath_string();
                #else
                        throw std::bad_alloc();
                #endif
                }

                size_t full_size = r.length() + 1;

                if (capacity > 0)
                {
                        size_t size = (full_size < capacity) ? full_size : capacity;
                        assert(size > 0);

                        memcpy(buffer, r.c_str(), (size - 1) * sizeof(char_t));
                        buffer[size - 1] = 0;
                }

                return full_size;
        }

        PUGI__FN xpath_node_set xpath_query::evaluate_node_set(const xpath_node& n) const
        {
                impl::xpath_ast_node* root = impl::evaluate_node_set_prepare(static_cast<impl::xpath_query_impl*>(_impl));
                if (!root) return xpath_node_set();

                impl::xpath_context c(n, 1, 1);
                impl::xpath_stack_data sd;

                impl::xpath_node_set_raw r = root->eval_node_set(c, sd.stack, impl::nodeset_eval_all);

                if (sd.oom)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        return xpath_node_set();
                #else
                        throw std::bad_alloc();
                #endif
                }

                return xpath_node_set(r.begin(), r.end(), r.type());
        }

        PUGI__FN xpath_node xpath_query::evaluate_node(const xpath_node& n) const
        {
                impl::xpath_ast_node* root = impl::evaluate_node_set_prepare(static_cast<impl::xpath_query_impl*>(_impl));
                if (!root) return xpath_node();

                impl::xpath_context c(n, 1, 1);
                impl::xpath_stack_data sd;

                impl::xpath_node_set_raw r = root->eval_node_set(c, sd.stack, impl::nodeset_eval_first);

                if (sd.oom)
                {
                #ifdef PUGIXML_NO_EXCEPTIONS
                        return xpath_node();
                #else
                        throw std::bad_alloc();
                #endif
                }

                return r.first();
        }

        PUGI__FN const xpath_parse_result& xpath_query::result() const
        {
                return _result;
        }

        PUGI__FN static void unspecified_bool_xpath_query(xpath_query***)
        {
        }

        PUGI__FN xpath_query::operator xpath_query::unspecified_bool_type() const
        {
                return _impl ? unspecified_bool_xpath_query : 0;
        }

        PUGI__FN bool xpath_query::operator!() const
        {
                return !_impl;
        }

        PUGI__FN xpath_node xml_node::select_node(const char_t* query, xpath_variable_set* variables) const
        {
                xpath_query q(query, variables);
                return q.evaluate_node(*this);
        }

        PUGI__FN xpath_node xml_node::select_node(const xpath_query& query) const
        {
                return query.evaluate_node(*this);
        }

        PUGI__FN xpath_node_set xml_node::select_nodes(const char_t* query, xpath_variable_set* variables) const
        {
                xpath_query q(query, variables);
                return q.evaluate_node_set(*this);
        }

        PUGI__FN xpath_node_set xml_node::select_nodes(const xpath_query& query) const
        {
                return query.evaluate_node_set(*this);
        }

        PUGI__FN xpath_node xml_node::select_single_node(const char_t* query, xpath_variable_set* variables) const
        {
                xpath_query q(query, variables);
                return q.evaluate_node(*this);
        }

        PUGI__FN xpath_node xml_node::select_single_node(const xpath_query& query) const
        {
                return query.evaluate_node(*this);
        }
}

#endif

#ifdef __BORLANDC__
#       pragma option pop
#endif

// Intel C++ does not properly keep warning state for function templates,
// so popping warning state at the end of translation unit leads to warnings in the middle.
#if defined(_MSC_VER) && !defined(__INTEL_COMPILER)
#       pragma warning(pop)
#endif

#if defined(_MSC_VER) && defined(__c2__)
#       pragma clang diagnostic pop
#endif

// Undefine all local macros (makes sure we're not leaking macros in header-only mode)
#undef PUGI__NO_INLINE
#undef PUGI__UNLIKELY
#undef PUGI__STATIC_ASSERT
#undef PUGI__DMC_VOLATILE
#undef PUGI__UNSIGNED_OVERFLOW
#undef PUGI__MSVC_CRT_VERSION
#undef PUGI__SNPRINTF
#undef PUGI__NS_BEGIN
#undef PUGI__NS_END
#undef PUGI__FN
#undef PUGI__FN_NO_INLINE
#undef PUGI__GETHEADER_IMPL
#undef PUGI__GETPAGE_IMPL
#undef PUGI__GETPAGE
#undef PUGI__NODETYPE
#undef PUGI__IS_CHARTYPE_IMPL
#undef PUGI__IS_CHARTYPE
#undef PUGI__IS_CHARTYPEX
#undef PUGI__ENDSWITH
#undef PUGI__SKIPWS
#undef PUGI__OPTSET
#undef PUGI__PUSHNODE
#undef PUGI__POPNODE
#undef PUGI__SCANFOR
#undef PUGI__SCANWHILE
#undef PUGI__SCANWHILE_UNROLL
#undef PUGI__ENDSEG
#undef PUGI__THROW_ERROR
#undef PUGI__CHECK_ERROR

#endif

/**
 * Copyright (c) 2006-2018 Arseny Kapoulkine
 *
 * Permission is hereby granted, free of charge, to any person
 * obtaining a copy of this software and associated documentation
 * files (the "Software"), to deal in the Software without
 * restriction, including without limitation the rights to use,
 * copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following
 * conditions:
 *
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
 * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
 * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
 * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
 * OTHER DEALINGS IN THE SOFTWARE.
 */