Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > comp.lang.c > #152606

Re: Two different Results between C and C++

From Keith Thompson <Keith.S.Thompson+u@gmail.com>
Newsgroups comp.lang.c
Subject Re: Two different Results between C and C++
Date 2020-06-02 11:51 -0700
Organization None to speak of
Message-ID <87ftbdwbat.fsf@nosuchdomain.example.com> (permalink)
References <rb5mq9$okv$1@gioia.aioe.org> <4ccefcca-1bde-44f7-a7b7-694476dacc64@googlegroups.com> <87k10pwi1c.fsf@nosuchdomain.example.com> <rb5vf7$rt0$1@dont-email.me>

Show all headers | View raw


Lew Pitcher <lew.pitcher@digitalfreehold.ca> writes:
> On June 2, 2020 12:26, Keith Thompson wrote:
>> mark.bluemel@gmail.com writes:
>> [...]
>>> (1!=1) is a C boolean value, which is an int.
>> 
>> Not exactly.  C does have a boolean type, called _Bool (or bool if
>> you've included <stdbool.h>.  But equality and comparison operators
>> yield values of type int, not of type bool.
>
> I believe that Mark was trying to indicate the distinction between how C++ 
> interprets (1!=1) and how C interprets it.
>
> In the C++ case, (1!=1) results in a boolean type, holding a boolean value 
> (or so Mark implies; I don't know C++)
>
> In the C case, (1~=1) results in an int type (which Mark does point out), 
> holding value that indicates the truth or falsehood of the assertion (a 
> "boolean" value).
>
> Perhaps Mark will clarify his post for us.

Yes, what Mark said is mostly correct.  My quibble is about the
phrase "C boolean value".  I suppose you could say that 0 (of type
int) is a "C boolean value", but it would make more sense to apply
that term to a value of the C type _Bool.

In C90, where _Bool didn't yet exist, I wouldn't have much of a
problem referring to 0 as a "C boolean value".

And just to add to the frivolity, the macros "false" and "true"
in <stdbool.h> expand to 0 and 1, respectively, which are of type
_Bool, not int.

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

Back to comp.lang.c | Previous | NextPrevious in thread | Next in thread | Find similar


Thread

Two different Results between C and C++ Real Troll <real.troll@trolls.com> - 2020-06-02 04:08 -1000
  Re: Two different Results between C and C++ mark.bluemel@gmail.com - 2020-06-02 07:59 -0700
    Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-02 09:26 -0700
      Re: Two different Results between C and C++ Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-06-02 12:41 -0400
        Re: Two different Results between C and C++ Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-06-02 18:09 +0100
        Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-02 11:51 -0700
          Re: Two different Results between C and C++ Ben Bacarisse <ben.usenet@bsb.me.uk> - 2020-06-02 20:44 +0100
            Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-02 12:59 -0700
        Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-02 16:06 -0400
          Re: Two different Results between C and C++ mark.bluemel@gmail.com - 2020-06-03 00:27 -0700
  Re: Two different Results between C and C++ John Bode <jfbode1029@gmail.com> - 2020-06-02 08:41 -0700
    Re: Two different Results between C and C++ Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-06-02 09:20 -0700
    Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-02 12:36 -0400
      Re: Two different Results between C and C++ John Bode <jfbode1029@gmail.com> - 2020-06-02 11:39 -0700
        Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-02 12:06 -0700
          Re: Two different Results between C and C++ Richard Damon <Richard@Damon-Family.org> - 2020-06-02 15:41 -0400
            Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-02 13:50 -0700
          Re: Two different Results between C and C++ John Bode <jfbode1029@gmail.com> - 2020-06-04 13:16 -0700
            Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-04 16:41 -0400
            Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-04 16:04 -0700
          Re: Two different Results between C and C++ raltbos@xs4all.nl (Richard Bos) - 2020-06-04 20:47 +0000
            Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-04 17:35 -0400
              Re: Two different Results between C and C++ raltbos@xs4all.nl (Richard Bos) - 2020-06-04 22:01 +0000
                Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-04 20:11 -0400
            Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-04 16:10 -0700
              Re: Two different Results between C and C++ Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2020-06-05 02:26 -0700
                Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-05 11:33 -0700
              Re: Two different Results between C and C++ Jorgen Grahn <grahn+nntp@snipabacken.se> - 2020-06-05 11:28 +0000
          Re: Two different Results between C and C++ Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-06-21 00:53 -0700
            Re: Two different Results between C and C++ Öö Tiib <ootiib@hot.ee> - 2020-06-21 03:57 -0700
            Re: Two different Results between C and C++ Richard Damon <Richard@Damon-Family.org> - 2020-06-21 08:08 -0400
              Re: Two different Results between C and C++ Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-06-28 04:59 -0700
            Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-21 10:59 -0700
            Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-21 11:40 -0700
              Re: Two different Results between C and C++ Richard Damon <Richard@Damon-Family.org> - 2020-06-21 19:50 -0400
              Re: Two different Results between C and C++ raltbos@xs4all.nl (Richard Bos) - 2020-06-29 16:20 +0000
                Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-29 11:18 -0700
                Re: Two different Results between C and C++ raltbos@xs4all.nl (Richard Bos) - 2020-06-29 21:46 +0000
                Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-29 14:59 -0700
                Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-29 18:53 -0400
                Re: Two different Results between C and C++ Sjouke Burry <burrynulnulfour@ppllaanneett.nnll> - 2020-06-30 01:40 +0200
                Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-29 17:48 -0700
                Re: Two different Results between C and C++ David Brown <david.brown@hesbynett.no> - 2020-06-30 07:45 +0200
                Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-30 15:11 -0400
                Re: Two different Results between C and C++ Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2020-06-29 17:45 -0700
        Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-02 15:51 -0400
          Re: Two different Results between C and C++ Tim Rentsch <tr.17687@z991.linuxsc.com> - 2020-06-21 01:25 -0700
            Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-21 10:34 -0700
  Re: Two different Results between C and C++ Juha Nieminen <nospam@thanks.invalid> - 2020-06-02 18:45 +0000
    Re: Two different Results between C and C++ Bart <bc@freeuk.com> - 2020-06-02 19:55 +0100
      Re: Two different Results between C and C++ Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-06-02 15:11 -0400
        Re: Two different Results between C and C++ Melzzzzz <Melzzzzz@zzzzz.com> - 2020-06-02 20:14 +0000
          Re: Two different Results between C and C++ Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-06-02 16:19 -0400
    Re: Two different Results between C and C++ Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2020-06-02 15:06 -0400
    Re: Two different Results between C and C++ James Kuyper <jameskuyper@alumni.caltech.edu> - 2020-06-02 16:20 -0400
  Re: Two different Results between C and C++ Pavel <pauldontspamtolk@removeyourself.dontspam.yahoo> - 2020-06-06 00:07 -0400

csiph-web