-size_t my_fread(void *ptr, size_t size, size_t nmemb, ostream *stream);
+int my_fseekr(istream *stream, long offset, int whence);
+size_t my_fread(void *ptr, size_t size, size_t nmemb, istream *stream);
+size_t my_fwrite(const void *ptr, size_t size, size_t nmemb, ostream *stream);