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| Message-ID | <4DCD65A2.4FD0@mindspring.com> (permalink) |
|---|---|
| Date | 2011-05-13 13:08 -0400 |
| From | pete <pfiland@mindspring.com> |
| Organization | PF |
| Newsgroups | comp.lang.c |
| Subject | Re: macro conventions |
| References | <4dcd62ab$0$23874$bbae4d71@news.suddenlink.net> |
Bill Cunningham wrote:
>
> In defining macros it is of course proper style
> to use all caps for
> example:
>
> #define AVG 14
>
> There are other conventions too. In trying to learn what is the
> diference in having one underscore and two underscores
> in front of or behine a macro? For example:
>
> #define __FILE__
>
> Two underscores if front of and behind the define. And here:
>
> #define _GNU_SOURCE
>
> One underscore in front and no underscores at the end.
> I hope this is clear.
> I want to be sure of these things.
The more important thing,
is to realise that your C implementation uses
some macro conventions which you are not supposed to use.
Macros with leading underscores are an example of that.
ISO/IEC 9899:1999 (E)
7.1.3 Reserved identifiers
1 Each header declares or defines all identifiers listed
in its associated subclause,
and optionally declares or defines identifiers listed
in its associated future library directions subclause
and identifiers which are always reserved either
for any use or for use as file scope identifiers.
— All identifiers that begin with an underscore
and either an uppercase letter or another underscore
are always reserved for any use.
--
pete
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macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-13 12:56 -0400
Re: macro conventions pete <pfiland@mindspring.com> - 2011-05-13 13:08 -0400
Re: macro conventions Shao Miller <sha0.miller@gmail.com> - 2011-05-13 13:14 -0400
Re: macro conventions Keith Thompson <kst-u@mib.org> - 2011-05-13 11:41 -0700
Re: macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-14 23:08 -0400
Re: macro conventions ralph <nt_consulting64@yahoo.net> - 2011-05-13 13:15 -0500
Re: macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-14 23:11 -0400
Re: macro conventions "Bill Cunningham" <nospam@nspam.invalid> - 2011-05-15 04:00 -0400
Re: macro conventions Angel <angel+news@spamcop.net> - 2011-05-15 11:15 +0000
Re: macro conventions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-05-16 04:36 +0300
Re: macro conventions Ike Naar <ike@sverige.freeshell.org> - 2011-05-16 09:56 +0000
Re: macro conventions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-05-16 19:00 +0300
Re: macro conventions Seebs <usenet-nospam@seebs.net> - 2011-05-16 19:10 +0000
Re: macro conventions Phil Carmody <thefatphil_demunged@yahoo.co.uk> - 2011-05-22 21:27 +0300
Re: macro conventions Keith Thompson <kst-u@mib.org> - 2011-05-15 06:50 -0700
Re: macro conventions Malcolm McLean <malcolm.mclean5@btinternet.com> - 2011-05-15 08:29 -0700
Re: macro conventions Ian Collins <ian-news@hotmail.com> - 2011-05-16 07:40 +1200
Re: macro conventions "osmium" <r124c4u102@comcast.net> - 2011-05-15 14:52 -0500
Re: macro conventions ralph <nt_consulting64@yahoo.net> - 2011-05-16 02:22 -0500
Re: macro conventions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-16 14:18 +0100
Re: macro conventions David Resnick <lndresnick@gmail.com> - 2011-05-16 08:03 -0700
Re: macro conventions Ben Bacarisse <ben.usenet@bsb.me.uk> - 2011-05-16 17:32 +0100
Re: macro conventions Keith Thompson <kst-u@mib.org> - 2011-05-16 08:43 -0700
Re: macro conventions Michael Press <rubrum@pacbell.net> - 2011-05-16 14:47 -0700
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