Serializing polymorphic class using boost

Question

When i try to serilize data where Sphere is subclass of geometry the program crashes with unhandled exception.

Exception thrown at 0x000007FEFCA0B87D in Serialization.exe: Microsoft C++ exception: boost::archive::archive_exception at memory location 0x000000000022F730

This happens on this line "ar & g ;"

include "pch.h"
#include <iostream>
#include<fstream>
#include <boost/archive/text_iarchive.hpp>
#include <boost/archive/text_oarchive.hpp>
#include "Geometry.h"
#include "Sphere.h"
#include <boost/serialization/export.hpp>


int main()
{
    const char* fileName = "saved.txt";

    Sphere Sph;
    Geometry* g = &Sph;

    // save data
    {
        // Create an output archive
        std::ofstream ofs(fileName);        
        boost::archive::text_oarchive ar(ofs);  
        ar & g ;    // This lines throws exception.     
    }
    Geometry* c_Restored;   
    //load data
    {
        // create an input stream
        std::ifstream ifs(fileName);        
        boost::archive::text_iarchive ar(ifs);
        ar & c_Restored;
    }


    c_Restored->PrintGeom();

    do
    {
        std::cout << '\n' << "Press a key to continue...";
    } while (std::cin.get() != '\n');
}

/////////////////////////////////////////////////////////////////////

#include "Geometry.h"
#include <boost/serialization/serialization.hpp>
#include <boost/serialization/export.hpp>




class Sphere : public Geometry
{
private:
    std::string stdstrSphere;


public:
    Sphere() : stdstrSphere( "DefaultSphere"){}
    Sphere( std::string str) : stdstrSphere(str) {}
    void PrintGeom()
    {
        std::cout << "Sphere Virtual Function" << std::endl;
    }

private:
    typedef Geometry _Super;
    friend class boost::serialization::access;


    template <typename Archive>
    void save(Archive& ar, const unsigned version) const {

        boost::serialization::base_object<_Super>(*this);
        ar & stdstrSphere;
    }

    template <typename Archive>
    void load(Archive& ar, const unsigned version) {

        boost::serialization::base_object<_Super>(*this);
        ar & stdstrSphere;
    }

    BOOST_SERIALIZATION_SPLIT_MEMBER()



};

///////////////////////////////////////////////////////////////////////////// #pragma once

#include <string>
#include <boost/serialization/split_member.hpp>
#include <boost/serialization/base_object.hpp>

class Geometry
{
private:
    std::string stdstringGeom;

public:
     virtual void  PrintGeom()
    {
        std::cout << "geometry virtual function";
    }

private:

    friend class boost::serialization::access;


    template <typename Archive>
    void save(Archive& ar, const unsigned version) const {
        ar & stdstringGeom;
    }

    template <typename Archive>
    void load(Archive& ar, const unsigned version) {
        ar & stdstringGeom;
    }


    BOOST_SERIALIZATION_SPLIT_MEMBER()
};

score 1 · Accepted Answer · answered Sep 13 '19 at 11:01

1

When I compile and run the code shown the exception text is...

unregistered class - derived class not registered or exported

So the underlying problem is that you need to register your derived class(es) as outlined here. Try adding the following just before main...

BOOST_CLASS_EXPORT_GUID(Sphere, "Sphere")

answered Sep 13 '19 at 11:01

G.M.

12,232
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18

Just happened to post this answer which is a treasure trove of examples in varying complexity - there's much subtlety surrounding the ordering of includes and position of the EXPORT macros (e.g. when separating translation units): https://stackoverflow.com/questions/57967663/where-to-declare-boost-class-export-for-serialization/58000691#58000691 – sehe Sep 18 '19 at 21:30

Serializing polymorphic class using boost

1 Answers1