Re: Concerning the necessity of include guards

From	David Brown <david.brown@hesbynett.no>
Newsgroups	comp.lang.c
Subject	Re: Concerning the necessity of include guards
Date	2020-02-25 13:03 +0100
Organization	A noiseless patient Spider
Message-ID	<r332f7$fe6$1@dont-email.me> (permalink)
References	<20200224220814.34562e1774fd4d2c65f171a0@gmail.com> <87k14b4vv1.fsf@bsb.me.uk> <r31fnc$t6b$1@dont-email.me> <20200225141351.8b50facbd1498ce2848f12a1@g{oogle}mail.com>

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On 25/02/2020 12:13, Anton Shepelev wrote:
> David Brown:
> 
>> It should not make any difference to any code using this
>> header.  But as you say, many people would feel it looks
>> more like a complete and ready-to-user header file if the
>> guards are included.  Certainly it will be useful if other
>> features (types, macros, etc.) are added at a later date.
>>
>> Include guards also make the compilation more efficient
>> (many compilers have very fast skipping of duplicate
>> headers with include guards).  I can't imagine the effect
>> will be measurable if you just have a few function
>> declarations, but it can be a reason people have for such
>> habits.
>>
>> To the OP -- why did you choose not to have a guard?
> 
> To keep header as lean and clean as possible.  These guards
> are mechanical boilerplate that contaminate the
> declarations. 

I can appreciate that.  But I think it is easier to view the guard as
simply a standard part of a C header.

A lot of headers need more than function declarations.  You have types
to declare, and maybe macros.  You have include files to include - I
almost invariably need <stdbool.h> and <stdint.h> as a minimum.  (These
have their own include guards, so don't require guards in a header that
uses them.)  To me, a header without include guards would stand out as
being odd, as most need them.

> Nevertheless, I have now been reconvinced and
> will add the guard to my header.  Thanks to everybody for
> your replies.
>

Thread

Concerning the necessity of include guards Anton Shepelev <anton.txt@gmail.com> - 2020-02-24 22:08 +0300
  Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-24 20:28 +0100
  Re: Concerning the necessity of include guards Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-02-24 19:40 +0000
    Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-24 22:37 +0100
      Re: Concerning the necessity of include guards Anton Shepelev <anton.txt@g{oogle}mail.com> - 2020-02-25 14:13 +0300
        Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 13:03 +0100
          Re: Concerning the necessity of include guards Anton Shepelev <anton.txt@gmail.com> - 2020-02-29 01:14 +0300
            Re: Concerning the necessity of include guards Bart <bc@freeuk.com> - 2020-02-28 22:36 +0000
              Re: Concerning the necessity of include guards Anton Shepelev <anton.txt@gmail.com> - 2020-02-29 13:28 +0300
            Re: Concerning the necessity of include guards Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-02-29 00:08 +0000
            Re: Concerning the necessity of include guards Richard Damon <Richard@Damon-Family.org> - 2020-02-29 07:05 -0500
            Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-03-01 15:01 +0100
  Re: Concerning the necessity of include guards Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-02-24 14:52 -0500
    Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-24 21:19 +0100
      Re: Concerning the necessity of include guards Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-02-24 15:48 -0500
        Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-24 21:53 +0100
          Re: Concerning the necessity of include guards Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-02-24 17:26 -0500
            Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 00:08 +0100
              Re: Concerning the necessity of include guards Thiago Adams <thiago.adams@gmail.com> - 2020-02-24 15:24 -0800
                Re: Concerning the necessity of include guards Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-02-24 22:20 -0800
                Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 09:52 +0100
            Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-25 08:12 +0100
              Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 09:55 +0100
                Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-25 10:35 +0100
                Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 13:13 +0100
                Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-25 13:50 +0100
                Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 18:33 +0100
                Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-25 18:38 +0100
                Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 18:42 +0100
                Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-25 18:46 +0100
                Re: Concerning the necessity of include guards Bart <bc@freeuk.com> - 2020-02-25 19:35 +0000
                Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 21:18 +0100
                Re: Concerning the necessity of include guards Bonita Montero <Bonita.Montero@gmail.com> - 2020-02-26 06:40 +0100
                Re: Concerning the necessity of include guards James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-25 12:12 -0800
                Re: Concerning the necessity of include guards James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-02-25 11:55 -0800
                Re: Concerning the necessity of include guards David Brown <david.brown@hesbynett.no> - 2020-02-25 21:37 +0100
                Re: Concerning the necessity of include guards scott@slp53.sl.home (Scott Lurndal) - 2020-02-26 02:39 +0000
                Re: Concerning the necessity of include guards Real Troll <real.troll@trolls.com> - 2020-02-25 23:10 -0400
                Re: Concerning the necessity of include guards chad <cdalten@gmail.com> - 2020-02-27 05:39 -0800
  Re: Concerning the necessity of include guards Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-02-24 22:23 +0000
  Re: Concerning the necessity of include guards Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-02-24 21:17 -0800
    Re: Concerning the necessity of include guards Guillaume <message@bottle.org> - 2020-02-25 13:03 +0100

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