Re: Anyone ever used vector<bool> ?

From	Ben <ben.usenet@bsb.me.uk>
Newsgroups	comp.lang.c++
Subject	Re: Anyone ever used vector<bool> ?
Date	2022-05-06 11:54 +0100
Organization	A noiseless patient Spider
Message-ID	<87sfpn7wz2.fsf@bsb.me.uk> (permalink)
References	(6 earlier) <4dc0556b-577d-4779-9e92-ad70622ce178n@googlegroups.com> <875ymkp4zv.fsf@bsb.me.uk> <t5192j$kud$1@dont-email.me> <8735hnohzi.fsf@bsb.me.uk> <t52msn$64k$1@dont-email.me>

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"Alf P. Steinbach" <alf.p.steinbach@gmail.com> writes:

> On 5 May 2022 22:13, Ben wrote:
>> "Alf P. Steinbach" <alf.p.steinbach@gmail.com> writes:
>> 
>>> On 5 May 2022 13:56, Ben wrote:
>>>> Öö Tiib <ootiib@hot.ee> writes:
>>>>
>>>>> On Thursday, 5 May 2022 at 12:50:26 UTC+3, Ben wrote:
>>>>>> Juha Nieminen <nos...@thanks.invalid> writes:
>>>>>>
>>>>>>> Paavo Helde <ees...@osa.pri.ee> wrote:
>>>>>>>> I have hard time finding any use case at all for std::list.
>>>>>>>
>>>>>>> When I was working at the university here I once had to implement
>>>>>>> (a rather complicated and advanced) algorithm (which had something to
>>>>>>> do with graph manipulation) which required a doubly-linked list. No other
>>>>>>> data container would have done the job because the speed of the algorithm
>>>>>>> relied on the ability to splice linked lists (and sections of them).
>>>>>>>
>>>>>>> That being said, std::list couldn't be used for this, especially now
>>>>>>> that std::list::splice() is not an O(1) operation (which would pretty
>>>>>>> much defeat the purpose).
>>>>>>
>>>>>> It's O(1) in C++11, 14 and 20 (at least in the public drafts).
>>>>>
>>>>> It has 6 overloads. Most are O(1) but one case where we transfer iterator
>>>>> range from other list to this list is linear in length of said range.
>>>> Obviously, but that's surely not what the OP was talking about.  That
>>>> one could never have been, and will never be O(1).
>>>
>>> With the choice of potentially O(n) `.size()`, instead of the silly
>>> C++11 decision, all splicing overloads could be O(1) and `std::list`
>>> could have been useful for something.
>>>
>>> Since the word "now" was used, that was surely what was being mentioned.
>>>
>>> Obviously. ;-)
>> How much of your post does the smiley apply to?  I don't want to waste
>> everyone's time...
>
> I guess you're unfamiliar with the history. The fight was about the
> guaranteed complexity of `.size()`. With O(1) complexity a splice has
> to count the number of spliced nice, which turns a simple O(1) link
> manipulation into O(n) counting.

I'm familiar with the trade-off in abstract (since it crops up every
time one implements a list as was so common in days gone by), but I did
not know there had been a fight about it in C++.

> The academic idealists won, the practically oriented people lost, and
> `std::list` became useless.

Curious that you put it like that.  There doesn't seem to be anything
obviously idealistic in opting for O(1) size and linear splicing for
"foreign" sub-lists.  I don't recall ever wanting that form of splice,
so I would consider C++'s choice quite practical (for me).  What makes
this the "idealists" preferred option?

The engineer's perspective might be to have two list variants, one with
a maintained length and one without.  Did that option crop up in the
fight?

-- 
Ben.

Thread

Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-03 15:16 +0000
  Re: Anyone ever used vector<bool> ? Ben <ben.usenet@bsb.me.uk> - 2022-05-03 16:39 +0100
    Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-03 16:12 +0000
      Re: Anyone ever used vector<bool> ? Bo Persson <bo@bo-persson.se> - 2022-05-03 20:25 +0200
        Re: Anyone ever used vector<bool> ? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2022-05-03 12:00 -0700
        Re: Anyone ever used vector<bool> ? Juha Nieminen <nospam@thanks.invalid> - 2022-05-04 10:50 +0000
  Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-03 16:14 +0000
  Re: Anyone ever used vector<bool> ? Jack Lemmon <invalid@invalid.net> - 2022-05-03 17:33 +0100
    Re: Anyone ever used vector<bool> ? Manfred <noname@add.invalid> - 2022-05-03 19:13 +0200
      Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-04 09:13 +0000
    Re: Anyone ever used vector<bool> ? Juha Nieminen <nospam@thanks.invalid> - 2022-05-04 10:45 +0000
      Re: Anyone ever used vector<bool> ? Paavo Helde <eesnimi@osa.pri.ee> - 2022-05-04 14:09 +0300
        Re: Anyone ever used vector<bool> ? Frederick Virchanza Gotham <cauldwell.thomas@gmail.com> - 2022-05-04 14:39 -0700
          Re: Anyone ever used vector<bool> ? red floyd <no.spam.here@its.invalid> - 2022-05-04 15:17 -0700
            Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-05 01:57 -0400
          Re: Anyone ever used vector<bool> ? Paavo Helde <eesnimi@osa.pri.ee> - 2022-05-05 09:12 +0300
        Re: Anyone ever used vector<bool> ? Juha Nieminen <nospam@thanks.invalid> - 2022-05-05 06:17 +0000
          Re: Anyone ever used vector<bool> ? Ben <ben.usenet@bsb.me.uk> - 2022-05-05 10:49 +0100
            Re: Anyone ever used vector<bool> ? Öö Tiib <ootiib@hot.ee> - 2022-05-05 04:29 -0700
              Re: Anyone ever used vector<bool> ? Ben <ben.usenet@bsb.me.uk> - 2022-05-05 12:56 +0100
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-05 21:37 +0200
                Re: Anyone ever used vector<bool> ? Ben <ben.usenet@bsb.me.uk> - 2022-05-05 21:13 +0100
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-06 10:39 +0200
                Re: Anyone ever used vector<bool> ? Ben <ben.usenet@bsb.me.uk> - 2022-05-06 11:54 +0100
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-06 14:29 +0200
                Re: Anyone ever used vector<bool> ? Ben <ben.usenet@bsb.me.uk> - 2022-05-06 17:05 +0100
                Re: Anyone ever used vector<bool> ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-06 10:22 -0700
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-06 22:18 +0200
                Re: Anyone ever used vector<bool> ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-06 13:51 -0700
                Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-07 08:41 +0000
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-07 12:33 +0200
                Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-07 16:12 +0000
                Re: Anyone ever used vector<bool> ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-07 09:37 -0700
                Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-09 09:02 +0000
                Re: Anyone ever used vector<bool> ? Bo Persson <bo@bo-persson.se> - 2022-05-09 12:14 +0200
                Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-09 15:36 +0000
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-09 11:56 -0400
                Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-09 16:18 +0000
                Re: Anyone ever used vector<bool> ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-09 09:38 -0700
                Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-10 15:55 +0000
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-10 13:28 -0400
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-10 10:16 -0400
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-10 18:40 +0200
                Re: Anyone ever used vector<bool> ? Manfred <noname@add.invalid> - 2022-05-10 19:50 +0200
                Re: Anyone ever used vector<bool> ? Öö Tiib <ootiib@hot.ee> - 2022-05-12 05:44 -0700
                Re: Anyone ever used vector<bool> ? Manfred <noname@add.invalid> - 2022-05-12 17:24 +0200
                Re: Anyone ever used vector<bool> ? Öö Tiib <ootiib@hot.ee> - 2022-05-12 20:11 -0700
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-12 12:53 -0400
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-12 22:53 -0400
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-13 18:34 +0200
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-13 23:46 -0400
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-14 11:43 +0200
                Re: Anyone ever used vector<bool> ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-05-15 07:48 -0700
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-16 03:30 +0200
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-15 22:57 -0400
                Re: Anyone ever used vector<bool> ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-05-17 05:30 -0700
                Re: Anyone ever used vector<bool> ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-05-17 05:19 -0700
                Re: Anyone ever used vector<bool> ? Juha Nieminen <nospam@thanks.invalid> - 2022-05-16 05:46 +0000
                Re: Anyone ever used vector<bool> ? Tim Rentsch <tr.17687@z991.linuxsc.com> - 2022-05-17 05:37 -0700
                Re: Anyone ever used vector<bool> ? wij <wyniijj2@gmail.com> - 2022-05-12 08:05 -0700
                Re: Anyone ever used vector<bool> ? scott@slp53.sl.home (Scott Lurndal) - 2022-05-09 17:20 +0000
                Re: Anyone ever used vector<bool> ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-09 12:05 -0700
                Re: Anyone ever used vector<bool> ? Bo Persson <bo@bo-persson.se> - 2022-05-09 21:57 +0200
                Re: Anyone ever used vector<bool> ? wij <wyniijj2@gmail.com> - 2022-05-09 13:56 -0700
                Re: Anyone ever used vector<bool> ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-09 08:33 -0700
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-09 11:56 -0400
                Re: Anyone ever used vector<bool> ? Manfred <noname@add.invalid> - 2022-05-09 18:13 +0200
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-10 10:14 -0400
                Re: Anyone ever used vector<bool> ? scott@slp53.sl.home (Scott Lurndal) - 2022-05-10 14:31 +0000
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-07 18:38 +0200
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-07 18:28 -0400
                Re: Anyone ever used vector<bool> ? Manfred <noname@add.invalid> - 2022-05-08 18:37 +0200
                Re: Anyone ever used vector<bool> ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-08 11:50 -0700
                Re: Anyone ever used vector<bool> ? James Kuyper <jameskuyper@alumni.caltech.edu> - 2022-05-08 18:18 -0400
                Re: Anyone ever used vector<bool> ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-07 09:45 -0700
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-07 19:12 +0200
                Re: Anyone ever used vector<bool> ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-07 20:36 -0700
                Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-05-08 08:26 +0200
                Re: Anyone ever used vector<bool> ? scott@slp53.sl.home (Scott Lurndal) - 2022-05-06 13:55 +0000
                Re: Anyone ever used vector<bool> ? Juha Nieminen <nospam@thanks.invalid> - 2022-05-06 06:35 +0000
                Re: Anyone ever used vector<bool> ? Ben <ben.usenet@bsb.me.uk> - 2022-05-06 11:29 +0100
                Re: Anyone ever used vector<bool> ? Juha Nieminen <nospam@thanks.invalid> - 2022-05-09 04:58 +0000
                Re: Anyone ever used vector<bool> ? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-05-08 22:30 -0700
  Re: Anyone ever used vector<bool> ? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-05-03 14:41 -0700
  Re: Anyone ever used vector<bool> ? Andrea Venturoli <ml.diespammer@netfence.it> - 2022-05-04 08:20 +0200
  Re: Anyone ever used vector<bool> ? wij wij <wyniijj2@gmail.com> - 2022-05-04 03:21 -0700
    Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-04 10:52 +0000
  Re: Anyone ever used vector<bool> ? Juha Nieminen <nospam@thanks.invalid> - 2022-05-04 10:47 +0000
    Re: Anyone ever used vector<bool> ? Muttley@dastardlyhq.com - 2022-05-04 10:53 +0000
  Re: Anyone ever used vector<bool> ? Bonita Montero <Bonita.Montero@gmail.com> - 2022-06-01 05:46 +0200
    Re: Anyone ever used vector<bool> ? Bonita Montero <Bonita.Montero@gmail.com> - 2022-06-01 07:31 +0200
    Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-06-01 14:20 +0200
      Re: Anyone ever used vector<bool> ? Bonita Montero <Bonita.Montero@gmail.com> - 2022-06-01 14:23 +0200
        Re: Anyone ever used vector<bool> ? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-06-01 14:26 +0200
          Re: Anyone ever used vector<bool> ? Bonita Montero <Bonita.Montero@gmail.com> - 2022-06-01 14:40 +0200

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