Re: question about nullptr

From	Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups	comp.lang.c
Subject	Re: question about nullptr
Date	2024-07-08 22:58 -0700
Organization	None to speak of
Message-ID	<87y16bw1hf.fsf@nosuchdomain.example.com> (permalink)
References	(5 earlier) <2ckiO.19403$7Ej.4487@fx46.iad> <87plrpt4du.fsf@bsb.me.uk> <9bCiO.7108$sXW9.3805@fx41.iad> <877cdwu9s1.fsf@nosuchdomain.example.com> <v6if96$18hur$1@dont-email.me>

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Andrey Tarasevich <andreytarasevich@hotmail.com> writes:
> On 07/07/24 3:17 PM, Keith Thompson wrote:
>> I just about always use NULL, not 0, when I want a null pointer
>> constant.  Similarly, I use '\0', not 0, when I want a null character,
>> 0.0 when I want a floating-point zero, and false when I want a Boolean
>> zero.  I just like being explicit.
>
> Me too.
>
> But at the same time I realize that this is a habit forced upon my by
> circumstances, by necessity. C (as well as C++) at its beginning (and
> when I started to use the language) was not very well-suited for
> type-agnostic/DRY programming. It had a few odd features/idioms
> acknowledging the possibility, but by large both languages were
> predominantly type-aware or type-explicit. I reckon, this is actually
> what made you to "like" such explicitness. But it is pointless to talk
> about "liking" something, when one really had no choice.
>
> The moment C++ realized the full power of generic/template
> programming, it immediately rushed head-over-heels into type-agnostic
> programming style. It was `auto` and `decltype` initially, which then
> just opened the proverbial floodgates, triggering the avalanche of
> additional features targeted at the type-agnostic programming
> style. Many in C++ world still protest it, claiming that old-style
> type-explicit code is "easier to read", but they are nothing more than
> overgrown kids being reluctant to take the training wheels off their
> bikes (since they make it "easier to ride"). There no doubt anymore
> than type-agnostic programming is the next big thing for C++.
>
> The same goes for C. C is not C++, of course, but with the
> introduction of `typeof` in C23 and, hopefully, better `_Generic`
> appearing one of these days, one can hope that being type-explicit is
> a thing of the past in C as well.
>
> So, no. While I too prefer to use `NULL` for pointers and '\0' for
> character constants, I realize that do it out of deep-seated habit, or
> for nostalgic/luddite reasons mostly. Plain undecorated `0` as a
> universal type-agnostic constant should really be my choice everywhere
> today.

Hmm.  I like the idea of a type-agnostic way to express a "zero" value,
especially in a language that lets you write type-generic code.  But I
don't think I like using 0 for that purpose, since 0 is *also* a
constant of the specific type int.  C's use of 0 for all scalar types
strikes me more as an historical accident than a design feature.

And of course not all code needs to be type-agnostic.

In C++, {} seems to be an expression that gives you the default value of
any type (there are probably off-topic subtleties I'm missing).  In C23,
it can be used as an initializer ({0} works in C17 and earlier), but
not as an expression.

-- 
Keith Thompson (The_Other_Keith) Keith.S.Thompson+u@gmail.com
void Void(void) { Void(); } /* The recursive call of the void */

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question about nullptr Thiago Adams <thiago.adams@gmail.com> - 2024-07-06 08:49 -0300
  Re: question about nullptr Bonita Montero <Bonita.Montero@gmail.com> - 2024-07-06 14:13 +0200
  Re: question about nullptr John McCue <jmccue@neutron.jmcunx.com> - 2024-07-06 12:33 +0000
  Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-06 12:54 +0000
    Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-06 15:07 +0200
      Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-06 14:04 +0000
        Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-06 16:42 +0200
          Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-06 16:45 +0200
        Re: question about nullptr Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-07-06 10:50 -0700
          Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-06 23:04 +0000
            Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-06 20:06 -0700
        Re: question about nullptr bart <bc@freeuk.com> - 2024-07-06 19:20 +0100
          Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-06 23:09 +0000
          Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-06 16:31 -0700
        Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-06 13:23 -0700
          Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-06 13:28 -0700
            Re: question about nullptr Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-07 08:01 +0000
              Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-08 22:08 -0700
          Re: question about nullptr Richard Damon <richard@damon-family.org> - 2024-07-06 17:04 -0400
            Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-06 23:10 +0000
          Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-06 23:03 +0000
          Re: question about nullptr James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-06 21:44 -0400
            Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-06 19:29 -0700
              Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-07 12:53 -0700
          Re: question about nullptr Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-07 08:03 +0000
        Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-06 23:14 +0100
          Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-06 23:13 +0000
            Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-06 20:10 -0700
            Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-07 08:46 +0000
            Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-07 19:59 +0100
              Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-07 19:40 +0000
                Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-07 15:17 -0700
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-08 20:11 +0200
                Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-08 13:32 -0700
                Re: question about nullptr Michael S <already5chosen@yahoo.com> - 2024-07-08 22:28 +0300
                Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-08 15:23 -0700
                Re: question about nullptr Michael S <already5chosen@yahoo.com> - 2024-07-09 10:48 +0300
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-09 04:32 -0700
                Re: question about nullptr Thiago Adams <thiago.adams@gmail.com> - 2024-07-09 09:10 -0300
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-09 07:52 -0700
                Re: question about nullptr Thiago Adams <thiago.adams@gmail.com> - 2024-07-09 13:16 -0300
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-09 14:22 -0700
                Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-09 22:25 +0000
                Re: question about nullptr Thiago Adams <thiago.adams@gmail.com> - 2024-07-10 08:50 -0300
                Re: question about nullptr Michael S <already5chosen@yahoo.com> - 2024-07-09 15:50 +0300
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-09 07:50 -0700
                Re: question about nullptr David Brown <david.brown@hesbynett.no> - 2024-07-09 18:19 +0200
                Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-09 02:49 +0000
                Re: question about nullptr Michael S <already5chosen@yahoo.com> - 2024-07-09 11:00 +0300
                Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-09 08:21 +0000
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-09 03:57 -0700
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-08 20:17 -0700
                Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-08 21:01 -0700
                Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-08 22:06 -0700
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-10 07:51 -0700
                Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-10 14:23 -0700
                Re: question about nullptr James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-10 18:50 -0400
                Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-08 14:09 +0000
                Re: question about nullptr Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-07-08 21:45 -0700
                Re: question about nullptr Andrey Tarasevich <andreytarasevich@hotmail.com> - 2024-07-08 21:49 -0700
                Re: question about nullptr Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-11 02:42 +0000
                Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-08 22:58 -0700
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-10 07:36 -0700
                Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-10 14:15 -0700
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-08 20:07 +0200
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-08 23:55 +0100
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-10 17:28 +0200
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-11 00:25 +0100
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-12 14:08 +0200
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-13 00:59 +0100
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-13 04:01 +0200
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-15 00:00 +0100
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-13 04:18 +0200
                Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-17 09:26 -0700
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-08 12:29 +0200
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-08 17:23 +0100
                Re: question about nullptr James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-08 11:03 -0400
                Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-09 02:45 +0000
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-08 11:08 +0200
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-08 11:18 +0100
                Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-09 02:32 +0000
                Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-08 22:02 -0700
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-09 10:21 +0100
                Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-10 17:32 -0700
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-11 02:12 +0100
                Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-10 18:41 -0700
                Re: question about nullptr Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-11 02:38 +0000
                Re: question about nullptr Janis Papanagnou <janis_papanagnou+ng@hotmail.com> - 2024-07-12 14:11 +0200
                Re: question about nullptr Richard Damon <richard@damon-family.org> - 2024-07-08 07:18 -0400
                Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-08 07:19 +0000
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-08 00:42 +0100
          Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-06 20:36 -0700
      Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-06 22:11 +0000
    Re: question about nullptr bart <bc@freeuk.com> - 2024-07-06 14:51 +0100
      Re: question about nullptr Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-07 04:55 +0000
        Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-07 00:04 -0700
        Re: question about nullptr bart <bc@freeuk.com> - 2024-07-07 18:40 +0100
    Re: question about nullptr Richard Harnden <richard.nospam@gmail.invalid> - 2024-07-12 14:19 +0100
      Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-12 21:52 +0000
        Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-12 22:27 +0000
          Re: question about nullptr Kaz Kylheku <643-408-1753@kylheku.com> - 2024-07-12 23:28 +0000
            Re: question about nullptr scott@slp53.sl.home (Scott Lurndal) - 2024-07-13 00:10 +0000
              Re: question about nullptr James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-12 20:28 -0400
              Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-12 17:30 -0700
      Re: question about nullptr Tim Rentsch <tr.17687@z991.linuxsc.com> - 2024-07-13 17:21 -0700
      Re: question about nullptr Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-15 22:51 +0000
        Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-15 16:32 -0700
        Re: question about nullptr James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-15 19:49 -0400
          Re: question about nullptr Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2024-07-15 18:22 -0700
  Re: question about nullptr Richard Damon <richard@damon-family.org> - 2024-07-06 10:39 -0400
    Re: question about nullptr David Brown <david.brown@hesbynett.no> - 2024-07-06 18:57 +0200
      Re: question about nullptr Lawrence D'Oliveiro <ldo@nz.invalid> - 2024-07-07 08:00 +0000
        Re: question about nullptr David Brown <david.brown@hesbynett.no> - 2024-07-07 12:07 +0200
      Re: question about nullptr Thiago Adams <thiago.adams@gmail.com> - 2024-07-07 08:40 -0300
      Re: question about nullptr Richard Harnden <richard.nospam@gmail.invalid> - 2024-07-09 06:42 +0100
        Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-08 23:17 -0700
          Re: question about nullptr Richard Harnden <richard.nospam@gmail.invalid> - 2024-07-09 08:02 +0100
            Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-09 00:12 -0700
              Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-09 11:14 +0100
                Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-09 13:24 -0700
                Re: question about nullptr "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2024-07-09 13:28 -0700
                Re: question about nullptr Ben Bacarisse <ben@bsb.me.uk> - 2024-07-10 14:27 +0100
                Re: question about nullptr James Kuyper <jameskuyper@alumni.caltech.edu> - 2024-07-10 11:09 -0400

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