Hi, I've tried to build this simple code using vc 7.1 using namespace boost::gregorian; date d(2004, Apr, 5); std::ofstream ofs("date_demo.txt"); boost::archive::text_oarchive oa(ofs); oa << d; but it fails due to a static assertion. The code is taken from the very first lines of boost_serialization_demo.cpp. It seems to compile with boost 1.32, but seems to fail with current boost. Since this demo is not be included in the jamfile (or I was not able to find it), I built it is using visual studio IDE. The compiler command-line options were: /Od /D "WIN32" /D "_DEBUG" /D "_CONSOLE" /D "_MBCS" /Gm /EHsc /RTC1 /MLd /Fo"Debug/" /Fd"Debug/vc70.pdb" /W3 /nologo /c /Wp64 /ZI /TP I also tried to turn on/off the RTTI, but the result did not change. The error I get is d:\PROJECTS\boost\boost\archive\detail\oserializer.hpp(557) : error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' Am I missing something? Thanks, Paolo