--- /dev/null
+#pragma once
+
+#include <boost/variant/static_visitor.hpp>
+
+#include "mstch/mstch.hpp"
+
+namespace mstch {
+
+class is_node_empty: public boost::static_visitor<bool> {
+ public:
+ template<class T>
+ bool operator()(const T&) const {
+ return false;
+ }
+
+ bool operator()(const std::nullptr_t&) const {
+ return true;
+ }
+
+ bool operator()(const int& value) const {
+ return value == 0;
+ }
+
+ bool operator()(const double& value) const {
+ return value == 0;
+ }
+
+ bool operator()(const bool& value) const {
+ return !value;
+ }
+
+ bool operator()(const std::string& value) const {
+ return value == "";
+ }
+
+ bool operator()(const array& array) const {
+ return array.size() == 0;
+ }
+};
+
+}