visual c++ - RapidXML saving into a File -

i have googled , have problem saving xml_document<> doc in .xml file. code shall save chess games notations xml file put in compressed file adding multimedia files it. can add audio comments every game stored in xml.

#ifndef _filereader_hpp #define _file_reader_hpp  #include<fstream> #include"rapidxml.hpp" #include"notation.h"   namespace pgnx {     class filewriter     {         std::map<unsigned int, tournament> data;         std::ofstream file;         std::string fn;         rapidxml::xml_document<> doc;     protected:         void save();     public:         filewriter(char* filename);         filewriter();         ~filewriter(){}         void prepare();         void inserttournament(tournament);         //operators         filewriter& operator+(tournament rhs);         filewriter& operator=(std::map<unsigned int, tournament> rhs);         filewriter& operator=(pgnx::filewriter rhs);         tournament& operator[](unsigned int index);     }; }  #endif 

and functions

void filewriter::prepare() {     using namespace rapidxml;     xml_node<>* decl = doc.allocate_node(node_declaration);     decl->append_attribute(doc.allocate_attribute("version", "1.0"));     decl->append_attribute(doc.allocate_attribute("encoding", "utf-8"));     doc.append_node(decl);      xml_node<>* pgnx = doc.allocate_node(node_element, "pgnx");     pgnx->append_attribute(doc.allocate_attribute("version", _version_));     doc.append_node(pgnx);      (unsigned int = 0; < this->data.rbegin()->first + 1; i++)     {         xml_node<>* child = doc.allocate_node(node_element, "tournament");         child->append_attribute(doc.allocate_attribute("id", (const char*)i));         child->append_attribute(doc.allocate_attribute("name", me[i].getname()));         (unsigned int j = 0; j < me[i].getlength(); j++)         {             xml_node<>* game = doc.allocate_node(node_element, "game");             game->append_attribute(doc.allocate_attribute("white", (me[i])[j].getnamew()));             game->append_attribute(doc.allocate_attribute("black", (me[i])[j].getnameb()));             game->append_attribute(doc.allocate_attribute("result", (const char*)(me[i])[j].getresult()));             (unsigned int k = 0; k < (me[i])[j].getlength(); k++)             {                 xml_node<>* move = doc.allocate_node(node_element, "move");                 move->append_attribute(doc.allocate_attribute("number", (const char*)k));                 move->append_attribute(doc.allocate_attribute("white", ((me[i])[j])[k].getmovew()));                 move->append_attribute(doc.allocate_attribute("white", ((me[i])[j])[k].getmoveb()));                 game->append_node(move);             }             child->append_node(game);         }         pgnx->append_node(child);     }      this->file.open(fn.c_str());      this->save();       file.close();     doc.clear(); } 

and here problem:

void filewriter::save() {     file << this->doc.value();     file.close(); } 

i have tried file<<this->doc;but msvc threw error , marked operator<< error. tried google , looked other questions in stack overflow rapidxml, haven't found satisfying solution.

see manual: convert dom tree 'normal' xml, you'll need methods/operators defined in rapidxml_print.hpp

#include "rapidxml_print.hpp" 

then should able this, example.

rapidxml::xml_document<> doc; ... file << doc; 

(also, avoid this->. need in pretty rare circumstances)