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Re: C23 (C2x) changes

From Tim Rentsch <tr.17687@z991.linuxsc.com>
Newsgroups comp.lang.c
Subject Re: C23 (C2x) changes
Date 2021-10-02 08:07 -0700
Organization A noiseless patient Spider
Message-ID <86lf3bsbwz.fsf@linuxsc.com> (permalink)
References (2 earlier) <siac7m$8r0$1@dont-email.me> <siahul$tb8$1@dont-email.me> <sisn5m$ni6$1@gioia.aioe.org> <87y27it1mo.fsf@bsb.me.uk> <sitcfp$1fgs$1@gioia.aioe.org>

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Manfred <noname@add.invalid> writes:

> [...]

> - How common is the need to model math that is strictly about
> natural numbers compared to the need for integer math?  (this is
> not a rhetorical question, I'm genuinely curious).

Combinatorics and number theory routinely concern themselves with
domains limited to the non-negative integers.  The celebrated
prime number theorem, for example, counts primes less than a
given upper bound, but considers only non-negative numbers as
primes.  Is -3 a prime?  In a sense yes, but it's easier just to
avoid the question by admitting only non-negative integers as
candidates.

> It could also be argued that after all natural numbers can be
> handled using signed integers, as long as in the transition from
> theoretical analysis to practical analysis, the limitation of
> (2^31-1) is not that different from the limitation of (2^32-1)

Considering practical aspects of writing code, if the domain of
interest is confined to non-negative values, using an unsigned
type (for function parameters, etc) makes for an easier fit, as
otherwise input values would have to be tested for being negative,
and something done to handle the offending situation.  If unsigned
types are used the problem doesn't come up.

Also, when working in code related to those theoretical domains,
I can say from first hand experience that we _always_ want that
last bit, no matter how wide the data type in question.  An extra
bit means a larger range of applicability, and that's always
useful.

> - more relevant, IMO: the main difference between signed and
> unsigned types is that in the latter case all bits are digits,
> i.e. they constitute a homogeneous set, which makes them
> specifically useful for binary arithmetic (which justifies the
> difference in semantics, in my view).

Speaking for myself a more important difference is that signed
types have various pesky undefined and implementation-defined
behaviors, whereas unsigned types do not.  In most cases it's
easier to reason about code that uses unsigned types if the range
of possible values is even remotely close to the limits of the
type in question.  I routinely use unsigned types for variables
unless the variable in question must be able to hold a negative
value.

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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

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