Hello, I have some trouble using boost::extension and boost::optional together in a project (MSVC 7.1). The compiler complains that boost::get is not an element of extensions::shared_library. Without the optional.hpp header everything works fine. It seems the for some reason the macro BOOST_EXTENSION_SHARED_LIBRARY_GET_FUNCTION isn't valid when shared_library.get<>() is called but I can't find out why. A small code snippet that reproduces the error file: test_extension_and_optional.cpp #include <boost/optional/optional.hpp> // included for some reason #include <boost/extension/shared_library.hpp> #include <boost/extension/convenience.hpp> // load_single_library void loadExtension () { boost::extensions::factory_map fm; // we don't need the following line to produce the compiler error //boost::extensions::load_single_library(fm, ".", "external_function_name"); } error: error C2039: 'boost::get': Ist kein Element von 'boost::extensions::shared_library' Thanks in advance. David -- David Matz ---------------------------- Software Developer Spatial View GmbH mail: david.matz@spatialview.com phone: +49 351 - 4 50 33 44 registration court: Amtsgericht Dresden, HRB 21104 managing directors: Wolfgang Opel, Jens Wiegrebe