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Re: How to add ssize_t a by size_t b?

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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.

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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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