I've noticed discussions about this a couple of years ago. For assert-style macros that include multiple statements, a common idiom is to enclose the statements in a do{...}while(0) dummy loop. This makes the macro behave like a single statement. A problem with some compilers (notably VC7.x) is that this triggers a warning (C4127: conditional expression is constant). The workaround adopted by boost is to automatically disable this warning -- which however can be legitimate and useful in user code. I think I have found a better 'always-false' condition which does not trigger a warning, and works at least in VC7.1: do{ }while(__LINE__==-1) Do you see a problem with this approach? Could this approach be used to stop disabling warning 4127 when boost is compiled? Do other compilers have similar warnings and workarounds? Should a boost macro that expands to a warning-free always-false (or always-true) compile-time constant be considered? This would also allow statements such as BOOST_ASSERT(BOOST_FALSE), while(BOOST_TRUE), or do{...}while(BOOST_FALSE) to compile without warning... Regards, Ivan -- http://ivan.vecerina.com/contact/?subject=NG_POST <- email contact form