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Re: New features added into C23 standard

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Thiago Adams <thiago.adams@gmail.com> writes:
> On Monday, July 25, 2022 at 5:49:30 PM UTC-3, Thiago Adams wrote:
>> It's hard to believe how nullptr was accepted. 
>> https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3039.htm 
>> The same for auto and constexpr.
>
> In 2018 I suggested nullptr 
>
> https://groups.google.com/g/comp.lang.c/c/YJmom4rC2FI/m/DJzGmwXmCQAJ
>
> In 2019 I replied my own message saying that was a bad idea.
> https://groups.google.com/g/comp.lang.c/c/YJmom4rC2FI/m/Daz0AvxHAwAJ
>
> I agree  with myself from 2019.
> "
> One difference between adding _Bool into the language is that BOOL
> was never added into the language headers. (Am I right? I didn't find
> BOOL or TRUE FALSE at the language specification).
>
> On the other hand if you search for NULL at the standard you will
> find that NULL is defined in stddef.h
>
> This means that adding _Bool didn't added a new way to declare booleans,
> but adding nullptr will create this confusion that is two ways of
> writing code that means NULL.
>
> In C we also have different ((void*)0) conversion rules compared with
> C++ that is more strict.
>
> Then for C, I believe that the literal that corresponds nullptr already
> exists and it is ((void*)0).
>
> What could be done is adding flags to static analysis to decide what
> to do with ((void*)0) conversions. 
> "

I don't see the problem.  There are already arbitrarily many ways to
write a null pointer constant in C.  For example, '\0' '-'-'-', and
0x0ULL are all null pointer constants.

A null pointer constant can be of any integer type, or of type void*.

Adding nullptr and nullptr_t adds one more form of null pointer
constant, and an unambiguous type for nullptr.  Of course NULL and
(void*)0 are still valid, because invalidating them would break tons of
existing code -- but nullptr is the new preferred way to write a null
pointer constant.  Old code is still valid, but new code can be cleaner
-- and if a user writes nullptr, there's no question that it was
*intended* to be a null pointer constant, which could result in clearer
diagnostic messages.

(It's likely that if the language were being defined from scratch,
nullptr would be the *only* way to write a null pointer constant.  The
stuff about using integer constant expressions exists only for backward
compatibility, and we're stuck with it.)

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
Working, but not speaking, for Philips
void Void(void) { Void(); } /* The recursive call of the void */

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New features added into C23 standard Thiago Adams <thiago.adams@gmail.com> - 2022-07-22 12:32 -0700
  Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-07-22 23:15 +0100
  Re: New features added into C23 standard Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-23 01:31 -0700
    Re: New features added into C23 standard gazelle@shell.xmission.com (Kenny McCormack) - 2022-07-23 10:10 +0000
  Re: New features added into C23 standard Thiago Adams <thiago.adams@gmail.com> - 2022-07-25 13:49 -0700
    Re: New features added into C23 standard Thiago Adams <thiago.adams@gmail.com> - 2022-07-25 13:57 -0700
      Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-25 14:50 -0700
        Re: New features added into C23 standard Thiago Adams <thiago.adams@gmail.com> - 2022-07-25 15:51 -0700
          Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-25 18:04 -0700
            Re: New features added into C23 standard Thiago Adams <thiago.adams@gmail.com> - 2022-07-25 19:23 -0700
              Re: New features added into C23 standard Opus <ifonly@youknew.org> - 2022-07-26 05:13 +0200
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-25 23:36 -0400
                Re: New features added into C23 standard Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-07-25 21:52 -0700
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-26 11:44 -0700
              Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-26 11:39 -0700
          Re: New features added into C23 standard David Brown <david.brown@hesbynett.no> - 2022-07-30 14:42 +0200
            Re: New features added into C23 standard scott@slp53.sl.home (Scott Lurndal) - 2022-07-30 15:18 +0000
              Re: New features added into C23 standard Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-30 09:13 -0700
            Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-07-30 17:31 +0100
              Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-30 16:46 -0700
            Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-30 14:36 -0700
              Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-30 18:15 -0400
                Re: New features added into C23 standard Kaz Kylheku <480-992-1380@kylheku.com> - 2022-07-30 23:28 +0000
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-31 16:48 -0700
                Re: New features added into C23 standard Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-31 22:42 -0700
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-31 23:25 -0700
                Re: New features added into C23 standard Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-08-01 00:10 -0700
                Re: New features added into C23 standard David Brown <david.brown@hesbynett.no> - 2022-08-01 09:55 +0200
                Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-08-01 20:17 +0100
              Re: New features added into C23 standard Kaz Kylheku <480-992-1380@kylheku.com> - 2022-07-30 23:21 +0000
        Re: New features added into C23 standard Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-25 22:59 -0700
          Re: New features added into C23 standard Öö Tiib <ootiib@hot.ee> - 2022-07-26 00:48 -0700
            Re: New features added into C23 standard Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-26 02:08 -0700
              Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-26 06:59 -0400
              Re: New features added into C23 standard Öö Tiib <ootiib@hot.ee> - 2022-07-26 04:02 -0700
                Re: New features added into C23 standard Vir Campestris <vir.campestris@invalid.invalid> - 2022-07-29 21:18 +0100
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-29 16:55 -0700
              Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-26 11:51 -0700
            Re: New features added into C23 standard David Brown <david.brown@hesbynett.no> - 2022-07-31 11:12 +0200
              Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-31 07:40 -0400
                Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-07-31 17:40 +0100
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-31 12:56 -0400
                Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-07-31 19:28 +0100
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-31 14:52 -0400
                Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-07-31 21:35 +0100
                Re: New features added into C23 standard Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-08-15 23:24 -0700
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-31 16:57 -0700
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-31 16:55 -0700
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-31 20:09 -0400
                Re: New features added into C23 standard Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-08-15 22:52 -0700
                Re: New features added into C23 standard David Brown <david.brown@hesbynett.no> - 2022-08-16 09:21 +0200
                Re: New features added into C23 standard Philipp Klaus Krause <pkk@spth.de> - 2022-08-16 09:32 +0200
                Re: New features added into C23 standard David Brown <david.brown@hesbynett.no> - 2022-08-16 11:06 +0200
                Re: New features added into C23 standard Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-08-15 23:17 -0700
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-08-17 20:11 -0400
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-08-17 20:08 -0700
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-08-17 23:19 -0400
                Re: New features added into C23 standard Kaz Kylheku <480-992-1380@kylheku.com> - 2022-08-18 07:03 +0000
                Re: New features added into C23 standard Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-08-23 09:43 -0700
                Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-08-23 11:02 -0700
                Re: New features added into C23 standard Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-08-23 13:40 -0700
          Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-26 07:04 -0400
            Re: New features added into C23 standard Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-26 05:24 -0700
              Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-26 22:30 -0400
                Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-07-29 00:02 +0100
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-28 21:20 -0400
                Re: New features added into C23 standard William Ahern <william@25thandClement.com> - 2022-07-28 19:36 -0700
                Re: New features added into C23 standard scott@slp53.sl.home (Scott Lurndal) - 2022-07-29 16:39 +0000
                Re: New features added into C23 standard Richard Damon <Richard@Damon-Family.org> - 2022-07-29 18:55 -0400
                Re: New features added into C23 standard Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-07-29 15:17 +0100
          Re: New features added into C23 standard scott@slp53.sl.home (Scott Lurndal) - 2022-07-26 13:27 +0000
          Re: New features added into C23 standard Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-07-26 11:47 -0700
            Re: New features added into C23 standard Kaz Kylheku <480-992-1380@kylheku.com> - 2022-07-26 20:27 +0000
              Re: New features added into C23 standard Philipp Klaus Krause <pkk@spth.de> - 2022-08-16 08:42 +0200
  Re: New features added into C23 standard Bonita Montero <Bonita.Montero@gmail.com> - 2022-07-26 05:37 +0200
    Re: New features added into C23 standard Lynn McGuire <lynnmcguire5@gmail.com> - 2022-07-28 16:47 -0500
      Re: New features added into C23 standard Bonita Montero <Bonita.Montero@gmail.com> - 2022-07-29 07:14 +0200
        Re: New features added into C23 standard Vir Campestris <vir.campestris@invalid.invalid> - 2022-07-29 21:21 +0100
  Re: New features added into C23 standard Grant Mulholland <grantlmul@gmail.com> - 2022-08-13 22:21 -0700
    Re: New features added into C23 standard Lynn McGuire <lynnmcguire5@gmail.com> - 2022-08-15 21:21 -0500
      Re: New features added into C23 standard Bonita Montero <Bonita.Montero@gmail.com> - 2022-08-16 08:39 +0200
    Re: New features added into C23 standard Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-08-15 22:54 -0700
    Re: New features added into C23 standard Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-08-18 12:03 -0700
      Re: New features added into C23 standard "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-08-18 12:56 -0700
      Re: New features added into C23 standard William Ahern <william@25thandClement.com> - 2022-08-18 16:07 -0700
        Re: New features added into C23 standard Thiago Adams <thiago.adams@gmail.com> - 2022-08-18 18:47 -0700
          Re: New features added into C23 standard Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-08-18 20:23 -0700

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