----- Mensaje original ----- De: Robert Ramey <ramey@rrsd.com> Fecha: Martes, Enero 25, 2005 10:33 pm Asunto: [boost] Re: [Serialization] of pointers into a vector

This is a currently known problem with the library. It only became apparrent with the implementation of serialization for indexed set.

The problem arises because the objects are deserialized to a temporary variable then moved into the collection. So the pointers are not going to point to objects final resting place.

This can be circumvented if one's willing to accept making intrusive changes to the element type. The following is a sketch of the tecnhique (caveat, not compiled): template<typename Derived> class retrackable { private: friend class boost::serialization::access; template<class Archive> void serialize(Archive&,const unsigned int) { // do nothing } }; class object:public retrackable<object> { ... template<class Archive> void serialize(Archive&,const unsigned int) { // serialize as usual } } class foo { private: std::vector<object> v; object* po; // po points to some element of v friend class boost::serialization::access; BOOST_SERIALIZATION_SPLIT_MEMBER() template<class Archive> void save(Archive& ar,const unsigned int version)const { ar<<v; for(std::vector<object>::const_iterator it=v.begin(),it_end=v.end(); it!=it_end;++it){ ar<<static_cast<const retrackable<object>&>(*it); } ar<<static_cast<retrackable<object>*>(po); } template<class Archive> void load(Archive& ar,const unsigned int version) { ar>>v; for(std::vector<object>::iterator it=v.begin(),it_end=v.end(); it!=it_end;++it){ ar>>static_cast<retrackable<object>&>(*it); } retrackable<object>* pro; ar>>pro; po=static_cast<object*>(pro); } }; Of course, an extension to Boost.Serialization would be better --something along a facility to instruct the serialization lib to change the tracking address of an object when this is moved around. HTH, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo