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Re: Is std::move() a misleading misnomer?

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Am 15.07.2022 um 14:02 schrieb Juha Nieminen:

> Let's take a relatively simple line of code:
> 
>      v1 = std::move(v2);
> 
> What does that do? Well, we know for certain (at least if the type of 'v1'
> and 'v2' has been logically implemented) that 'v1' will contain what
> 'v2' contained before this statement.
> 
> But what will 'v2' contain?
> 
> It depends. (More particularly, it depends on whether the type in
> question implements a move assignment operator, and it has been
> implemented in the recommended way.)
> 
> But should it really depend on anything? Isn't that statement
> expressing the desire to *move* the contents of 'v2' into 'v1',
> thus leaving 'v2' empty? (Even if under the hood a deep copy
> is being done instead, consistency of behavior would dictate
> for 'v2' to become empty nevertheless.)
> 
> The fact is that if we don't know the type of 'v1' and 'v2'
> we cannot assume that 'v2' will be empty.
> 
> Since std::move() does not guarantee that the contents will be
> moved, isn't it quite a misnomer?
> 
> std::to_rvalue() might be more cryptic, but at least it would
> express much better what it's actually doing.

That actually only does happen when v1 is a templated data type.
Otherwise you'll know whether v1 has a move assignment operator.
If it dosn't that's actually only a performance problem, but not
a semantical problem since you can expect the copy assignment
operator to make a copy.

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Is std::move() a misleading misnomer? Juha Nieminen <nospam@thanks.invalid> - 2022-07-15 12:02 +0000
  Re: Is std::move() a misleading misnomer? Bonita Montero <Bonita.Montero@gmail.com> - 2022-07-15 14:43 +0200
  Re: Is std::move() a misleading misnomer? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-15 06:18 -0700
    Re: Is std::move() a misleading misnomer? Bonita Montero <Bonita.Montero@gmail.com> - 2022-07-15 19:09 +0200
  Re: Is std::move() a misleading misnomer? Bo Persson <bo@bo-persson.se> - 2022-07-15 16:01 +0200
    Re: Is std::move() a misleading misnomer? Juha Nieminen <nospam@thanks.invalid> - 2022-07-16 18:21 +0000
      Re: Is std::move() a misleading misnomer? Bo Persson <bo@bo-persson.se> - 2022-07-16 21:11 +0200
        Re: Is std::move() a misleading misnomer? Juha Nieminen <nospam@thanks.invalid> - 2022-07-17 14:28 +0000
  Re: Is std::move() a misleading misnomer? Gawr Gura <gawrgura@mail.hololive.com> - 2022-07-15 08:34 -0700
  Re: Is std::move() a misleading misnomer? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2022-07-15 16:03 +0000
    Re: Is std::move() a misleading misnomer? Bonita Montero <Bonita.Montero@gmail.com> - 2022-07-15 19:12 +0200
      Re: Is std::move() a misleading misnomer? Jorgen Grahn <grahn+nntp@snipabacken.se> - 2022-07-16 19:24 +0000
  Re: Is std::move() a misleading misnomer? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2022-07-15 23:08 +0200
  Re: Is std::move() a misleading misnomer? Paavo Helde <eesnimi@osa.pri.ee> - 2022-07-16 11:48 +0300
  Re: Is std::move() a misleading misnomer? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-07-16 16:31 -0700
    Re: Is std::move() a misleading misnomer? Malcolm McLean <malcolm.arthur.mclean@gmail.com> - 2022-07-16 18:32 -0700
      Re: Is std::move() a misleading misnomer? "Chris M. Thomasson" <chris.m.thomasson.1@gmail.com> - 2022-07-19 16:41 -0700
  Re: Is std::move() a misleading misnomer? wij <wyniijj2@gmail.com> - 2022-07-18 16:14 -0700
    Re: Is std::move() a misleading misnomer? Bonita Montero <Bonita.Montero@gmail.com> - 2022-07-19 07:59 +0200
  Re: Is std::move() a misleading misnomer? Anthony Capobianco <kiiwy112@gmail.com> - 2022-07-20 05:11 -0700
    Re: Is std::move() a misleading misnomer? Paavo Helde <eesnimi@osa.pri.ee> - 2022-07-20 15:26 +0300
    Re: Is std::move() a misleading misnomer? Manfred <noname@add.invalid> - 2022-07-21 01:16 +0200
    Re: Is std::move() a misleading misnomer? "Fred. Zwarts" <F.Zwarts@KVI.nl> - 2022-07-21 09:47 +0200
    Re: Is std::move() a misleading misnomer? Juha Nieminen <nospam@thanks.invalid> - 2022-07-21 09:05 +0000
      Re: Is std::move() a misleading misnomer? Paavo Helde <eesnimi@osa.pri.ee> - 2022-07-21 13:12 +0300
      Re: Is std::move() a misleading misnomer? red floyd <no.spam.here@its.invalid> - 2022-07-21 13:09 -0700
  Re: Is std::move() a misleading misnomer? Andrey Tarasevich <andreytarasevich@hotmail.com> - 2022-07-20 13:08 -0700

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