Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c > #69709

Re: counting bytes

From Keith Thompson <kst-u@mib.org>
Newsgroups comp.lang.c
Subject Re: counting bytes
Date 2015-09-06 17:46 -0700
Organization None to speak of
Message-ID <lnfv2rt5rw.fsf@kst-u.example.com> (permalink)
References (16 earlier) <kfnegjc7idc.fsf@x-alumni2.alumni.caltech.edu> <HkPxx.24150$bC.22991@fx11.iad> <kfn8u8kyf9t.fsf@x-alumni2.alumni.caltech.edu> <lnpp1wuvpo.fsf@kst-u.example.com> <kfnfv2rqlck.fsf@x-alumni2.alumni.caltech.edu>

Show all headers | View raw

Tim Rentsch <txr@alumni.caltech.edu> writes:
> Keith Thompson <kst-u@mib.org> writes:
>> Tim Rentsch <txr@alumni.caltech.edu> writes:
>>> Richard Damon <Richard@Damon-Family.org> writes:
>>
>> [...]
>>
>>>> UINT8_MAX has only one allowed value, 255, any other value (other than
>>>> not defined) is non-conforming.  (The fixed sized maxes are a bit
>>>> strange only having a single possible value).
>>>
>>> I won't disagree, but even so the Standard says the value is
>>> implementation-defined.  Look it up if you don't believe me -
>>> it's listed in both 7.20.3 and J.3.13.
>>
>> N1570 7.20.3 doesn't mention UINT8_MAX.
>
> Sorry, I had the wrong section.  It's 7.20.2.
>
>> It's mentioned implicitly in 7.20.2.1, which says that UINTN_MAX
>> is exactly 2^N-1, not that it's implementation-defined.
>
> Please see 7.20.2 p2, which does.

    Its implementation-defined value shall be equal to or greater in
    magnitude (absolute value) than the corresponding value given below,
    with the same sign, except where stated to be exactly the given
    value.

I think that's just a bit of sloppy wording.

3.19.1 defines an "implementation-defined value" as an "unspecified
value where each implementation documents how the choice is made",
and an "unspecified value" as a "valid value of the relevant type
where this International Standard imposes no requirements on which
value is chosen in any instance".  So the value of INT_LEAST8_MAX,
for example, is said to be "implementation-defined", but that
contradicts the definition of the term, since the standard does
impose *some* requirements on which value can be chosen (it can't
be 42, for example).

IMHO the fix for that would be to tweak the definition of
"implementation-defined value", so it can apply to values for
which the standard imposes *some* requirements without requiring
one specific value.

The most literal reading of 7.20.2p2 is that the value of
UINT8_MAX is implementation-defined.  A more sensible reading,
IMHO, is that values that are stated to have exact values are *not*
implementation-defined.  That requires a slightly strained parsing
of the sentence.

I would not consider an implementation to be non-conforming because
it doesn't document the value of UINT8_MAX.

-- 
Keith Thompson (The_Other_Keith) kst-u@mib.org  <http://www.ghoti.net/~kst>
Working, but not speaking, for JetHead Development, Inc.
"We must do something.  This is something.  Therefore, we must do this."
    -- Antony Jay and Jonathan Lynn, "Yes Minister"

Back to comp.lang.c | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

counting bytes bilsch01 <king621@comcast.net> - 2015-06-06 04:58 -0700
  Re: counting bytes Bartc <bc@freeuk.com> - 2015-06-06 13:05 +0100
    Re: counting bytes bilsch01 <king621@comcast.net> - 2015-06-06 05:24 -0700
      Re: counting bytes Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-06-06 05:41 -0700
        Re: counting bytes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-06 14:00 +0100
      Re: counting bytes Bartc <bc@freeuk.com> - 2015-06-06 13:52 +0100
      Re: counting bytes Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2015-06-06 10:27 -0400
        Re: counting bytes jt@toerring.de (Jens Thoms Toerring) - 2015-06-06 22:31 +0000
          THANKS EVERYBODY FOR THE INFO bilsch01 <king621@comcast.net> - 2015-06-06 23:35 -0700
            Re: THANKS EVERYBODY FOR THE INFO Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-07 10:08 +0100
              Re: THANKS EVERYBODY FOR THE INFO Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-06-07 09:22 -0700
                Re: THANKS EVERYBODY FOR THE INFO Ben Bacarisse <ben.usenet@bsb.me.uk> - 2015-06-07 18:07 +0100
                Re: THANKS EVERYBODY FOR THE INFO Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-06-08 04:03 -0700
                Re: THANKS EVERYBODY FOR THE INFO Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-11 08:12 -0700
            Re: THANKS EVERYBODY FOR THE INFO Keith Thompson <kst-u@mib.org> - 2015-06-07 08:01 -0700
          Re: counting bytes gordonb.3gcai@burditt.org (Gordon Burditt) - 2015-06-07 05:02 -0500
          Re: counting bytes David Brown <david.brown@hesbynett.no> - 2015-06-07 15:32 +0200
            Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-06-07 12:48 -0700
              Re: counting bytes David Brown <david.brown@hesbynett.no> - 2015-06-07 23:05 +0200
                Re: counting bytes Richard Heathfield <rjh@cpax.org.uk> - 2015-06-07 22:17 +0100
                Re: counting bytes David Brown <david.brown@hesbynett.no> - 2015-06-07 23:49 +0200
                Re: counting bytes Richard Heathfield <rjh@cpax.org.uk> - 2015-06-07 23:37 +0100
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-11 08:25 -0700
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-11 08:21 -0700
                Re: counting bytes Martin Shobe <martin.shobe@yahoo.com> - 2015-07-11 13:54 -0500
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-20 06:33 -0700
                Re: counting bytes Martin Shobe <martin.shobe@yahoo.com> - 2015-07-20 09:51 -0500
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-24 09:49 -0700
                Re: counting bytes Martin Shobe <martin.shobe@yahoo.com> - 2015-07-24 12:26 -0500
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-30 11:16 -0700
                Re: counting bytes Martin Shobe <martin.shobe@yahoo.com> - 2015-07-30 23:15 -0500
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-08-02 06:07 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-08-02 14:31 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-08-09 05:31 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-08-09 17:09 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-05 09:58 -0700
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-09-05 19:29 -0700
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-06 14:38 -0700
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-09-06 17:46 -0700
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-07 23:50 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-09-06 22:00 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-07 23:24 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-07-24 20:03 -0400
                Re: counting bytes Martin Shobe <martin.shobe@yahoo.com> - 2015-07-24 22:13 -0500
                Re: counting bytes Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-25 02:22 -0700
                Re: counting bytes Martin Shobe <martin.shobe@yahoo.com> - 2015-07-25 11:39 -0500
                Re: counting bytes Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-25 09:48 -0700
                Re: counting bytes Martin Shobe <martin.shobe@yahoo.com> - 2015-07-25 14:04 -0500
                Re: counting bytes Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-25 14:22 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-07-25 11:07 -0400
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-25 12:43 -0400
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-07-25 13:32 -0400
                Re: counting bytes glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-25 20:14 +0000
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-25 17:24 -0400
                Re: counting bytes Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-25 14:42 -0700
                Re: counting bytes glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-25 23:02 +0000
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-25 19:17 -0400
                Re: counting bytes Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-25 16:37 -0700
                Re: counting bytes glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-26 06:10 +0000
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-26 08:31 -0400
                Re: counting bytes Bartc <bc@freeuk.com> - 2015-07-30 21:32 +0100
                Re: counting bytes raltbos@xs4all.nl (Richard Bos) - 2015-07-31 13:25 +0000
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-31 11:31 -0400
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-07-31 11:30 -0700
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-31 14:29 -0400
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-07-31 12:14 -0700
                Re: counting bytes David Kleinecke <dkleinecke@gmail.com> - 2015-07-31 17:39 -0700
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-31 23:32 -0400
                Re: counting bytes David Kleinecke <dkleinecke@gmail.com> - 2015-08-01 16:41 -0700
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-08-01 20:23 -0400
                Re: counting bytes Malcolm McLean <malcolm.mclean5@btinternet.com> - 2015-07-31 11:01 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-07-25 19:42 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-30 12:16 -0700
                Re: counting bytes Bartc <bc@freeuk.com> - 2015-07-30 22:04 +0100
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-08-02 06:10 -0700
                Re: counting bytes David Kleinecke <dkleinecke@gmail.com> - 2015-07-25 19:10 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-07-25 22:16 -0400
                Re: counting bytes David Kleinecke <dkleinecke@gmail.com> - 2015-07-25 19:46 -0700
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-30 11:52 -0700
                Re: counting bytes raltbos@xs4all.nl (Richard Bos) - 2015-07-31 08:51 +0000
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-08-02 06:19 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-08-01 09:39 -0400
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-08-01 13:06 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-08-01 20:43 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-08-02 06:52 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-08-02 15:14 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-08-09 07:54 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-08-09 16:43 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-09-05 10:48 -0700
                Re: counting bytes Richard Damon <Richard@Damon-Family.org> - 2015-07-11 17:50 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-20 06:36 -0700
                Re: counting bytes raltbos@xs4all.nl (Richard Bos) - 2015-07-20 15:14 +0000
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-24 09:38 -0700
                Re: counting bytes raltbos@xs4all.nl (Richard Bos) - 2015-07-25 19:12 +0000
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-30 12:18 -0700
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-07-11 17:03 -0700
                Re: counting bytes glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-12 00:15 +0000
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-07-11 17:42 -0700
                Re: counting bytes glen herrmannsfeldt <gah@ugcs.caltech.edu> - 2015-07-12 02:46 +0000
                Re: counting bytes James Kuyper <jameskuyper@verizon.net> - 2015-07-12 12:33 -0400
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-20 06:48 -0700
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-07-20 11:18 -0700
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-24 09:58 -0700
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-07-24 11:14 -0700
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-07-30 11:02 -0700
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-07-30 13:10 -0700
                Re: counting bytes Tim Rentsch <txr@alumni.caltech.edu> - 2015-08-01 10:53 -0700
                Re: counting bytes Keith Thompson <kst-u@mib.org> - 2015-06-07 14:46 -0700
                Re: counting bytes David Brown <david.brown@hesbynett.no> - 2015-06-08 09:05 +0200
  Re: counting bytes Siri Cruz <chine.bleu@yahoo.com> - 2015-06-06 05:06 -0700
  Re: counting bytes bartekltg <bartekltg@gmail.com> - 2015-07-26 00:58 +0200
    Re: counting bytes bartekltg <bartekltg@gmail.com> - 2015-07-26 01:00 +0200

csiph-web