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Re: structs passed by copy

From Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups comp.lang.c
Subject Re: structs passed by copy
Date 2023-02-17 22:21 -0800
Organization None to speak of
Message-ID <87ttzjpk73.fsf@nosuchdomain.example.com> (permalink)
References <76ec6d87-0f5d-4671-b4c8-7023e3da787an@googlegroups.com> <d2231fed-a5b7-40ab-9485-ae39d4061086n@googlegroups.com> <tspokj$3t7aa$2@dont-email.me>

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James Kuyper <jameskuyper@alumni.caltech.edu> writes:
> On 2/17/23 17:10, Maciej Zelma wrote:
>> On Friday, January 20, 2023 at 1:41:16 PM UTC-5, Thiago Adams wrote:
>>
>>> structs arguments passed by copy by default. 
>>
>> Because C uses a "pass-by-value" approach for function arguments, it's
>> design choice afaik.
>
> That answer doesn't quite fit the actual history. As originally
> designed, C did not allow structs to be passed by value, that feature
> was only added later. Originally, only pointers to structs could be passed.

Right -- but those pointers have always been passed by value.

*All* function arguments are passed by value.  You can emulate
pass-by-reference by passing the address of an object (a value of
pointer type).

What changed (some time before K&R1) is that it became possible to pass
struct values as function arguments.  Struct pointers could be passed
before and after that change.

(As for arrays, the language has some syntactic sugar that can make it
look like they're being passed by reference, but again it's all just
pointers being passed by value.)

Of course you know all this.  I'm just providing a slightly different
perspective.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for XCOM Labs
void Void(void) { Void(); } /* The recursive call of the void */

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structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-01-20 10:41 -0800
  Re: structs passed by copy gazelle@shell.xmission.com (Kenny McCormack) - 2023-01-20 19:01 +0000
    Re: structs passed by copy Anton Shepelev <anton.txt@gmail.com> - 2023-01-20 23:01 +0300
      Re: structs passed by copy gazelle@shell.xmission.com (Kenny McCormack) - 2023-01-20 21:28 +0000
        Re: structs passed by copy Kaz Kylheku <864-117-4973@kylheku.com> - 2023-01-21 09:14 +0000
        Re: structs passed by copy Joe Pfeiffer <pfeiffer@cs.nmsu.edu> - 2023-01-21 10:58 -0700
          Re: structs passed by copy gazelle@shell.xmission.com (Kenny McCormack) - 2023-01-21 18:00 +0000
          Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-21 16:14 -0800
            Re: structs passed by copy James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-22 16:00 -0500
              Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-22 13:07 -0800
              Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-22 13:27 -0800
                Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-22 13:51 -0800
                Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-22 13:51 -0800
                Re: structs passed by copy James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-22 17:11 -0500
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-22 16:01 -0800
                Re: structs passed by copy Richard Damon <Richard@Damon-Family.org> - 2023-01-22 21:22 -0500
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-01-23 10:46 +0100
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-23 12:15 -0800
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-01-23 21:47 +0100
                Re: structs passed by copy Michael S <already5chosen@yahoo.com> - 2023-01-23 13:21 -0800
                Re: structs passed by copy Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-01-23 23:49 +0000
                Re: structs passed by copy Michael S <already5chosen@yahoo.com> - 2023-01-24 02:46 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 04:18 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 04:45 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 04:54 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 05:26 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 05:38 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 05:53 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 06:20 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 06:56 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-24 07:17 -0800
                Re: structs passed by copy Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-01-24 12:56 +0000
                Re: structs passed by copy Michael S <already5chosen@yahoo.com> - 2023-01-24 07:29 -0800
                Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-01-23 15:44 -0800
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-23 16:37 -0800
                Re: structs passed by copy James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-23 20:13 -0500
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-23 17:58 -0800
                Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-01-24 07:53 -0800
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-24 11:14 -0800
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-24 12:02 -0800
                Re: structs passed by copy Phil Carmody <pc+usenet@asdf.org> - 2023-01-25 10:18 +0200
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-25 10:53 -0800
                Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-01-29 13:30 -0800
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-29 17:42 -0800
                Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-17 07:19 -0800
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-17 09:35 -0800
                Re: structs passed by copy John Forkosh <forkosh@panix.com> - 2023-01-30 04:24 +0000
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-29 21:10 -0800
                Re: structs passed by copy Michael S <already5chosen@yahoo.com> - 2023-01-30 13:55 -0800
                Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-17 05:57 -0800
      Re: structs passed by copy James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-01-21 05:00 -0500
        Re: structs passed by copy Anton Shepelev <anton.txt@gmail.com> - 2023-01-21 23:00 +0300
          Re: structs passed by copy Richard Damon <Richard@Damon-Family.org> - 2023-01-21 17:10 -0500
    Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-01-20 18:12 -0800
    Re: structs passed by copy antispam@math.uni.wroc.pl - 2023-01-21 02:28 +0000
  Re: structs passed by copy Blue-Maned_Hawk <bluemanedhawk@gmail.com> - 2023-01-20 14:09 -0500
    Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-20 11:26 -0800
  Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-20 11:22 -0800
  Re: structs passed by copy Bart <bc@freeuk.com> - 2023-01-20 20:16 +0000
    Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-01-20 19:16 -0800
      Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-01-20 21:08 -0800
      Re: structs passed by copy Bart <bc@freeuk.com> - 2023-01-21 13:30 +0000
        Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 10:27 -0800
  Re: structs passed by copy Richard Damon <Richard@Damon-Family.org> - 2023-01-20 21:35 -0500
  Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-20 19:01 -0800
    Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-21 17:01 -0800
  Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-01-21 14:59 +0100
  Re: structs passed by copy Opus <ifonly@youknew.org> - 2023-01-21 19:59 +0100
  Re: structs passed by copy Michael S <already5chosen@yahoo.com> - 2023-01-21 16:55 -0800
    Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-01-22 02:32 -0800
      Re: structs passed by copy Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-01-22 15:54 +0000
        Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 09:17 -0800
          Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 09:56 -0800
            Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 10:19 -0800
              Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 11:01 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 11:08 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 11:17 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-01-22 13:27 -0800
        Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-22 13:04 -0800
          Re: structs passed by copy Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-01-22 21:43 +0000
            Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-22 14:10 -0800
              Re: structs passed by copy Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-01-22 22:29 +0000
                Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-01-22 14:39 -0800
                Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-01-22 19:06 -0800
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-01-23 10:54 +0100
        Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-01-22 19:00 -0800
          Re: structs passed by copy Ben Bacarisse <ben.usenet@bsb.me.uk> - 2023-01-23 12:14 +0000
  Re: structs passed by copy Jorgen Grahn <grahn+nntp@snipabacken.se> - 2023-02-11 19:35 +0000
    Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-11 15:08 -0800
      Re: structs passed by copy Öö Tiib <ootiib@hot.ee> - 2023-02-11 15:56 -0800
        Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-11 16:32 -0800
          Re: structs passed by copy James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-02-12 01:23 -0500
            Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-02-12 11:24 +0100
              Re: structs passed by copy Vir Campestris <vir.campestris@invalid.invalid> - 2023-02-12 22:11 +0000
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-02-13 10:25 +0100
                Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-02-13 06:41 -0800
                Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-02-13 06:50 -0800
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-02-13 17:22 +0100
                Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-02-13 10:47 -0800
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-02-13 21:50 +0100
                Re: structs passed by copy bart c <bart4858@gmail.com> - 2023-02-15 17:14 -0800
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-02-16 10:53 +0100
                Re: structs passed by copy scott@slp53.sl.home (Scott Lurndal) - 2023-02-16 15:22 +0000
            Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-12 11:04 -0800
          Re: structs passed by copy Öö Tiib <ootiib@hot.ee> - 2023-02-12 12:41 -0800
          Re: structs passed by copy Andrey Tarasevich <andreytarasevich@hotmail.com> - 2023-02-16 22:49 -0800
      Re: structs passed by copy "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2023-02-11 17:49 -0800
      Grammar nitpick (Was: structs passed by copy) gazelle@shell.xmission.com (Kenny McCormack) - 2023-02-12 06:30 +0000
      Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-03-06 09:32 -0800
        Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-03-06 09:58 -0800
          Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-03-06 11:30 -0800
            Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-03-06 12:59 -0800
    Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-15 01:52 -0800
      Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-02-16 05:20 -0800
        Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-02-16 16:49 +0100
        Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-02-26 08:12 -0800
          Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-02-28 05:38 -0800
            Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-28 14:18 -0800
              Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-03-01 05:02 -0800
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-03-01 10:23 -0800
                Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-03-01 10:42 -0800
                Re: structs passed by copy bart c <bart4858@gmail.com> - 2023-03-01 15:13 -0800
                Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-03-02 04:17 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-03-05 04:17 -0800
                Re: structs passed by copy fir <profesor.fir@gmail.com> - 2023-03-05 04:55 -0800
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-03-02 10:48 +0100
                Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-03-02 04:07 -0800
                Re: structs passed by copy David Brown <david.brown@hesbynett.no> - 2023-03-02 15:08 +0100
                Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-03-02 09:22 -0800
              Re: structs passed by copy gazelle@shell.xmission.com (Kenny McCormack) - 2023-03-01 13:34 +0000
                Re: structs passed by copy Richard Damon <Richard@Damon-Family.org> - 2023-03-01 21:42 -0500
            Re: structs passed by copy Tim Rentsch <tr.17687@z991.linuxsc.com> - 2023-03-06 09:36 -0800
  Re: structs passed by copy Maciej Zelma <maciej.projectmanager@gmail.com> - 2023-02-17 14:10 -0800
    Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-17 15:45 -0800
      Re: structs passed by copy scott@slp53.sl.home (Scott Lurndal) - 2023-02-18 00:12 +0000
        Re: structs passed by copy bart c <bart4858@gmail.com> - 2023-02-18 02:33 -0800
    Re: structs passed by copy James Kuyper <jameskuyper@alumni.caltech.edu> - 2023-02-18 00:44 -0500
      Re: structs passed by copy Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2023-02-17 22:21 -0800
  Re: structs passed by copy Bonita Montero <Bonita.Montero@gmail.com> - 2023-03-01 18:00 +0100
    Re: structs passed by copy Thiago Adams <thiago.adams@gmail.com> - 2023-03-01 09:18 -0800
      Re: structs passed by copy Bonita Montero <Bonita.Montero@gmail.com> - 2023-03-05 14:05 +0100

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