问如何使用std::shared_ptr进行boost：：序列化工作？

EN

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

#include <fstream>
#include <memory>
#include <vector>

class A
{
public:
    std::shared_ptr<int> v;

    void A::Save(char * const filename);
    static A * const Load(char * const filename);

        //////////////////////////////////
        // Boost Serialization:
        //
    private:
        friend class boost::serialization::access;
        template<class Archive> void serialize(Archive & ar, const unsigned int file_version) 
        {
            ar & v;
        }
};

// save the world to a file:
void A::Save(char * const filename)
{
    // create and open a character archive for output
    std::ofstream ofs(filename);

    // save data to archive
    {
        boost::archive::text_oarchive oa(ofs);

        // write the pointer to file
        oa << this;
    }
}

// load world from file
A * const A::Load(char * const filename)
{
    A * a;

    // create and open an archive for input
    std::ifstream ifs(filename);

    boost::archive::text_iarchive ia(ifs);

    // read class pointer from archive
    ia >> a;

    return a;
}

int main()
{

}