Re: Making C more beautiful by not using macros with arguments

From	Bartc <bc@freeuk.com>
Newsgroups	comp.lang.c
Subject	Re: Making C more beautiful by not using macros with arguments
Date	2015-05-31 23:16 +0100
Organization	A noiseless patient Spider
Message-ID	<mkg164$vb9$1@dont-email.me> (permalink)
References	(5 earlier) <87a8wlk5o3.fsf@bsb.me.uk> <mkejo1$k6c$1@dont-email.me> <87zj4lhxsc.fsf@bsb.me.uk> <ce45f467-6f93-415e-b23f-abd26728bf7e@googlegroups.com> <874mmsh71s.fsf@bsb.me.uk>

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On 31/05/2015 20:37, Ben Bacarisse wrote:
> David Kleinecke <dkleinecke@gmail.com> writes:
> <snip>
>
>> I'm trying to answer your quetsions - hit me again with any I have
>> left unanswered.
>
> You said of the # and ## operators that this aspect of the pre-processor
> is useful but does not require require macros with arguments.  I asked
> two questions:
>
> (1) Can you give an example of a parameter-less macro that uses #?
>
> (2) I posted a use of ## recently:
>
>    #define B(a, b)   BX(PAT_ ## a, PAT_ ## b)
>    #define BX(a, b)  BXX(a, b)
>    #define BXX(a, b) 0x ## a ## b,
>
>    const unsigned image[] = {
>    B(X___,___X)
>    ...etc...
>    };
>
>    How do you do this without arguments?

I tried to do this without arguments (with the entire image definition 
in a macro). But ## doesn't work how I expect it; if A and B are macros, 
then:

  A ## B

will join A and B before expanding them. I need them expanded then 
joined. So the language is indirectly forcing you to use macro arguments 
(as it seems that some extra magic can be done with them).

(Not that this solves all the problems; it would have taken me ages to 
come up with your B, BX and BXX macros, or more likely would never have 
done so. It's still not exactly intuitive.)

-- 
Bartc

Thread

Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-29 10:36 -0700
  Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-29 19:04 +0100
    Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-30 07:30 -0700
      Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-30 15:51 +0100
  Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-29 19:26 +0100
    Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-30 07:38 -0700
      Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-30 21:44 +0100
        Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-30 23:58 +0100
          Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 00:27 +0100
            Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-31 10:21 +0100
              Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 11:00 +0100
                Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-31 09:45 -0700
                Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-31 18:20 +0100
                Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-31 13:04 -0700
                Re: Making C more beautiful by not using macros with arguments Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-05-31 16:11 -0400
                Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-31 21:48 +0100
                Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-31 14:22 -0700
                Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-06-01 11:33 -0700
                Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 20:37 +0100
                Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-31 14:18 -0700
                Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 22:44 +0100
                Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-31 23:16 +0100
                Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-06-01 11:58 -0700
                Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-02 01:14 +0100
                Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-06-02 10:31 +0100
                Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-02 11:06 +0100
                Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-06-02 11:39 +0100
                Re: Making C more beautiful by not using macros with arguments "Rick C. Hodgin" <rick.c.hodgin@gmail.com> - 2015-06-02 04:02 -0700
                Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-02 12:24 +0100
                Re: Making C more beautiful by not using macros with arguments Noob <root@127.0.0.1> - 2015-06-02 15:41 +0200
                Re: Making C more beautiful by not using macros with arguments Richard Heathfield <rjh@cpax.org.uk> - 2015-06-02 15:00 +0100
                Re: Trolls/Cranks/Kooks Noob <root@127.0.0.1> - 2015-06-02 16:41 +0200
                Re: Trolls/Cranks/Kooks Richard Heathfield <rjh@cpax.org.uk> - 2015-06-02 15:56 +0100
                Re: Trolls/Cranks/Kooks Noob <root@127.0.0.1> - 2015-06-02 17:09 +0200
                Re: Trolls/Cranks/Kooks Richard Heathfield <rjh@cpax.org.uk> - 2015-06-02 16:17 +0100
                Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-02 15:58 +0100
                Re: Making C more beautiful by not using macros with arguments Dr Nick <nospam-4@temporary-address.org.uk> - 2015-06-02 19:32 +0100
                Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-06-02 11:00 -0700
                Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-02 20:13 +0100
      Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-30 15:17 -0700
        Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-31 09:12 -0700
          Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-31 13:29 -0700
      Re: Making C more beautiful by not using macros with arguments David Brown <david.brown@hesbynett.no> - 2015-05-31 17:28 +0200
  Re: Making C more beautiful by not using macros with arguments Morris Dovey <mrdovey@iedu.com> - 2015-05-29 13:35 -0500
  Re: Making C more beautiful by not using macros with arguments "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-05-29 13:19 -0700
    Re: Making C more beautiful by not using macros with arguments "Chris M. Thomasson" <nospam@nospam.nospam> - 2015-05-29 13:25 -0700
  Re: Making C more beautiful by not using macros with arguments Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2015-05-29 14:23 -0600
  Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-29 14:16 -0700
    Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-30 07:46 -0700
      Re: Making C more beautiful by not using macros with arguments Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-05-30 18:28 -0400
        Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-31 09:27 -0700
          Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-31 17:59 +0100
            Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-06-01 11:24 -0700
              Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-06-01 12:15 -0700
                Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-06-01 12:21 -0700
                Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-06-01 12:53 -0700
          Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-31 13:36 -0700
          Re: Making C more beautiful by not using macros with arguments David Brown <david.brown@hesbynett.no> - 2015-05-31 23:26 +0200
            Re: Making C more beautiful by not using macros with arguments Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-05-31 23:09 +0100
            Re: Making C more beautiful by not using macros with arguments luser droog <luser.droog@gmail.com> - 2015-05-31 15:51 -0700
              Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-06-01 12:08 -0700
        Re: Making C more beautiful by not using macros with arguments James Kuyper <jameskuyper@verizon.net> - 2015-06-01 12:38 -0400
          Re: Making C more beautiful by not using macros with arguments Dr Nick <nospam-4@temporary-address.org.uk> - 2015-06-01 19:20 +0100
          Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-06-01 12:18 -0700
      Re: Making C more beautiful by not using macros with arguments Keith Thompson <kst-u@mib.org> - 2015-05-30 15:43 -0700
        Re: Making C more beautiful by not using macros with arguments David Kleinecke <dkleinecke@gmail.com> - 2015-05-31 09:32 -0700
  Re: Making C more beautiful by not using macros with arguments Les Cargill <lcargill99@comcast.com> - 2015-05-29 22:07 -0500
  Making C more beautiful by not using macros with arguments rick.c.hodgin@gmail.com - 2015-05-30 09:22 -0700
    Re: Making C more beautiful by not using macros with arguments Morris Dovey <mrdovey@iedu.com> - 2015-05-30 14:22 -0500
      Re: Making C more beautiful by not using macros with arguments Bartc <bc@freeuk.com> - 2015-05-30 21:29 +0100
        Re: Making C more beautiful by not using macros with arguments Morris Dovey <mrdovey@iedu.com> - 2015-05-30 22:15 -0500
          Re: Making C more beautiful by not using macros with arguments Morris Dovey <mrdovey@iedu.com> - 2015-06-08 20:16 -0500
  Re: Making C more beautiful by not using macros with arguments David Brown <david.brown@hesbynett.no> - 2015-05-31 17:32 +0200
  Re: Making C more beautiful by not using macros with arguments Richard Heathfield <rjh@cpax.org.uk> - 2015-06-01 22:51 +0100

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