Hi Robert I got this error from error C2039: 'integral_c_tag' : n'est pas membre de 'boost::mpl' Here the beginning of level.hpp I got: ---------------------------------------------------------------------------- ------ #include <boost/mpl/int.hpp> #include <boost/mpl/integral_c.hpp> #include <boost/serialization/level_enum.hpp> #include <boost/serialization/traits.hpp> namespace boost { namespace serialization { // default serialization implementation level template<class T> struct implementation_level { template<class U> struct traits_class_level { typedef BOOST_DEDUCED_TYPENAME U::level type; }; typedef mpl::integral_c_tag tag; // <== problem here // #if BOOST_WORKAROUND(__IBMCPP__, BOOST_TESTED_AT(600)) // typedef ---------------------------------------------------------------------------- --------

From what I check of the latest HEAD release from CVS, it should be integral_c instead of integral_c_tag??

Regards FA