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Re: NULL versus 0

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On 9/27/21 1:47 AM, Juha Nieminen wrote:
> Paavo Helde <myfirstname@osa.pri.ee> wrote:
>> In C++ (unlike C), NULL is a macro defined to 0, so there is no 
>> difference.
> 
> Actually, many standard library implementations define NULL to be
> nullptr (if we are in C++11 or newer).
> 
> (I haven't checked the standard, but this tells me that the standard does
> not mandate NULL to be defined as 0.)

The mandate is quite clear:

"The macro NULL is an implementation-defined null pointer constant."
(17.2p3).

Note that "null pointer constant" has a different definition in C++ than
in C, and when compiling using C++, NULL must have a definition that
meets C++ requirements rather than C requirements. In particular, that
means that NULL can expand to "a prvalue of type std::nullptr_t." (7.3.11p1)

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NULL versus 0 "das...@gmail.com" <dashley@gmail.com> - 2021-09-25 11:03 -0700
  Re: NULL versus 0 Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 18:16 +0000
  Re: NULL versus 0 Paavo Helde <myfirstname@osa.pri.ee> - 2021-09-25 21:20 +0300
    Re: NULL versus 0 Paavo Helde <myfirstname@osa.pri.ee> - 2021-09-25 21:32 +0300
      Re: NULL versus 0 "das...@gmail.com" <dashley@gmail.com> - 2021-09-25 12:08 -0700
    Re: NULL versus 0 Juha Nieminen <nospam@thanks.invalid> - 2021-09-27 05:47 +0000
      Re: NULL versus 0 Bo Persson <bo@bo-persson.se> - 2021-09-27 08:32 +0200
        Re: NULL versus 0 "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-26 23:37 -0700
        Re: NULL versus 0 "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-09-27 10:32 +0200
          Re: NULL versus 0 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-27 11:32 -0700
      Re: NULL versus 0 James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-27 15:03 -0400
  Re: NULL versus 0 "see.my....@gmail.com" <see.my.homepage@gmail.com> - 2021-09-25 13:05 -0700
    Re: NULL versus 0 Jorgen Grahn <grahn+nntp@snipabacken.se> - 2021-09-26 06:58 +0000
      Re: NULL versus 0 Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-26 07:47 +0000
        Re: NULL versus 0 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-26 02:15 -0700
          Re: NULL versus 0 Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-26 09:38 +0000
            Re: NULL versus 0 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-26 15:03 -0700
              Re: NULL versus 0 Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-29 02:29 +0000
                Re: NULL versus 0 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-28 20:34 -0700
                Re: NULL versus 0 David Brown <david.brown@hesbynett.no> - 2021-09-29 08:52 +0200
        Re: NULL versus 0 Bo Persson <bo@bo-persson.se> - 2021-09-26 13:54 +0200
          Re: NULL versus 0 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-26 15:17 -0700
          Re: NULL versus 0 Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-29 02:26 +0000
      Re: NULL versus 0 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-26 02:17 -0700
      Re: NULL versus 0 HorseyWorsey@the_stables.com - 2021-09-26 14:20 +0000
  Re: NULL versus 0 James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-09-25 17:36 -0400
  Re: NULL versus 0 "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-09-26 23:05 -0700

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