[Boost-users] [serialization] assert when serializing polymorphic type to XML (Visual Studio 8)

4 Jan 2006

      I have condensed a short example which is appended to this message. The code
tries to write then read a polymorphic class via a base pointer. The
assertion I am seeing is assert(NULL != bpos_ptr); in oserializer.hpp. The
documentation indicates that the problem is likely a lack of registration of
the class, however, I have done this. Interestingly the code only fails for
XML archive type.

// BoostPolymorphicSerialize.cpp : Defines the entry point for the console
application.
//

#include <stdio.h>
#include <tchar.h>

#include <iomanip>
#include <iostream>
#include <fstream>
#include <string>

#include <boost/archive/tmpdir.hpp>

#include <boost/archive/text_iarchive.hpp>
#include <boost/archive/text_oarchive.hpp>

#include <boost/serialization/base_object.hpp>
#include <boost/serialization/utility.hpp>
#include <boost/serialization/list.hpp>
#include <boost/serialization/export.hpp>

#include <boost/shared_ptr.hpp>
#include <boost/shared_array.hpp>
#include <boost/serialization/shared_ptr.hpp>

#include "boost/archive/xml_iarchive.hpp"
#include "boost/archive/xml_oarchive.hpp"

class CMyBaseClass
{
public:
	CMyBaseClass(void):m_BaseValue(0){}
public:
	virtual ~CMyBaseClass(void){}
	int m_BaseValue;

	friend class boost::serialization::access;
	template<class Archive> void serialize(Archive & ar, const unsigned
int /* file_version */)
	{
		ar & BOOST_SERIALIZATION_NVP(m_BaseValue);
	}
};

class CMyDerivedClass : public CMyBaseClass
{
public:
	CMyDerivedClass(void):m_DerivedValue(1){}
public:
	~CMyDerivedClass(void){}
	int m_DerivedValue;

	friend class boost::serialization::access;
	template<class Archive> void serialize(Archive & ar, const unsigned
int /* file_version */)
	{
		BOOST_SERIALIZATION_BASE_OBJECT_NVP(CMyBaseClass);
		ar & BOOST_SERIALIZATION_NVP(m_DerivedValue);
	}
};

BOOST_CLASS_EXPORT_GUID(CMyBaseClass, "CMyBaseClass")
BOOST_CLASS_EXPORT_GUID(CMyDerivedClass, "CMyDerivedClass")

int _tmain(int argc, _TCHAR* argv[])
{
	const CMyBaseClass* const pMyBaseClass=new CMyDerivedClass();
	const std::string fileName("c:\\docs\\BoostSerializeTest.xml");
	CMyBaseClass* pMyBaseClass2=0;

	try
	{
		{
			std::ofstream ofs(fileName.c_str());
			assert(ofs.good());
			boost::archive::xml_oarchive oa(ofs);
			//boost::archive::text_oarchive oa(ofs);
			oa << BOOST_SERIALIZATION_NVP(pMyBaseClass);
		}

		{
			std::ifstream ifs(fileName.c_str());
			assert(ifs.good());
			boost::archive::xml_iarchive ia(ifs);
			//boost::archive::text_iarchive ia(ifs);
			ia >> BOOST_SERIALIZATION_NVP(pMyBaseClass2);
		}
	}
	catch(std::exception& e)
	{
		std::cout << e.what() << std::endl;
	}

	delete pMyBaseClass;
	delete pMyBaseClass2;

	return 0;
}

[Boost-users] [serialization] assert when serializing polymorphic type to XML (Visual Studio 8)

Terence Wilson