On Jul 14, 2008, at 5:40 PM, Steve Sanders wrote:
Thank you, that makes my sample work. These points could be clearer in the docs, I would say.
From: boost-users-bounces@lists.boost.org [mailto:boost-users- bounces@lists.boost.org] On Behalf Of Robert Ramey Sent: Monday, July 14, 2008 2:54 PM To: boost-users@lists.boost.org Subject: Re: [Boost-users] [serialization] Visual Studio 2008 + Boost 1.35:runtime casting not working
The base class MUST be polymorphic - that is have at least one virtual function.
AND the the pointer to the base class - not the derived class should be serialized.
How strict is the requirement that a base class has to be polymorphically connected to the derived class? I have a class that derives from a class template that uses the curiously-recurring template pattern. Such base classes are usually without any kind of virtual stuff, to allow inlining of parent methods and avoid the hit virtual dispatch. //============================================== template < class Derived > class counter_base { public: void count() { ++counter; } int current_count() const { return counter; } protected: counter_base() : counter( 0 ) {} private: int counter; friend class boost::serialization::access; template < class Archive > void serialize( Archive &ar, unsigned const file_version ) { ar & counter; } }; class my_class : private counter_base<my_class> { typedef counter_base<my_class> base_type; typedef my_class self_type; public: explicit my_class( double factor = 1.0 ) : factor( factor ) {} double next() { count(); return factor * current_count(); } private: double factor; friend class boost::serialization::access; template < class Archive > void serialize( Archive &ar, unsigned const file_version ) { ar & ???; // what goes here for base_type (or base_type::counter)? ar & factor; } }; //============================================== -- Daryle Walker Mac, Internet, and Video Game Junkie darylew AT hotmail DOT com