Re: How to add ssize_t a by size_t b?

From	Manfred <noname@add.invalid>
Newsgroups	comp.lang.c
Subject	Re: How to add ssize_t a by size_t b?
Date	2021-10-02 20:17 +0200
Organization	Aioe.org NNTP Server
Message-ID	<sja7ni$1445$1@gioia.aioe.org> (permalink)
References	(1 earlier) <sj7h4g$19gs$1@gioia.aioe.org> <JtI5J.65761$ol1.6157@fx42.iad> <87pmsoh1st.fsf@nosuchdomain.example.com> <sj88eh$aub$1@dont-email.me> <87lf3cgq2u.fsf@nosuchdomain.example.com>

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On 10/2/2021 3:42 AM, Keith Thompson wrote:
> James Kuyper <jameskuyper@alumni.caltech.edu> writes:
>> On 10/1/21 5:29 PM, Keith Thompson wrote:
>>> scott@slp53.sl.home (Scott Lurndal) writes:
>>>> Guillaume <message@bottle.org> writes:
>>> [...]
>>>>> ssize_t is not standard C. It's defined in POSIX.
>>>>> While it's a signed integer, whereas size_t is unsigned, I don't know
>>>>> how it relates to size_t on a given implementation in terms of width.
>>>>
>>>> POSIX specifies that sizeof(ssize_t) == sizeof(size_t).
>>>
>>> Does it?  I couldn't find any such guarantee.
>>>
>>> https://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_types.h.html
>>
>> In <https://pubs.opengroup.org/onlinepubs/9699919799/toc.htm> it says
>> the following about ssize_t:
>>
>> "The wording is such that an implementation may either choose to use a
>> longer type or simply to use the signed version of the type that
>> underlies size_t."
>>
>> Therefore, sizeof(ssize_t) > sizeof(size_t) is allowed. I have not yet
>> located "the wording" that referred to above.
> 
> Because of the way the site uses frames, that URL isn't meaningful.  The
> quote is from
> https://pubs.opengroup.org/onlinepubs/9699919799/xrat/V4_xsh_chap02.html
> 
> I couldn't find "the wording" either.
> 

Maybe the 'wording' is "a signed analog of size_t"?

Thread

How to add ssize_t a by size_t b? wij <wyniijj@gmail.com> - 2021-10-01 08:32 -0700
  Re: How to add ssize_t a by size_t b? Guillaume <message@bottle.org> - 2021-10-01 19:39 +0200
    Re: How to add ssize_t a by size_t b? scott@slp53.sl.home (Scott Lurndal) - 2021-10-01 18:31 +0000
      Re: How to add ssize_t a by size_t b? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-01 14:29 -0700
        Re: How to add ssize_t a by size_t b? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-01 20:17 -0400
          Re: How to add ssize_t a by size_t b? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-01 18:42 -0700
            Re: How to add ssize_t a by size_t b? Manfred <noname@add.invalid> - 2021-10-02 20:17 +0200
              Re: How to add ssize_t a by size_t b? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-02 15:03 -0400
    Re: How to add ssize_t a by size_t b? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-10-01 14:53 -0400
      Re: How to add ssize_t a by size_t b? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-02 15:13 -0700
  Re: How to add ssize_t a by size_t b? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-01 14:13 -0700
    Re: How to add ssize_t a by size_t b? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-02 14:52 -0700
  Re: How to add ssize_t a by size_t b? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-02 14:47 -0700
  Re: How to add ssize_t a by size_t b? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-06 04:06 -0700

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