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Re: CHAR_BIT is not eight

From Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups comp.lang.c++
Subject Re: CHAR_BIT is not eight
Date 2022-12-05 11:42 -0800
Organization A noiseless patient Spider
Message-ID <86359t63ie.fsf@linuxsc.com> (permalink)
References (4 earlier) <ti95jj$1qbd8$1@dont-email.me> <tiatim$68g$1@gioia.aioe.org> <tiausq$21bt8$1@dont-email.me> <86r0y3c8yg.fsf@linuxsc.com> <87mt8qkan0.fsf@nosuchdomain.example.com>

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Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

> Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
>
>> Paavo Helde <eesnimi@osa.pri.ee> writes:
>>
>>> 14.10.2022 08:54 Juha Nieminen kirjutas:
>>>
>>>> David Brown <david.brown@hesbynett.no> wrote:
>>>>
>>>>> It is very rare that "as portable as possible" is a realistic
>>>>> specification.  It happens, but it is not common.
>>>>
>>>> "Not common" does not mean "you shouldn't care", when you are writing
>>>> a library that could potentially be used in more exotic architectures,
>>>> such as the one mentioned in this thread.
>>>>
>>>> For example if you are writing, say, a small library that
>>>> calculates hashes or checksums using a particular algorithm.  It's
>>>> not at all unrealistic that such a library could have uses in these
>>>> more exotic microcontrollers (as microcontrollers are often used in
>>>> embedded systems that handle data somehow, and might be interested
>>>> in calculating things like checksums and hashes).  And it is quite
>>>> likely that such an algorithm might care about bit sizes.
>>>
>>> True, but for really supporting such exotic platforms one would need
>>> to run tests on these platforms (or at least in an emulator) during
>>> the development and potentially also later if anything changes.
>>
>> Perhaps some tests, but not necessarily all tests.  Any parts of
>> the program that are verifiably platform agnostic would not need
>> platform-specific re-testing.  Also, any platform-specific tests
>> don't have to be run during development, but only just before the
>> program is deployed on the exotic platforms in question, which
>> could be significantly later than the original development.
>
> How do you know that a part of program is "verifiably platform
> agnostic" without platform-specific testing?  How else would that
> be verified?

Testing can be used to show the presence of bugs, but never their
absence.  The same principle applies to determining whether code
is platform agnostic.  Showing that part of a program is platform
agnostic can be done using formal methods and formal semantics,
just like other kinds of formal verification.  It can be more
work to take into account the range of variation allowed by
platform variability, but the principles involved are the same.

>>> Software without tests is just a work of literature.
>>
>> A hyperbolic statement if ever there was one.
>
> Sure, but only slightly hyperbolic.

On the contrary, more hyperbolic than most.  That is the meaning of
the sentence "a hyperbolic statement if ever there was one."

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Thread

CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-12 15:57 -0700
  Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-12 16:01 -0700
  Re: CHAR_BIT is not eight Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-10-12 17:16 -0700
    Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 11:38 +0200
    Re: CHAR_BIT is not eight Michael S <already5chosen@yahoo.com> - 2022-11-16 06:24 -0800
      Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-17 11:04 +0100
        Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-11-17 16:40 +0000
          Re: CHAR_BIT is not eight Richard Damon <Richard@Damon-Family.org> - 2022-11-17 23:23 -0500
            Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-18 08:16 +0100
              Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-11-18 16:33 +0000
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-18 18:54 +0100
            Re: CHAR_BIT is not eight Michael S <already5chosen@yahoo.com> - 2022-11-18 03:47 -0800
              Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-11-18 14:52 +0000
            Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-11-18 16:32 +0000
              Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-18 19:05 +0100
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-11-18 18:16 +0000
  Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-13 08:02 +0000
    Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-13 08:08 +0000
      Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 11:35 +0200
        Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 02:53 -0700
          Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 11:57 +0200
            Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 03:05 -0700
            Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-17 06:18 +0000
            Re: CHAR_BIT is not eight Lynn McGuire <lynnmcguire5@gmail.com> - 2022-10-17 15:29 -0500
    Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-13 02:06 -0700
      Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 11:42 +0200
        Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-13 15:36 +0000
          Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 23:06 +0200
            Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-13 22:30 +0100
              Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-14 15:27 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-14 14:47 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-14 14:58 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-14 21:01 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 10:28 +0000
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-15 13:39 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 12:45 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:18 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:24 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:34 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:39 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:53 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:55 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:57 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:59 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-17 15:27 +0000
                Re: CHAR_BIT is not eight "daniel...@gmail.com" <danielaparker@gmail.com> - 2022-10-17 09:04 -0700
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-17 16:13 +0000
                Re: CHAR_BIT is not eight red floyd <no.spam.here@its.invalid> - 2022-10-17 09:44 -0700
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-17 17:47 +0100
                Re: CHAR_BIT is not eight Manfred <noname@add.invalid> - 2022-10-18 01:10 +0200
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-17 16:22 -0700
                Re: CHAR_BIT is not eight Paul N <gw7rib@aol.com> - 2022-10-18 05:13 -0700
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-18 15:04 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-18 17:40 +0100
                Re: CHAR_BIT is not eight "daniel...@gmail.com" <danielaparker@gmail.com> - 2022-10-18 12:14 -0700
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-19 15:12 +0000
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-10-19 15:35 +0000
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-20 16:16 +0000
                Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 20:13 +0200
                Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 20:11 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 20:03 +0100
                Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-16 07:51 +0200
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 17:03 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 16:34 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 18:51 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 18:11 +0100
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 19:18 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 22:02 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 21:19 +0100
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-10-16 21:24 +0000
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 14:38 -0700
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 14:48 -0700
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 22:39 +0100
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-10-16 23:49 +0000
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-17 09:54 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-17 17:31 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-17 19:56 +0200
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-17 15:29 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-17 17:33 +0100
                Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 11:55 -0700
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-15 13:06 -0700
                Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 15:42 -0700
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 19:10 +0200
                Re: CHAR_BIT is not eight Vir Campestris <vir.campestris@invalid.invalid> - 2022-10-16 21:28 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-17 10:09 +0200
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 13:35 -0700
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 13:36 -0700
      Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-11-02 17:46 -0700
    Re: CHAR_BIT is not eight Bo Persson <bo@bo-persson.se> - 2022-10-13 11:10 +0200
      Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-13 10:49 +0000
        Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-13 12:05 +0000
          Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-13 06:34 -0700
          Re: CHAR_BIT is not eight Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-10-13 15:24 +0100
        Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 15:59 +0200
          Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-14 05:54 +0000
            Re: CHAR_BIT is not eight Paavo Helde <eesnimi@osa.pri.ee> - 2022-10-14 09:16 +0300
              Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-11-16 05:41 -0800
                Re: CHAR_BIT is not eight Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-16 10:38 -0800
                Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-05 11:42 -0800
                Re: CHAR_BIT is not eight Öö Tiib <ootiib@hot.ee> - 2022-12-06 01:03 -0800
                Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-28 20:49 -0800
            Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-14 00:17 -0700
              Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-14 15:33 +0200
              Re: CHAR_BIT is not eight Vir Campestris <vir.campestris@invalid.invalid> - 2022-10-16 21:37 +0100
                Re: CHAR_BIT is not eight Lynn McGuire <lynnmcguire5@gmail.com> - 2022-10-17 15:24 -0500
  Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 11:34 +0200

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