Re: Constexpr evaluation of heavy stuff

From	Paavo Helde <eesnimi@osa.pri.ee>
Newsgroups	comp.lang.c++
Subject	Re: Constexpr evaluation of heavy stuff
Date	2022-05-19 20:32 +0300
Organization	A noiseless patient Spider
Message-ID	<t65v09$bd9$1@dont-email.me> (permalink)
References	(1 earlier) <t64r23$ncc$1@dont-email.me> <t654dl$cek$1@dont-email.me> <t656ke$otk$1@dont-email.me> <t65ed3$jgh$1@dont-email.me> <b4c80897-17a3-4951-a4a5-f3ca95c2f5d5n@googlegroups.com>

Show all headers | View raw

19.05.2022 16:19 Malcolm McLean kirjutas:
> Most integers are inherently non-negative, usually because they count things
> or index things. So it's natural when using a language that allows both
> signed and unsigned types to think that "unsigned" is designed to cover
> this type of usage. Nothing "religious" about it.

Yes, that would be fine if the language provided such an unsigned type. 
Alas, in C and C++ there are no such unsigned arithmetic types. All we 
have got are some strange cyclic wrapover types, and the wrapover 
threshold is not even fixed (unsigned int can be 16 bits, 32 bits or 
more). There are very few numeric algorithms requiring such wrap-over types.

Why is this important? For signed ints wrap-over is UB, so if wrap-over 
happens one knows there is something wrong; one can also instrument the 
compiler to detect and report such bugs. Nothing like that can be done 
for unsigned types.

Thread

Constexpr evaluation of heavy stuff Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-18 16:17 -0700
  Re: Constexpr evaluation of heavy stuff "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-19 09:19 +0200
    Re: Constexpr evaluation of heavy stuff David Brown <david.brown@hesbynett.no> - 2022-05-19 11:59 +0200
      Re: Constexpr evaluation of heavy stuff "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-19 12:37 +0200
        Re: Constexpr evaluation of heavy stuff David Brown <david.brown@hesbynett.no> - 2022-05-19 14:49 +0200
          Re: Constexpr evaluation of heavy stuff Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-19 06:19 -0700
            Re: Constexpr evaluation of heavy stuff Paavo Helde <eesnimi@osa.pri.ee> - 2022-05-19 20:32 +0300
              Re: Constexpr evaluation of heavy stuff Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-20 01:12 -0700
                Re: Constexpr evaluation of heavy stuff Juha Nieminen <nospam@thanks.invalid> - 2022-05-20 08:37 +0000
                Re: Constexpr evaluation of heavy stuff Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-20 02:21 -0700
                Re: Constexpr evaluation of heavy stuff Ben <ben.usenet@bsb.me.uk> - 2022-05-20 11:25 +0100
                Re: Constexpr evaluation of heavy stuff David Brown <david.brown@hesbynett.no> - 2022-05-20 12:47 +0200
                Re: Constexpr evaluation of heavy stuff Ben <ben.usenet@bsb.me.uk> - 2022-05-20 12:13 +0100
                Re: Constexpr evaluation of heavy stuff David Brown <david.brown@hesbynett.no> - 2022-05-20 14:27 +0200
                Re: Constexpr evaluation of heavy stuff Öö Tiib <ootiib@hot.ee> - 2022-05-20 06:33 -0700
                Re: Constexpr evaluation of heavy stuff Paavo Helde <eesnimi@osa.pri.ee> - 2022-05-20 17:15 +0300
                Re: Constexpr evaluation of heavy stuff Christian Gollwitzer <auriocus@gmx.de> - 2022-05-20 18:57 +0200
                Re: Constexpr evaluation of heavy stuff Paavo Helde <eesnimi@osa.pri.ee> - 2022-05-20 22:31 +0300
                Re: Constexpr evaluation of heavy stuff Manfred <noname@add.invalid> - 2022-05-21 21:56 +0200
                Re: Constexpr evaluation of heavy stuff Öö Tiib <ootiib@hot.ee> - 2022-05-21 23:24 -0700
                Re: Constexpr evaluation of heavy stuff Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-22 04:56 -0700
                Re: Constexpr evaluation of heavy stuff Öö Tiib <ootiib@hot.ee> - 2022-05-22 06:15 -0700
                Re: Constexpr evaluation of heavy stuff Manfred <noname@add.invalid> - 2022-05-22 21:46 +0200
                Re: Constexpr evaluation of heavy stuff "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-22 23:23 +0200
                Re: Constexpr evaluation of heavy stuff Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-22 16:26 -0700
                Re: Constexpr evaluation of heavy stuff Manfred <noname@add.invalid> - 2022-05-23 17:24 +0200
                Re: Constexpr evaluation of heavy stuff Richard Damon <Richard@Damon-Family.org> - 2022-05-23 19:41 -0400
                Re: Constexpr evaluation of heavy stuff scott@slp53.sl.home (Scott Lurndal) - 2022-05-24 16:15 +0000
                Re: Constexpr evaluation of heavy stuff Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-05-24 05:37 -0700
                Re: Constexpr evaluation of heavy stuff Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-20 04:19 -0700
                Re: Constexpr evaluation of heavy stuff Ben <ben.usenet@bsb.me.uk> - 2022-05-20 12:32 +0100
                Re: Constexpr evaluation of heavy stuff Juha Nieminen <nospam@thanks.invalid> - 2022-05-20 10:40 +0000
                Re: Constexpr evaluation of heavy stuff David Brown <david.brown@hesbynett.no> - 2022-05-20 12:31 +0200
                Re: Constexpr evaluation of heavy stuff Juha Nieminen <nospam@thanks.invalid> - 2022-05-20 10:43 +0000
                Re: Constexpr evaluation of heavy stuff David Brown <david.brown@hesbynett.no> - 2022-05-20 14:52 +0200
          Re: Constexpr evaluation of heavy stuff "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-19 15:34 +0200
    Re: Constexpr evaluation of heavy stuff "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-19 17:03 +0200
  Re: Constexpr evaluation of heavy stuff Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-05-19 08:53 -0700
    Re: Constexpr evaluation of heavy stuff Marcel Mueller <news.5.maazl@spamgourmet.org> - 2022-05-19 18:33 +0200

csiph-web