[Boost-users] How to serialize a derived class object with base class pointer?

Hi, I'm trying to serialize an object of derived class with a base class pointer, somehow only base class's serialization member function got called. Here is the code (simplified): class CMyCls1 { public: CMyCls1() : m(10) {} ~CMyCls1() {} private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(m); } int m; }; class CMyCls2 : public CMyCls1 { public: CMyCls2() : x(1.5) {} ~CMyCls2() {} private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(CMyCls1); ar & BOOST_SERIALIZATION_NVP(x); } double x; }; void main () { CMyCls1 *pmycls = new CMyCls2; ... oa.register_type(static_cast(NULL)); oa.register_type(static_cast(NULL)); oa << BOOST_SERIALIZATION_NVP(pmycls); ... } Look at the archive file, only base class data is serialized. Actuall, CMyCls2::serialization() is not called at all. How do you serialize a derived class object with a pointer of base class? Thanks, Yan