Date: Mon, 14 Feb 2000 09:39:55 +0200 (IST) From: Eli Zaretskii X-Sender: eliz AT is To: David Cleaver cc: djgpp AT delorie DOT com Subject: Re: Values in header ?? (urgent) In-Reply-To: <38A6F842.1733F407@ou.edu> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Reply-To: djgpp AT delorie DOT com Errors-To: dj-admin AT delorie DOT com X-Mailing-List: djgpp AT delorie DOT com X-Unsubscribes-To: listserv AT delorie DOT com Precedence: bulk On Sun, 13 Feb 2000, David Cleaver wrote: > I was wondering why you can do this when I was told just a few weeks ago > that I shouldn't use the underscore character in my header declaration. > ie, In your example, I shouldn't use __example_h_ , everyone told me > that it should be changed to example_h_ in order to use good programming > style. Please, I would just like an explanation of why I was told > this. The reason someone could have told you this is that the ANSI C standard says that all macro names which begin with two underscores or one underscore and an uppercase letter are *reserved*. This means that the library implementors are free to use such names without risking to step on user-defined macros. If you use such names, your program might commit all kinds of atrocities, like breaking system headers or otherwise be buggy.