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Re: Portability of preprocessor directives
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From: |
Thomas Dickey |
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Subject: |
Re: Portability of preprocessor directives |
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Date: |
Tue, 25 Feb 2003 15:38:24 -0500 |
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User-agent: |
Mutt/1.3.27i |
On Tue, Feb 25, 2003 at 11:49:17AM -0800, Paul Eggert wrote:
> "Paul D. Smith" <address@hidden> writes:
>
> > What is the word on portability of preprocessor directives?
> >
> > I'm in particular thinking of things like "#if defined()",
> > "#elif !defined()", the && and || operators, etc.
taking it out of context, he did ask about pre-ANSI compilers.
both of these comments below are misleading, since there are known
cases for pre-ANSI compilers which violated the rules.
> The original traditional C preprocessor did not support #elif, but
> compilers without #elif are long dead and are no longer worth worrying
> about.
>
> The original traditional C preprocessor required '#' to be in column
> 1. Typical GNU programs still put '#' in column 1, but I think this
> is now more of a style thing than a requirement. If you're worried
> about older compilers then it might be best to stick with the style
> for a few years more, anyway.
>
--
Thomas E. Dickey <address@hidden>
http://invisible-island.net
ftp://invisible-island.net