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

From	Dr Nick <nospam-4@temporary-address.org.uk>
Newsgroups	comp.lang.c
Subject	Re: Making C more beautiful by not using macros with arguments
References	<032b4cc1-a813-4caa-a810-569e1ea3b0ab@googlegroups.com> <87pp5jjd89.fsf@kst-u.example.com> <04b63e89-57a9-4164-9de2-a4715dc5a8ef@googlegroups.com> <0Qqax.50189$617.4901@fx27.iad> <556C8A6D.5070305@verizon.net>
Date	2015-06-01 19:20 +0100
Message-ID	<87bngze1eu.fsf@temporary-address.org.uk> (permalink)

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James Kuyper <jameskuyper@verizon.net> writes:

> On 05/30/2015 06:28 PM, Lew Pitcher wrote:
>> On Saturday May 30 2015 10:46, in comp.lang.c, "David Kleinecke"
>> <dkleinecke@gmail.com> wrote:
>> 
>>> On Friday, May 29, 2015 at 2:17:12 PM UTC-7, Keith Thompson wrote:
>>>>
>>>> I can write:
>>>>
>>>>     #define MAX(x, y) ((x) > (y) ? (x) : (y))
>>>>
>>>> How would you suggest writing that as a parameterless macro?
>>>  
>>> Wouldn't
>>>     #define MAX_1 x
>>>     #define MAX_2 y
>>>     #define MAX ((MAX_1) > (MAX_2) ? (MAX_1) : (MAX_2))
>>> do the same thing?
>
> I've been looking at the responses to this suggestion, and no one seems
> to have pointed out what I think is the biggest problem with this
> approach - code that uses MAX() more than once, with different arguments.
>
> Here's some real-world code (I'm responsible for it, though I didn't
> write it - but I don't see anything wrong with it):
>
>>      max_SD_packets =
>>                  MAX((scan_meta->frame_count_array[MD_SD_FRAMES_IN_SCAN] * 2),
>>                      PH_REALISTIC_NUM_SD_PACKETS);
>> 
>>      max_SRCA_packets =
>>                  MAX((scan_meta->frame_count_array[MD_SRCA_FRAMES_IN_SCAN] * 2), 
>>                      PH_REALISTIC_NUM_SRCA_PACKETS);
>> 
>>      max_BB_packets =
>>                  MAX((scan_meta->frame_count_array[MD_BB_FRAMES_IN_SCAN] * 2),
>>                      PH_REALISTIC_NUM_BB_PACKETS);
>> 
>>      max_SV_packets =
>>                  MAX((scan_meta->frame_count_array[MD_SV_FRAMES_IN_SCAN] * 2),
>>                      PH_REALISTIC_NUM_SV_PACKETS);
>
> Is David Kleinecke seriously suggesting that this code would be improved
> by re-writing it as follows:
>
> #undef MAX_1
> #undef MAX_2
> #define MAX_1 (scan_meta->frame_count_array[MD_SD_FRAMES_IN_SCAN] * 2)
> #define MAX_2 PH_REALISTIC_NUM_SD_PACKETS
> 	max_SD_packets = MAX;
>
> #undef MAX_1
> #undef MAX_2
> #define MAX_1 (scan_meta->frame_count_array[MD_SRCA_FRAMES_IN_SCAN] * 2)
> #define MAX_2 PH_REALISTIC_NUM_SRCA_PACKETS
> 	max_BB_packets = MAX;
>
> // etc.
>
> !?

That's exactly what I think he's suggesting.  I still can't work out
why.

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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