[Boost-users] [serialization] polymorphic archives in dlls and pointer to derived problems

Subject: [Boost-users] [serialization] polymorphic archives in dlls and pointer to derived problems
From: Kolb, Jeremy (jkolb_at_[hidden])
Date: 2011-01-04 11:13:39

I'm having a lot of trouble getting serialization of derived classes
through a base pointer working across dlls.  I have the following:

 

DLL (data_types.dll) code:

 

stdafx.h:

#pragma once

 

#include "targetver.h"

 

#define WIN32_LEAN_AND_MEAN             // Exclude rarely-used stuff
from Windows headers

// Windows Header Files:

#include <windows.h>

 

#pragma warning(disable: 4308)

#include "boost/archive/polymorphic_iarchive.hpp"

#include "boost/archive/polymorphic_oarchive.hpp"

#include "boost/serialization/nvp.hpp"

 

Base.h:

#pragma once

#include "boost/serialization/export.hpp"

class __declspec(dllexport) Base

{

    friend class boost::serialization::access;

    template<class Archive> void serialize(Archive& ar, const unsigned
int version);

    

public:

    Base() {}

    virtual ~Base() {}

    int i;

};

 

BOOST_SERIALIZATION_ASSUME_ABSTRACT(Base); // Doesn't make a difference.

BOOST_CLASS_EXPORT_KEY(Base);

 

Base.cpp:

#include "stdafx.h"

#include "Base.h"

 

template<class Archive>

void Base::serialize(Archive& ar, const unsigned int version)

{

    ar & BOOST_SERIALIZATION_NVP(i);

}

 

BOOST_CLASS_EXPORT_IMPLEMENT(Base);

template void __declspec(dllexport)
Base::serialize(boost::archive::polymorphic_iarchive& ar, const unsigned
int version);

template void __declspec(dllexport)
Base::serialize(boost::archive::polymorphic_oarchive& ar, const unsigned
int version);

 

Derived.h:

#include "Base.h"

 

class __declspec(dllexport) Derived : public Base

{

    friend class boost::serialization::access;

    template<class Archive> void serialize(Archive& ar, const unsigned
int version);

 

public:

    Derived() {}

    Derived(int num) : j(num) {}

    int j;

};

 

BOOST_CLASS_EXPORT_KEY(Derived);

 

Derived.cpp:

#include "stdafx.h"

#include "Derived.h"

 

template<class Archive>

void Derived::serialize(Archive& ar, const unsigned int version)

{

    ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base);

    ar & BOOST_SERIALIZATION_NVP(j);

}

 

BOOST_CLASS_EXPORT_IMPLEMENT(Derived);

template void __declspec(dllexport)
Derived::serialize(boost::archive::polymorphic_iarchive& ar, const
unsigned int version);

template void __declspec(dllexport)
Derived::serialize(boost::archive::polymorphic_oarchive& ar, const
unsigned int version);

 

My exe links against the DLL and contains the following:

 

#include "stdafx.h"

#include "boost/archive/polymorphic_xml_iarchive.hpp"

#include "boost/archive/polymorphic_xml_oarchive.hpp"

 

#include "data_types/Derived.h"

#include <fstream>

 

int _tmain(int argc, _TCHAR* argv[])

{

    std::ofstream f("c:\\test.xml");

    boost::archive::polymorphic_xml_oarchive xml(f);

    

    Base* b = new Derived(123);

    xml & BOOST_SERIALIZATION_NVP(b);

    

    delete b;

    

      return 0;

}

 

When serializing this fails with unregistered_class even though I export
both Base and Derived.

 

Jeremy