Note that the tutorial programs do use BOOST_IS_ABSTRACT so I've always assumed that it functions as advertised. Since the demo doesn't use BOOST_EXPORT, I suspect that that there is some sort of problem related to instantiation of abstract base class code for exported types. I'lll look into it. Robert Ramey "RIVASSEAU Jean Noel" <JN.RIVASSEAU@oberthurcs.com> wrote in message news:87F60F7FA02FF749AFB02BD9FCAA6B04DE1BE3@naserv31.nanterre.oberthurcs.com... I quote the Boost serialization docs: When serializing an object through a pointer to its base class and that base class is abstract (i.e. has at least one virtual function assigned a value of 0), A compile error will be emitted. This is addressable in one over several ways: remove the =0 in the base classes so that the base class is no longer abstract. implement is_abstract for your compiler. (code written according to the C++ standard is included with this library. But it is known to fail on several compilers. If the compiler suports "is_abstract" type trait - use that. Otherwise assume a class is NOT abstract unless BOOST_IS_ABSTRACT has been set for the class. use the macro BOOST_IS_ABSTRACT(my_class) to indicate that the class is an abstract base class. This will cause the compiler to avoid generating code that causes this error. I still do not understand part 2 of this advice, Robert. Could you explain? Jean-Noël Ps: as already mentioned, part 3 does not change anything for me, and I'd like to avoid the solution of part 1 since I do want the base class to be abstract. _______________________________________________ Boost-users mailing list Boost-users@lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users