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

Groups > comp.lang.c > #162768

Re: C23 (C2x) changes

From David Brown <david.brown@hesbynett.no>
Newsgroups comp.lang.c
Subject Re: C23 (C2x) changes
Date 2021-09-20 09:35 +0200
Organization A noiseless patient Spider
Message-ID <si9dkd$sfs$1@dont-email.me> (permalink)
References <si99fr$ma4$1@dont-email.me>

Show all headers | View raw

On 20/09/2021 08:24, Mehdi Amini wrote:
> Hi,
> 
> It seems these are some of changes for C23(C2x) standard taken from
> draft documents:
> 
> https://en.cppreference.com/w/c/23
> https://thephd.dev/c-the-improvements-june-september-virtual-c-meeting
> 
> What do you think of changes ?
> 
> One minor suggestion for me is to have format specifier for bool type in
> printf function. Even though currently the fix is a trivial one.

I like the binary literals and digit separators (apostrophes were the
best option available for C++, and consistency with C++ is IMHO more
important than, say, using underscores would be).  Printf formatting
characters for binary are a nice idea, but they will be a bit limited if
there is no support for digit separators in the output.  And if we can
write "%w32u" in printf instead of using the PRIu32 macro, then that
will be a noticeable improvement.

The "thephd.dev" page makes the usual mistake of thinking that defined
and guaranteed incorrect results for integer overflow are better than
undefined behaviour that can be found using debugging aids, but it's
nice to see gcc's __builtin_overflow functions get standardised so that
code can be made more portable.

I don't see _BitInt(n) being nearly as big a change to embedded
development as the webpage author suggests.  Part of that is the
conservatism common in embedded development - people are still writing
/new/ code to C90 standard.  The other is that integral promotions are
not as difficult to understand as he makes out (though I personally
would be happier without them in most situations).

It's nice to see old-style function declarations /finally/ being
removed.  That will turn a lot of bad source code into compile-time
broken code, instead of bad binaries.  And there are a number of small
improvements.

All in all, I will be happy to switch to C23.  There are plenty of
things there that I have no interest in (but presumably others want),
and nothing game-changing, but some things that are a little nicer, and
that's good.

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

Thread

C23 (C2x) changes Mehdi Amini <atorrses@gmail.com> - 2021-09-20 10:54 +0430
  Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-20 09:35 +0200
    Re: C23 (C2x) changes Mehdi Amini <atorrses@gmail.com> - 2021-09-21 11:01 +0430
  Re: C23 (C2x) changes John Bode <jfbode1029@gmail.com> - 2021-09-20 10:41 -0500
    Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-20 18:17 +0200
      Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-20 18:55 +0100
        Re: C23 (C2x) changes scott@slp53.sl.home (Scott Lurndal) - 2021-09-20 18:21 +0000
        Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-20 21:39 +0200
          Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-20 21:07 +0100
            Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-20 22:59 +0200
              Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-20 22:29 +0100
                Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-20 17:43 -0700
                Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-21 17:56 +0200
                Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-21 18:05 +0100
                Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-21 11:42 -0700
                Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-22 11:37 +0200
                Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-22 11:55 +0100
                Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-22 14:21 +0200
                Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-22 13:58 +0100
                Re: C23 (C2x) changes Ian Pilcher <arequipeno@gmail.com> - 2021-09-22 12:02 -0500
                Re: C23 (C2x) changes scott@slp53.sl.home (Scott Lurndal) - 2021-09-22 17:19 +0000
          Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-20 23:05 +0100
            Re: C23 (C2x) changes scott@slp53.sl.home (Scott Lurndal) - 2021-09-20 22:47 +0000
              Re: C23 (C2x) changes Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-09-20 22:58 +0000
              Re: C23 (C2x) changes Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-02 07:16 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-02 15:15 +0000
            Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-20 17:45 -0700
        Re: C23 (C2x) changes Manfred <noname@add.invalid> - 2021-09-27 17:15 +0200
          Re: C23 (C2x) changes Ben Bacarisse <ben.usenet@bsb.me.uk> - 2021-09-27 17:38 +0100
            Re: C23 (C2x) changes Manfred <noname@add.invalid> - 2021-09-27 23:18 +0200
              Re: C23 (C2x) changes antispam@math.uni.wroc.pl - 2021-09-28 13:53 +0000
              Re: C23 (C2x) changes Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-02 08:07 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-02 15:18 +0000
                Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-02 15:04 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-03 01:58 +0000
                Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-02 22:06 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-03 10:43 +0000
                Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-03 13:30 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 05:04 +0000
                Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-03 23:24 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 06:54 +0000
                Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-10-04 09:58 +0200
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 15:52 +0000
                Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-04 10:45 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-04 20:30 +0000
                Re: C23 (C2x) changes Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-06 03:57 -0700
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-06 12:27 +0000
          Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-29 03:38 +0000
      Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-10-15 11:35 +0100
        Re: C23 (C2x) changes Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-10-15 18:27 +0000
          Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-10-15 20:08 +0100
          Re: C23 (C2x) changes Lew Pitcher <lew.pitcher@digitalfreehold.ca> - 2021-10-15 19:20 +0000
            Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-10-15 21:50 +0100
    Re: C23 (C2x) changes Florian Weimer <fw@deneb.enyo.de> - 2021-10-03 09:43 +0200
      Re: C23 (C2x) changes Guillaume <message@bottle.org> - 2021-10-03 18:53 +0200
      Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-10-03 13:55 -0700
  Re: C23 (C2x) changes William Ahern <william@25thandClement.com> - 2021-09-21 22:57 -0700
    Re: C23 (C2x) changes Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-02 08:55 -0700
      Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-02 16:36 +0000
  Re: C23 (C2x) changes Guillaume <message@bottle.org> - 2021-09-22 20:27 +0200
    Re: C23 (C2x) changes Philipp Klaus Krause <pkk@spth.de> - 2021-09-22 22:25 +0200
      Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-22 14:05 -0700
        Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-09-22 23:24 +0100
          Re: C23 (C2x) changes Thiago Adams <thiago.adams@gmail.com> - 2021-09-22 18:49 -0700
        Re: C23 (C2x) changes Guillaume <message@bottle.org> - 2021-09-23 18:47 +0200
  Static bounds checking (was Re: C23 (C2x) changes) William Ahern <william@25thandClement.com> - 2021-09-23 21:11 -0700
    Re: Static bounds checking (was Re: C23 (C2x) changes) David Brown <david.brown@hesbynett.no> - 2021-09-24 08:51 +0200
      Re: Static bounds checking (was Re: C23 (C2x) changes) Philipp Klaus Krause <pkk@spth.de> - 2021-09-24 09:30 +0200
    Re: Static bounds checking (was Re: C23 (C2x) changes) Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-24 07:52 +0000
      Re: Static bounds checking (was Re: C23 (C2x) changes) Philipp Klaus Krause <pkk@spth.de> - 2021-09-24 12:32 +0200
        Re: Static bounds checking (was Re: C23 (C2x) changes) Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-24 10:49 +0000
          Re: Static bounds checking (was Re: C23 (C2x) changes) Philipp Klaus Krause <pkk@spth.de> - 2021-09-24 14:46 +0200
      Re: Static bounds checking (was Re: C23 (C2x) changes) Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-24 18:14 +0200
        Re: Static bounds checking (was Re: C23 (C2x) changes) Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 01:00 +0000
          Re: Static bounds checking (was Re: C23 (C2x) changes) Philipp Klaus Krause <pkk@spth.de> - 2021-09-25 07:44 +0200
            Re: Static bounds checking (was Re: C23 (C2x) changes) Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 11:28 +0000
            Re: Static bounds checking (was Re: C23 (C2x) changes) antispam@math.uni.wroc.pl - 2021-09-28 10:56 +0000
          Re: Static bounds checking (was Re: C23 (C2x) changes) Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-25 09:48 +0200
            Re: Static bounds checking (was Re: C23 (C2x) changes) Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-25 11:30 +0000
              Re: Static bounds checking (was Re: C23 (C2x) changes) Kaz Kylheku <480-992-1380@kylheku.com> - 2021-09-25 20:49 +0000
                Re: Static bounds checking (was Re: C23 (C2x) changes) Branimir Maksimovic <branimir.maksimovic@gmail.com> - 2021-09-26 00:04 +0000
              Re: Static bounds checking (was Re: C23 (C2x) changes) Bonita Montero <Bonita.Montero@gmail.com> - 2021-09-26 06:56 +0200
  Re: C23 (C2x) changes Thiago Adams <thiago.adams@gmail.com> - 2021-09-27 10:15 -0700
    Re: C23 (C2x) changes Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-09-27 11:15 -0700
      Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-09-27 22:11 +0200
      Re: C23 (C2x) changes Thiago Adams <thiago.adams@gmail.com> - 2021-09-27 14:20 -0700
        Re: C23 (C2x) changes Thiago Adams <thiago.adams@gmail.com> - 2021-09-27 14:31 -0700
      Re: C23 (C2x) changes Mehdi Amini <atorrses@gmail.com> - 2021-09-28 10:43 +0330
  Re: C23 (C2x) changes Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-06 04:01 -0700
    Re: C23 (C2x) changes Thiago Adams <thiago.adams@gmail.com> - 2021-10-06 04:42 -0700
      Re: C23 (C2x) changes Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-29 04:04 -0700
        Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-10-29 16:34 +0200
    Re: C23 (C2x) changes Guillaume <message@bottle.org> - 2021-10-06 19:07 +0200
      Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-10-07 11:06 +0200
        Re: C23 (C2x) changes Guillaume <message@bottle.org> - 2021-10-07 19:31 +0200
          Re: C23 (C2x) changes David Brown <david.brown@hesbynett.no> - 2021-10-07 22:14 +0200
            Re: C23 (C2x) changes Thiago Adams <thiago.adams@gmail.com> - 2021-10-08 06:18 -0700
              Re: C23 (C2x) changes Thiago Adams <thiago.adams@gmail.com> - 2021-10-08 06:21 -0700
      Re: C23 (C2x) changes Tim Rentsch <tr.17687@z991.linuxsc.com> - 2021-10-29 04:01 -0700
    Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-15 12:59 +0200
      Re: C23 (C2x) changes Jim Jackson <jj@franjam.org.uk> - 2021-10-15 16:50 +0000
        Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-16 07:51 +0200
          Re: C23 (C2x) changes "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-10-16 11:50 -0700
            Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-16 21:28 +0200
              Re: C23 (C2x) changes Jim Jackson <jj@franjam.org.uk> - 2021-10-17 17:18 +0000
                Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-17 20:00 +0200
                Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-10-17 19:17 +0100
                Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-18 06:49 +0200
                Re: C23 (C2x) changes Bart <bc@freeuk.com> - 2021-10-18 11:23 +0100
                Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-18 14:09 +0200
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-21 01:07 +0000
                Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-21 01:02 +0000
          Re: C23 (C2x) changes Guillaume <message@bottle.org> - 2021-10-16 21:28 +0200
            Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-17 06:04 +0200
              Re: C23 (C2x) changes Manfred <noname@add.invalid> - 2021-10-17 19:35 +0200
                Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-17 20:01 +0200
                Re: C23 (C2x) changes "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2021-10-17 14:15 -0700
              Re: C23 (C2x) changes Branimir Maksimovic <branimir.maksimovic@icloud.com> - 2021-10-21 01:02 +0000
                Re: C23 (C2x) changes Bonita Montero <Bonita.Montero@gmail.com> - 2021-10-21 13:15 +0200

csiph-web