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From: philip@pescadero.Stanford.EDU (Philip Machanick)
Newsgroups: comp.lang.c++
Subject: Re: #defines....
Message-ID: <1990Jul2.164355.15327@Neon.Stanford.EDU>
Date: 2 Jul 90 16:43:55 GMT
References: <37786@genrad.UUCP>
Sender: news@Neon.Stanford.EDU (USENET News System)
Reply-To: philip@pescadero.stanford.edu
Organization: Computer Science Department, Stanford University
Lines: 20

In article <37786@genrad.UUCP>, slp@genrad.uucp (Steven L. Peters) writes:
> Just out of curiousity...
> 
> With the C++ const, enum, and inline declarations, is it ever
> necessary to use #define in a C++ program?  Stroustrup emphatically
> says in _The C++ Programming Language_ not to use them if you don't
> have to.  I'm wondering if you ever have to.  I can't think of a
> single time where you would be forced to use a #define over const or
> inline...
> 
Just a small example... errno, which contains an error number from
the most recent error (used in a number of common libraries) is defined
as an integer _expression_. It can for example be implemented as a
function call. Could the same effect be achieved with any of the new
constructs? I think not, because function calls and variable references
are syntactically different in C/C++ (unlike some other languages, where
a parameterless function looks like a variable reference).

Philip Machanick
philip@pescadero.stanford.edu