I'm using the dynamic biset in a project, but when I compile my code in debug with Visual Studio 2008, I get this error: C:\REPOSI~1\Boost\BOOST_~2\boost/dynamic_bitset/dynamic_bitset.hpp(1727) : error C2668: '_wassert' : ambiguous call to overloaded function C:\Program Files\Microsoft Visual Studio 9.0\VC\INCLUDE\assert.h(28): could be 'void _wassert(const wchar_t *,const wchar_t *,unsigned int)' C:\Program Files\Microsoft Visual Studio 9.0\VC\INCLUDE\assert.h(28): or 'void `anonymous-namespace'::_wassert(const wchar_t *,const wchar_t *,unsigned int)' while trying to match the argument list '(const wchar_t [44], const wchar_t [67], int)' The only solution that I found is to comment the line. Do you have a better one? Thank you in advance. Mirko **