In what module does the following utility macro: #if defined( __GNUC__ ) #define BOOST_PRAGMA_MESSAGE_IMPL_1( x ) _Pragma( #x ) #define BOOST_PRAGMA_MESSAGE( x ) BOOST_PRAGMA_MESSAGE_IMPL_1( message( x ) ) #elif defined( _MSC_VER ) #define BOOST_PRAGMA_MESSAGE_IMPL_2( x, f, ln ) __pragma( message( f "(" #ln "): note: " x ) ) #define BOOST_PRAGMA_MESSAGE_IMPL_1( x, f, ln ) BOOST_PRAGMA_MESSAGE_IMPL_2( x, f, ln ) #define BOOST_PRAGMA_MESSAGE( x ) BOOST_PRAGMA_MESSAGE_IMPL_1( x, __FILE__, __LINE__ ) #else #define BOOST_PRAGMA_MESSAGE( x ) #endif belong? Use: BOOST_PRAGMA_MESSAGE( "something" ) MS output: .\testbed.cpp(10): note: something g++ output: testbed.cpp:10:35: note: #pragma message: something BOOST_PRAGMA_MESSAGE( "something" ) ^