Re: CHAR_BIT is not eight

From	Muttley@dastardlyhq.com
Newsgroups	comp.lang.c++
Subject	Re: CHAR_BIT is not eight
Date	2022-10-14 14:58 +0000
Organization	Aioe.org NNTP Server
Message-ID	<tibtfd$1sps$1@gioia.aioe.org> (permalink)
References	(4 earlier) <ti9bar$1qfh$1@gioia.aioe.org> <ti9ulc$1sd84$1@dont-email.me> <20221013223034.00002f0b@reddwarf.jmc.corp> <tibo3h$24fcq$1@dont-email.me> <20221014144746.00000b28@reddwarf.jmc.corp>

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On Fri, 14 Oct 2022 14:47:46 +0100
Mr Flibble <flibble@reddwarf.jmc.corp> wrote:
>On Fri, 14 Oct 2022 15:27:13 +0200
>David Brown <david.brown@hesbynett.no> wrote:
>> Yes, it is always /possible/.  But the complications and effort
>> involved is unlikely to be worth the effort, and you'd still end up
>> with something taking a massive amount of code space.  (With
>> "massive" being relative to the small code memories of such systems.)
>> 
>> It's not uncommon in my coding to build up a few lists at the startup
>> of the system - lists of "run" functions or software timers, etc.
>> Modules might register such callbacks or functions when initialised.
>> In "big system" C++, you might just use a vector for that - adding
>> your timer objects to your vector as needed.  It's simple and easy in
>> the code.
>> 
>> But in a resource-constraint embedded system, where efficiency of
>> code space, ram space and run-time is important (though run-time
>> efficiency is usually less important for startup code), that's not
>> what you would do.  You make your timer class have the required list
>> link pointers in the class, have each registering function declare
>> their timer object with static lifetime, and your registration
>> function links them together.
>> 
>> There's no doubt that this takes a bit more effort to write than an 
>> off-the-shelf std::vector.  But it is vastly simpler than faffing
>> around making your own allocator, avoids the use of any kind of
>> dynamic memory (using neither the standard heap nor a home-made
>> allocation system), and pulls in a tiny fraction of the amount of
>> library code.
>> 
>> std::array<> is free - it's just a nice wrapper around a plain
>> C-style array.
>
>List link pointers? Again there is no reason to not use std::list with
>a suitable allocator even on such resource constrained hardware and I
>disagree that the resultant text size and ram usage would be any worse
>than anything you could come up with by hand. 

If the memory layout is hard coded at boot time why even bother pulling in 
std::list or any kind of container as you don't need their generic 
functionality which will almost certainly waste EEPROM space. With embedded 
development you often literally have to worry about every byte you use both in
ROM and RAM and whether the mainloop is going to be fast enough to do its job.

Thread

CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-12 15:57 -0700
  Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-12 16:01 -0700
  Re: CHAR_BIT is not eight Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-10-12 17:16 -0700
    Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 11:38 +0200
    Re: CHAR_BIT is not eight Michael S <already5chosen@yahoo.com> - 2022-11-16 06:24 -0800
      Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-17 11:04 +0100
        Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-11-17 16:40 +0000
          Re: CHAR_BIT is not eight Richard Damon <Richard@Damon-Family.org> - 2022-11-17 23:23 -0500
            Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-18 08:16 +0100
              Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-11-18 16:33 +0000
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-18 18:54 +0100
            Re: CHAR_BIT is not eight Michael S <already5chosen@yahoo.com> - 2022-11-18 03:47 -0800
              Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-11-18 14:52 +0000
            Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-11-18 16:32 +0000
              Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-11-18 19:05 +0100
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-11-18 18:16 +0000
  Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-13 08:02 +0000
    Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-13 08:08 +0000
      Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 11:35 +0200
        Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 02:53 -0700
          Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 11:57 +0200
            Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 03:05 -0700
            Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-17 06:18 +0000
            Re: CHAR_BIT is not eight Lynn McGuire <lynnmcguire5@gmail.com> - 2022-10-17 15:29 -0500
    Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-13 02:06 -0700
      Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 11:42 +0200
        Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-13 15:36 +0000
          Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 23:06 +0200
            Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-13 22:30 +0100
              Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-14 15:27 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-14 14:47 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-14 14:58 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-14 21:01 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 10:28 +0000
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-15 13:39 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 12:45 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:18 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:24 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:34 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:39 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:53 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:55 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-15 15:57 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 16:59 +0100
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-17 15:27 +0000
                Re: CHAR_BIT is not eight "daniel...@gmail.com" <danielaparker@gmail.com> - 2022-10-17 09:04 -0700
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-17 16:13 +0000
                Re: CHAR_BIT is not eight red floyd <no.spam.here@its.invalid> - 2022-10-17 09:44 -0700
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-17 17:47 +0100
                Re: CHAR_BIT is not eight Manfred <noname@add.invalid> - 2022-10-18 01:10 +0200
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-17 16:22 -0700
                Re: CHAR_BIT is not eight Paul N <gw7rib@aol.com> - 2022-10-18 05:13 -0700
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-18 15:04 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-18 17:40 +0100
                Re: CHAR_BIT is not eight "daniel...@gmail.com" <danielaparker@gmail.com> - 2022-10-18 12:14 -0700
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-19 15:12 +0000
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-10-19 15:35 +0000
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-20 16:16 +0000
                Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 20:13 +0200
                Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 20:11 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-15 20:03 +0100
                Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-16 07:51 +0200
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 17:03 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 16:34 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 18:51 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 18:11 +0100
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 19:18 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 22:02 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 21:19 +0100
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-10-16 21:24 +0000
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 14:38 -0700
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 14:48 -0700
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-16 22:39 +0100
                Re: CHAR_BIT is not eight scott@slp53.sl.home (Scott Lurndal) - 2022-10-16 23:49 +0000
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-17 09:54 +0200
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-17 17:31 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-17 19:56 +0200
                Re: CHAR_BIT is not eight Muttley@dastardlyhq.com - 2022-10-17 15:29 +0000
                Re: CHAR_BIT is not eight Mr Flibble <flibble@reddwarf.jmc.corp> - 2022-10-17 17:33 +0100
                Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 11:55 -0700
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-15 13:06 -0700
                Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-15 15:42 -0700
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-16 19:10 +0200
                Re: CHAR_BIT is not eight Vir Campestris <vir.campestris@invalid.invalid> - 2022-10-16 21:28 +0100
                Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-17 10:09 +0200
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 13:35 -0700
                Re: CHAR_BIT is not eight "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-10-16 13:36 -0700
      Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-11-02 17:46 -0700
    Re: CHAR_BIT is not eight Bo Persson <bo@bo-persson.se> - 2022-10-13 11:10 +0200
      Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-13 10:49 +0000
        Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-13 12:05 +0000
          Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-13 06:34 -0700
          Re: CHAR_BIT is not eight Ben Bacarisse <ben.usenet@bsb.me.uk> - 2022-10-13 15:24 +0100
        Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-13 15:59 +0200
          Re: CHAR_BIT is not eight Juha Nieminen <nospam@thanks.invalid> - 2022-10-14 05:54 +0000
            Re: CHAR_BIT is not eight Paavo Helde <eesnimi@osa.pri.ee> - 2022-10-14 09:16 +0300
              Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-11-16 05:41 -0800
                Re: CHAR_BIT is not eight Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-11-16 10:38 -0800
                Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-05 11:42 -0800
                Re: CHAR_BIT is not eight Öö Tiib <ootiib@hot.ee> - 2022-12-06 01:03 -0800
                Re: CHAR_BIT is not eight Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-12-28 20:49 -0800
            Re: CHAR_BIT is not eight Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-10-14 00:17 -0700
              Re: CHAR_BIT is not eight David Brown <david.brown@hesbynett.no> - 2022-10-14 15:33 +0200
              Re: CHAR_BIT is not eight Vir Campestris <vir.campestris@invalid.invalid> - 2022-10-16 21:37 +0100
                Re: CHAR_BIT is not eight Lynn McGuire <lynnmcguire5@gmail.com> - 2022-10-17 15:24 -0500
  Re: CHAR_BIT is not eight Bonita Montero <Bonita.Montero@gmail.com> - 2022-10-15 11:34 +0200

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