Memo on Boost Serialization & Asio

register_type() is required on building a polymorphic pointer from oarchive. In my situation, BOOST_CLASS_EXPORT and BOOST_CLASS_EXPORT_GUID are no effects. Why is unknown..

And, some typical bugs occur;

• such polymorphic pointer requires virtual destructor.
• Because the operator << of iostream deals string, zero value is not written.

These are easy mistake.