Re: What is your opinion about unsigned int u = -2 ?

From	Ben Bacarisse <ben@bsb.me.uk>
Newsgroups	comp.lang.c
Subject	Re: What is your opinion about unsigned int u = -2 ?
Date	2024-08-02 16:17 +0100
Organization	A noiseless patient Spider
Message-ID	<87r0b7c5ti.fsf@bsb.me.uk> (permalink)
References	(1 earlier) <pan$d2c8a$8c54ac9f$29a202e0$12c6ce86@invalid.invalid> <87bk2cecan.fsf@bsb.me.uk> <v8inds$2qpqh$1@dont-email.me> <v8iqnr$7l3c$1@news.xmission.com> <v8irje$2rolg$1@dont-email.me>

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Bart <bc@freeuk.com> writes:

> On 02/08/2024 15:33, Kenny McCormack wrote:
>> In article <v8inds$2qpqh$1@dont-email.me>,
>> Thiago Adams  <thiago.adams@gmail.com> wrote:
>> ...
>>> So it seams that anything is ok for unsigned but not for signed.
>>> Maybe because all computer gave same answer for unsigned but this is not
>>> true for signed?
>> I think it is because it wants to (still) support representations other
>> than 2s complement.  I think POSIX requires 2s complement, and I expect the
>> C standard to (eventually) follow suit.
>> 
>
> C23 assumes 2s complement. However overflow on signed integers will still
> be considered UB: too many compilers depend on it.
>
> But even if well-defined (eg. that UB was removed so that overflow just
> wraps as it does with unsigned), some here, whose initials may or may not
> be DB, consider such overflow Wrong and a bug in a program.
>
> However they don't consider overflow of unsigned values wrong at all,
> simply because C allows that behaviour.
>
> But I don't get it. If my calculation gives the wrong results because I've
> chosen a u32 type instead of u64, that's just as much a bug as using i32
> instead of i64.

I don't think *anyone* considers a program that produces the wrong
result to be have any less buggy simply because of the types used.  You
are ascribing to other views that I have never seen anyone express.

-- 
Ben.

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What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-07-31 10:55 -0300
  Re: What is your opinion about unsigned int u = -2 ? Ben Bacarisse <ben@bsb.me.uk> - 2024-07-31 20:29 +0100
    Re: What is your opinion about unsigned int u = -2 ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-11 12:33 -0700
      Re: What is your opinion about unsigned int u = -2 ? Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-11 21:08 +0100
        Re: What is your opinion about unsigned int u = -2 ? Richard Damon <richard@damon-family.org> - 2024-08-11 16:45 -0400
        Re: What is your opinion about unsigned int u = -2 ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-08-11 16:53 -0400
          Re: What is your opinion about unsigned int u = -2 ? Vir Campestris <vir.campestris@invalid.invalid> - 2024-08-12 11:47 +0100
        Re: What is your opinion about unsigned int u = -2 ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-11 23:07 -0700
  Re: What is your opinion about unsigned int u = -2 ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-31 17:17 -0400
  Re: What is your opinion about unsigned int u = -2 ? Blue-Maned_Hawk <bluemanedhawk@invalid.invalid> - 2024-08-01 06:34 +0000
    Re: What is your opinion about unsigned int u = -2 ? Ben Bacarisse <ben@bsb.me.uk> - 2024-08-01 12:02 +0100
      Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 10:36 -0300
        Re: What is your opinion about unsigned int u = -2 ? gazelle@shell.xmission.com (Kenny McCormack) - 2024-08-02 14:33 +0000
          Re: What is your opinion about unsigned int u = -2 ? Bart <bc@freeuk.com> - 2024-08-02 15:48 +0100
            Re: What is your opinion about unsigned int u = -2 ? Ben Bacarisse <ben@bsb.me.uk> - 2024-08-02 16:17 +0100
            Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 15:39 -0300
              Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 15:58 -0300
            Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-02 11:48 -0700
              Re: What is your opinion about unsigned int u = -2 ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-08-02 15:21 -0400
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 22:03 -0300
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 22:12 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-02 18:31 -0700
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 22:50 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-02 19:29 -0700
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-03 09:36 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-03 16:10 -0700
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-03 22:46 -0300
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-03 23:04 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-02 18:25 -0700
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 22:44 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-02 19:04 -0700
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-02 23:27 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-02 19:40 -0700
                Re: What is your opinion about unsigned int u = -2 ? David Brown <david.brown@hesbynett.no> - 2024-08-03 19:43 +0200
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-03 14:46 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-03 16:52 -0700
                Re: What is your opinion about unsigned int u = -2 ? David Brown <david.brown@hesbynett.no> - 2024-08-03 19:34 +0200
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-03 14:51 -0300
                Re: What is your opinion about unsigned int u = -2 ? Thiago Adams <thiago.adams@gmail.com> - 2024-08-03 15:30 -0300
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-03 16:46 -0700
                Re: What is your opinion about unsigned int u = -2 ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-08-11 13:57 -0700
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-11 14:53 -0700
                Re: What is your opinion about unsigned int u = -2 ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-08-03 16:19 -0700
              Re: What is your opinion about unsigned int u = -2 ? Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-09 20:10 +0200
            Re: What is your opinion about unsigned int u = -2 ? David Brown <david.brown@hesbynett.no> - 2024-08-03 19:17 +0200
          Re: What is your opinion about unsigned int u = -2 ? Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-04 20:29 +0200
            Re: What is your opinion about unsigned int u = -2 ? Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-08-07 23:48 +0000
              Re: What is your opinion about unsigned int u = -2 ? David Brown <david.brown@hesbynett.no> - 2024-08-08 19:47 +0200
                Re: What is your opinion about unsigned int u = -2 ? Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-09 20:08 +0200
                Re: What is your opinion about unsigned int u = -2 ? David Brown <david.brown@hesbynett.no> - 2024-08-09 20:19 +0200
                Re: What is your opinion about unsigned int u = -2 ? Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-09 21:18 +0200
                Re: What is your opinion about unsigned int u = -2 ? David Brown <david.brown@hesbynett.no> - 2024-08-09 21:40 +0200
                Re: What is your opinion about unsigned int u = -2 ? Richard Damon <richard@damon-family.org> - 2024-08-09 21:16 -0400
    Re: What is your opinion about unsigned int u = -2 ? Bonita Montero <Bonita.Montero@gmail.com> - 2024-08-04 18:16 +0200

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