I've run into a conflict between use of the polymorphic archives and the BOOST_CLASS_EXPORT() macro. It doesn't seem possible to use both without getting a link error. The following code illustrates the problem (yes, I know this code doesn't do anything worth doing, but it's the simplest code that demonstrates the problem): ---------------------- # include <sstream> # include <boost/serialization/export.hpp> # include <boost/archive/polymorphic_binary_oarchive.hpp> class A { public: template<class Archive> void serialize(Archive & ar, const unsigned version) { } }; BOOST_CLASS_EXPORT(A); int main() { A a; std::ostringstream os; boost::archive::polymorphic_binary_oarchive oa(os); oa & a; } ----------------------- This code compiles OK, but a link error is generated. I've put the full link error at the bottom of this post; the gist is an undefined reference to: boost::archive::detail::archive_serializer_map<boost::archive::detail::p olymorphic_oarchive_route<boost::archive::binary_oarchive_impl<boost::ar chive::binary_oarchive, char, std::char_traits<char> > >

::erase(boost::archive::detail::basic_serializer const*)

::insert(boost::archive::detail::basic_serializer const*)' /tmp/ccQvudrk.o: In function `boost::archive::detail::pointer_oserializer<boost::archive::detail::pol ymorphic_oarchive_route<boost::archive::binary_oarchive_impl<boost::arch ive::binary_oarchive, char, std::char_traits<char> > >, A>::~pointer_oserializer()': test_boost_ser_main.cpp:(.text._ZN5boost7archive6detail19pointer_oserial izerINS1_26polymorphic_oarchive_routeINS0_20binary_oarchive_implINS0_15b inary_oarchiveEcSt11char_traitsIcEEEEE1AED2Ev[_ZN5boost7archive6detail19

I can make the error go away by either: 1) Commenting out the BOOST_CLASS_EXPORT 2) Changing the type of the oarchive from polymorphic_binary_oarchive to binary_oarchive. It really looks like there's something missing from the serialization library related to the polymorphic oarchive. Thanks in advance for any help. Tim Wilson Full link error: ---------------- /tmp/ccQvudrk.o: In function `boost::archive::detail::pointer_oserializer<boost::archive::detail::pol ymorphic_oarchive_route<boost::archive::binary_oarchive_impl<boost::arch ive::binary_oarchive, char, std::char_traits<char> > >, A>::pointer_oserializer()': test_boost_ser_main.cpp:(.text._ZN5boost7archive6detail19pointer_oserial izerINS1_26polymorphic_oarchive_routeINS0_20binary_oarchive_implINS0_15b inary_oarchiveEcSt11char_traitsIcEEEEE1AEC2Ev[_ZN5boost7archive6detail19 pointer_oserializerINS1_26polymorphic_oarchive_routeINS0_20binary_oarchi ve_implINS0_15binary_oarchiveEcSt11char_traitsIcEEEEE1AEC5Ev]+0x4f): undefined reference to `boost::archive::detail::archive_serializer_map<boost::archive::detail:: polymorphic_oarchive_route<boost::archive::binary_oarchive_impl<boost::a rchive::binary_oarchive, char, std::char_traits<char> > > pointer_oserializerINS1_26polymorphic_oarchive_routeINS0_20binary_oarchi ve_implINS0_15binary_oarchiveEcSt11char_traitsIcEEEEE1AED5Ev]+0x24): undefined reference to `boost::archive::detail::archive_serializer_map<boost::archive::detail:: polymorphic_oarchive_route<boost::archive::binary_oarchive_impl<boost::a rchive::binary_oarchive, char, std::char_traits<char> > >

::erase(boost::archive::detail::basic_serializer const*)'

collect2: ld returned 1 exit status