Hello, I am trying to learn the Boost Serialization Library. Although I like the fundamental principles of the library, using the library so far has proven a nightmare for my project. To be more precise: I need to serialize objects via pointers to base class. And I need to do it without RTTI. While using extended_type_info_no_rtti for my classes I always get an "unregistered_class" exception at run time. But I have done the following: in all my classes, in the implementation unit (.cpp) I have included explicitely the headers needed for the archives I use: #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> Then I have something like that in each class: #include <boost/serialization/base_object.hpp> #include <boost/serialization/type_info_implementation.hpp> #include <boost/serialization/extended_type_info_no_rtti.hpp> #include <boost/serialization/export.hpp> namespace boost { namespace serialization { template<class Archive> void serialize(Archive & ar, PrimitiveMemberVariableSpecification & m, const unsigned int version) { ar & boost::serialization::base_object<MemberVariableSpecification>(m); ar & m.unused_primitive_type; } } // namespace serialization } // namespace boost BOOST_CLASS_TYPE_INFO( PrimitiveMemberVariableSpecification, extended_type_info_no_rtti<PrimitiveMemberVariableSpecification> ) BOOST_CLASS_EXPORT(PrimitiveMemberVariableSpecification) (Here the name of the class is PrimitiveMemberVariableSpecification. I also want to report a bug in the documentation: the doc says that you should write: BOOST_CLASS_TYPE_INFO( ClassName, extended_type_info_no_rtti<BaseClassName> ) Although the example test_no_rtti.cpp uses the following syntax: BOOST_CLASS_TYPE_INFO( ClassName, extended_type_info_no_rtti<ClassName> ) I think that the example is right, not the documentation. ) Normally the BOOST_CLASS_EXPORT should *register* all my classes. Why doesn't it work? I have of course also written a correct get_key() virtual function for all my classes. If I just change extended_type_info_no_rtti to extended_type_info_typeid, everything works fine, but I do want extended_type_info_no_rtti. Also, keeping everything in the headers files seems to be a nightmare, although that is what Robert Ramsey recommends. I get tons of multiple definitions errors at link time if I do that (something like: multiple definition of `boost::archive::detail::guid_initializer<MemberVariableSpecification>::instance' with gcc - MinGW 3.4.2) I have looked at the documentation for two days, read absolutely everything and still do not understand. Maybe I should look at the code ??? Thank you Jean-Noël