----- Original Message ----- From: "Vesa Karvonen" <[EMAIL PROTECTED]> To: <[EMAIL PROTECTED]> Sent: Sunday, January 05, 2003 3:45 PM Subject: Re: [boost] Boost.Preprocessor: Alternatives to defined(x)
> David Abrahams: > > > Paul Mensonides: > > > > The semantic change is that 'x' must not be a function-like macro. > ^^^ > [...] > >How can you use a macro which only tells you if a function-like macro > >is defined to tell you if an object-like macro is defined? > > >If we could do that, couldn't you implement your original intended > >semantics? > > Well, yes. It could be used for testing whether an object-like config macro > has been defined. > > Actually, since it is not currently possible (portable) to pass around empty > parameters, it really shouldn't make much difference that function-like > macros may not be tested. That is why I said the semantic change was minor. The major difference is that it disallows passing any function-like macro that takes any arguments into the IS_EMPTY macro. It can still be used to test object-like macros. Anyway, I might still be able to make the original ideal work with VC and Metrowerks. (You wouldn't believe how sick I am of those two compilers!) Give me some time.... Paul Mensonides _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
