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Re: standard error messages in a std::string or in a const char *

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On 9/11/2019 2:27 PM, James Kuyper wrote:
> On 9/11/19 7:43 AM, Öö Tiib wrote:
>> On Wednesday, 11 September 2019 12:48:03 UTC+3, Bonita Montero  wrote:
>>> There's strerror_r, which is thread-safe.
>>
>> Somewhere there is strerror_r but not in C++ standard. ...
> 
> Such a function is specified by POSIX, which doesn't help those
> targeting non-POSIX systems.
> 
>> ... In C++ standard
>> there was added strerror_s by C++11 but it may be is deprecated again.
> 
> It is still mentioned in N4659.pdf, dated 2017-03-01. It is described in
> 20.1.5.2p10 as a carry-over from C. There is no other description,
> you're supposed to cross-reference the C standard for that.
> 
> The description of sterror_s() in the C standard (C11 K3.7.4.2) does
> not, itself, say anything about threads. It simply lacks any clause
> comparable to the one in the description of sterror() description which
> says "The strerror function is not required to avoid data races with
> other calls to the strerror function." (C11 7.24.6.2p3). That's
> sufficient, since "Unless explicitly stated otherwise in the detailed
> descriptions that follow, library functions shall prevent data races."
> (C11 7.1.4p5).
> 
> Just in case you didn't notice that omission, footnote 312 on the
> description of strerror() says "The strerror_s function can be used
> instead to avoid data races.".
> 

strerror_s is indeed part of annex K, which has become more and more 
controversial, and some implementations (notably glibc) do not support it.
However, a good indication that it is thread safe comes from its 
interface: instead of returning a pointer to an internal string buffer, 
it requires a writable buffer to be provided by the caller.

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standard error messages in a std::string or in a const char * Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-11 00:35 +0200
  Re: standard error messages in a std::string or in a const char * Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-11 00:37 +0200
    Re: standard error messages in a std::string or in a const char * Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-09-11 08:28 +0000
      Re: standard error messages in a std::string or in a const char * Juha Nieminen <nospam@thanks.invalid> - 2019-09-11 08:58 +0000
        Re: standard error messages in a std::string or in a const char * Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-11 11:09 +0200
          Re: standard error messages in a std::string or in a const char * Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-11 11:37 +0200
        Re: standard error messages in a std::string or in a const char * Keith Thompson <kst-u@mib.org> - 2019-09-11 02:37 -0700
          Re: standard error messages in a std::string or in a const char * Bonita Montero <Bonita.Montero@gmail.com> - 2019-09-11 11:47 +0200
            Re: standard error messages in a std::string or in a const char * Öö Tiib <ootiib@hot.ee> - 2019-09-11 04:43 -0700
              Re: standard error messages in a std::string or in a const char * James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-09-11 08:27 -0400
                Re: standard error messages in a std::string or in a const char * Manfred <noname@add.invalid> - 2019-09-11 14:56 +0200
                Re: standard error messages in a std::string or in a const char * Daniel <danielaparker@gmail.com> - 2019-09-11 07:00 -0700
          Re: standard error messages in a std::string or in a const char * Thiago Adams <thiago.adams@gmail.com> - 2019-09-11 09:44 -0700
          Re: standard error messages in a std::string or in a const char * Jorgen Grahn <grahn+nntp@snipabacken.se> - 2019-09-12 10:21 +0000
            Re: standard error messages in a std::string or in a const char * Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-12 13:05 +0200
        Re: standard error messages in a std::string or in a const char * Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-11 17:43 +0200
          Re: standard error messages in a std::string or in a const char * Paavo Helde <myfirstname@osa.pri.ee> - 2019-09-11 19:23 +0300
            Re: standard error messages in a std::string or in a const char * Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-11 19:19 +0200
              Re: standard error messages in a std::string or in a const char * Paavo Helde <myfirstname@osa.pri.ee> - 2019-09-11 20:32 +0300
                Re: standard error messages in a std::string or in a const char * Soviet_Mario <SovietMario@CCCP.MIR> - 2019-09-12 13:08 +0200
                Re: standard error messages in a std::string or in a const char * Thiago Adams <thiago.adams@gmail.com> - 2019-09-12 04:29 -0700
                Re: standard error messages in a std::string or in a const char * Keith Thompson <kst-u@mib.org> - 2019-09-12 14:41 -0700
              Re: standard error messages in a std::string or in a const char * Thiago Adams <thiago.adams@gmail.com> - 2019-09-11 10:39 -0700
              Re: standard error messages in a std::string or in a const char * James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-09-11 19:50 -0400
                Re: standard error messages in a std::string or in a const char * Keith Thompson <kst-u@mib.org> - 2019-09-11 17:11 -0700
                Re: standard error messages in a std::string or in a const char * James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-09-11 20:23 -0400
                Re: standard error messages in a std::string or in a const char * David Brown <david.brown@hesbynett.no> - 2019-09-12 11:21 +0200
                Re: standard error messages in a std::string or in a const char * James Kuyper <jameskuyper@alumni.caltech.edu> - 2019-09-12 07:31 -0400
                Re: standard error messages in a std::string or in a const char * Manfred <noname@add.invalid> - 2019-09-12 15:44 +0200

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