Any tipps on writing a copy constructor when copying a member from a third party module is denied?

Question

I am currently writing some code that shall read data from an xml file. To this end I use the pugixml module that offes a class xml_document providing methods to parse the file. To store this data I have created a class tXmlDoc that manages loading operations (like setting path, storing the parse result and so forth). I now wanted to include a copy constructor to this tXmlDoc but, alas, I cannot copy the pugi::xml_document member as pugixml apparantly explicitely denies copying as far as I understand the code of this module.

What would be your advice how to handle this? I would not like to write a copy constructor for pugixml as I am certain that the author has good reasons to deny this and I would not like to fiddle with that.

BTW, I have a similiar issue with the assignment operator.

As it seems only a move constructor is implemented in pugixml.

Here's my current tXmlDoc header.

#pragma once

#include <iostream>
#include <string>
#include <array>
#include "../../libs/pugixml-1.11/src/pugixml.hpp"
#include "XmlData_General.h"
#include "XmlNodes.h"

namespace nXml
{
    /**
    * This class provides methods and helper functions to:
    * - read an xml file identified by its file name including suffix and the path to this file
    * - load the root node of the xml document
    * - to manage basic information of the root node
    */
    class tXmlDoc
    {
    public:
        tXmlDoc();
        tXmlDoc(tXmlDoc&); //copy constructor

        ~tXmlDoc();

        tXmlDoc& operator=(const tXmlDoc&);

        void LoadXmlFile(const std::string& file_name, std::string& file_path);

        pugi::xml_node GetRootNode();

        std::string GetFileName();
        std::string GetFilePath();
        std::string GetFullPath(const std::string& file_name, std::string& file_path); 

        void SetFileName(const std::string& file_name);
        void SetFilePath(const std::string& file_path);

        bool GetFileLoaded();
        bool GetNodeCorrect();

        int GetErrorCode();
        int GetChildNumber();

        pugi::xml_parse_result GetXmlResult();

        void LoadData();
        void CheckNode();

    protected:
        std::string file_path = ""; //is set when calling LoadXmlFile
        std::string file_name = ""; //is set when calling LoadXmlFile

        bool file_loaded = false; //provides information is file was successfully loaded (file correctly loaded: true). Modified by method LoadXmlFile
        bool node_correct = false; //indicating of node structure on its child level is correct

        int error_code = 0; //provides information about occuring errors (no error: 0). Modified by method LoadXmlFile

        int n_childs = 0;

        pugi::xml_node root_node = pugi::xml_node(); //contains the root node of the xml document. Filled when calling LoadData (via calling GetRootNode inside LoadData)
        pugi::xml_parse_result xml_result; //contains information about parsing result. Filled by method LoadXmlFile    
        pugi::xml_document xml_doc; //contains the entire document

        //make sNodeNames known
        sXmlNodeNames sNodeNames;
    }
    ;

};

score 1 · Accepted Answer · answered Mar 20 '21 at 10:42

1

Is it possible to copy it manually:

I found this question on the subject

xml_document copy;
copy.reset(doc);

Another option if you do not want to really copy it is to keep a shared_ptr to a const version of the xml-root.

answered Mar 20 '21 at 10:42

Lasersköld

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Any tipps on writing a copy constructor when copying a member from a third party module is denied?

1 Answers1