#include <fstream>

#include <boost/serialization/serialization.hpp>

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

#include <boost/serialization/string.hpp>

#include <boost/serialization/access.hpp>
#include <boost/serialization/nvp.hpp>

struct MyString {
	std::string s_;
};


namespace boost {
namespace serialization {

template<class Archive>
void
serialize(Archive& ar, MyString& ms, unsigned int const /*version*/)
{
	ar & ms.s_;
}

} // namespace serialization
} // namespace boost

#if 1
typedef boost::archive::xml_oarchive oarchive;
typedef boost::archive::xml_iarchive iarchive;
//BOOST_CLASS_IS_WRAPPER(std::string) // Why is it required?
#else
typedef boost::archive::text_oarchive oarchive;
typedef boost::archive::text_iarchive iarchive;
#endif


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

int main()
{
	{
		Model m;
		std::ofstream ofs("foo.xml");
		oarchive oa(ofs);
		oa << boost::serialization::make_nvp("Model", m);
	}
	{
		Model m;
		std::ifstream ifs("foo.xml");
		iarchive ia(ifs);
		ia >> boost::serialization::make_nvp("Model", m);
	}
}