Re: How to write wide char string literals?

From	"Alf P. Steinbach" <alf.p.steinbach@gmail.com>
Newsgroups	comp.lang.c++
Subject	Re: How to write wide char string literals?
Date	2021-07-02 15:37 +0200
Organization	A noiseless patient Spider
Message-ID	<sbn4qd$1cs$1@dont-email.me> (permalink)
References	(3 earlier) <YJYCI.5782$5J1.4863@fx08.iad> <sbjh2o$1bq6$1@gioia.aioe.org> <sbkl6u$cd5$1@dont-email.me> <sbm82o$1rhp$1@gioia.aioe.org> <sbm94h$fif$1@dont-email.me>

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On 2 Jul 2021 07:44, James Kuyper wrote:
> On 7/2/21 1:26 AM, Juha Nieminen wrote:
>> James Kuyper <jameskuyper@alumni.caltech.edu> wrote:
>>> Why would you use wchar_t if you char about unicode? You should be using
>>> string literal using either the u8, u, or U prefixes, and store/access
>>> the strings as arrays of char, char16_t, or char32_t, respectively. Such
>>> literals are guaranteed to be in UTF-8, UTF-16, or UTF-32 encoding,
>>> respectively.
>>
>> No my choice in this case.
> 
> Recent messages reminded me of Window's strong incentives to use
> wchar_t, something I've thankfully had no experience with. As a result,
> what I'm about to say may be incorrect - but it seems to me that a
> conforming implementation of C++ targeting Windows should have wchar_t
> be the same as char16_t, so you should be able to freely use u prefixed
> string literals and char16_t with code that needs to be portable to
> Windows, but can also be used on other platforms. If your code didn't
> need to be portable to other platforms, you could, by definition, rely
> upon Window's own guarantees about wchar_t.

I agree, but unfortunately both the C and C++ standards require 
`wchar_t` to be able represent all code points in the largest supported 
extended character set, and while that requirement worked nicely with 
original Unicode, already in 1992 or thereabouts (not quite sure) it was 
in conflict with extremely firmly established practice in Windows.

Bringing the standards in agreement with actual practice should be a 
goal, but for C++ it's seldom done.

It /was/ done, in C++11, for the hopeless idealistic C++98 goal of clean 
C++-ish `<c...>` headers that didn't pollute the global namespace. But 
C++17 added stuff to only some `<c...>` headers and not to the 
corresponding `<... .h>` headers, and that fact was then used quite 
recently in a proposal to un-deprecate the .h headers but add all new 
stuff only to `<c...>` headers. Which satisfies the politics but not the 
in-practice of using code that uses C libraries designed as 
C++-compatible, without running afoul of qualification issues.

And it /was/ done, in C++11, for both `throw` specifications and for the 
`export` keyword, not to mention the C++11 optional conversion between 
function pointers and `void*`, in order to support the reality of Posix.

But it seems to me, it's very very hard to get such changes through the 
committee, just as individual people generally don't like to admit that 
they've been wrong. Instead, C++20 started on a path of /introducing/ 
more conflicts with reality. In particular for `std::filesystem::path`, 
where they threw the baby out with the bathwater for purely academic 
idealism reasons.

- Alf

Thread

How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-06-30 07:57 +0000
  Re: How to write wide char string literals? Kli-Kla-Klawitter <kliklaklawitter69@gmail.com> - 2021-06-30 10:05 +0200
    Re: How to write wide char string literals? Ralf Goertz <me@myprovider.invalid> - 2021-06-30 10:30 +0200
      Re: How to write wide char string literals? Kli-Kla-Klawitter <kliklaklawitter69@gmail.com> - 2021-06-30 12:37 +0200
        Re: How to write wide char string literals? Ralf Goertz <me@myprovider.invalid> - 2021-07-01 09:19 +0200
          Re: How to write wide char string literals? Kli-Kla-Klawitter <kliklaklawitter69@gmail.com> - 2021-07-01 11:10 +0200
            Re: How to write wide char string literals? Ralf Goertz <me@myprovider.invalid> - 2021-07-01 11:36 +0200
              Re: How to write wide char string literals? Kli-Kla-Klawitter <kliklaklawitter69@gmail.com> - 2021-07-01 16:17 +0200
                Re: How to write wide char string literals? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-07-01 10:13 -0700
                Re: How to write wide char string literals? Kli-Kla-Klawitter <kliklaklawitter69@gmail.com> - 2021-07-01 19:27 +0200
                Re: How to write wide char string literals? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-07-01 11:21 -0700
                Re: How to write wide char string literals? Real Troll <real.troll@trolls.com> - 2021-07-01 18:45 +0000
                Re: How to write wide char string literals? Kli-Kla-Klawitter <kliklaklawitter69@gmail.com> - 2021-07-02 10:03 +0200
              Re: How to write wide char string literals? Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2021-07-02 02:31 -0700
                Re: How to write wide char string literals? MrSpud_oyCn@92wvlb1hltq4dhc.gov.uk - 2021-07-02 09:38 +0000
                Re: How to write wide char string literals? Paavo Helde <myfirstname@osa.pri.ee> - 2021-07-02 13:52 +0300
                Re: How to write wide char string literals? MrSpud_zg8yg@nx8574z6ey2rc0y563k5i2.net - 2021-07-02 12:53 +0000
                Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-07-02 15:22 +0200
                Re: How to write wide char string literals? Paavo Helde <myfirstname@osa.pri.ee> - 2021-07-02 17:32 +0300
  Re: How to write wide char string literals? Ralf Goertz <me@myprovider.invalid> - 2021-06-30 10:08 +0200
  Re: How to write wide char string literals? MrSpud_r5j@ywn9entw2s.org - 2021-06-30 08:39 +0000
    Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-06-30 10:52 +0000
      Re: How to write wide char string literals? MrSpud_3u59h8@0c9tv3nddl090w2ynhm.gov - 2021-06-30 11:28 +0000
        Re: How to write wide char string literals? David Brown <david.brown@hesbynett.no> - 2021-06-30 14:01 +0200
  Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-06-30 10:55 +0200
    Re: How to write wide char string literals? David Brown <david.brown@hesbynett.no> - 2021-06-30 11:23 +0200
  Re: How to write wide char string literals? Richard Damon <Richard@Damon-Family.org> - 2021-06-30 06:51 -0400
    Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-06-30 11:09 +0000
      Re: How to write wide char string literals? Richard Damon <Richard@Damon-Family.org> - 2021-06-30 07:35 -0400
  Re: How to write wide char string literals? Paavo Helde <myfirstname@osa.pri.ee> - 2021-06-30 14:03 +0300
    Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-06-30 11:13 +0000
      Re: How to write wide char string literals? Richard Damon <Richard@Damon-Family.org> - 2021-06-30 07:39 -0400
        Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-06-30 13:50 +0200
          Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-06-30 14:19 -0400
            Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-07-01 13:31 +0200
        Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-01 04:42 +0000
          Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-01 10:58 -0400
            Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-02 05:26 +0000
              Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-02 01:44 -0400
                Re: How to write wide char string literals? Bo Persson <bo@bo-persson.se> - 2021-07-02 08:33 +0200
                Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-02 11:52 +0000
                Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-02 16:15 -0400
                Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-07-03 03:30 +0200
                Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-03 00:44 -0400
                Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-07-03 13:31 +0200
                Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-03 08:44 -0400
                Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-07-03 16:28 +0200
                Re: How to write wide char string literals? Richard Damon <Richard@Damon-Family.org> - 2021-07-03 11:48 -0400
                Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-08 15:56 -0400
                Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-03 16:59 +0000
                Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-03 17:49 -0400
                Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-08 08:11 +0000
                Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-08 05:52 -0400
                Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-03 06:59 +0000
                Re: How to write wide char string literals? James Kuyper <jameskuyper@alumni.caltech.edu> - 2021-07-03 09:03 -0400
                Re: How to write wide char string literals? Chris Vine <chris@cvine--nospam--.freeserve.co.uk> - 2021-07-03 14:23 +0100
                Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-03 17:06 +0000
                Re: How to write wide char string literals? Richard Damon <Richard@Damon-Family.org> - 2021-07-03 14:06 -0400
                Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-08 08:13 +0000
                Re: How to write wide char string literals? "Alf P. Steinbach" <alf.p.steinbach@gmail.com> - 2021-07-02 15:37 +0200
      Re: How to write wide char string literals? Manfred <noname@add.invalid> - 2021-06-30 16:54 +0200
      Re: How to write wide char string literals? Paavo Helde <myfirstname@osa.pri.ee> - 2021-06-30 17:56 +0300
  Re: How to write wide char string literals? Öö Tiib <ootiib@hot.ee> - 2021-06-30 09:22 -0700
  Re: How to write wide char string literals? Christian Gollwitzer <auriocus@gmx.de> - 2021-07-01 07:19 +0200
    Re: How to write wide char string literals? David Brown <david.brown@hesbynett.no> - 2021-07-01 10:29 +0200
      Re: How to write wide char string literals? Juha Nieminen <nospam@thanks.invalid> - 2021-07-01 08:44 +0000
        Re: How to write wide char string literals? David Brown <david.brown@hesbynett.no> - 2021-07-01 12:58 +0200
      Re: How to write wide char string literals? Christian Gollwitzer <auriocus@gmx.de> - 2021-07-01 14:01 +0200
        Re: How to write wide char string literals? David Brown <david.brown@hesbynett.no> - 2021-07-01 14:57 +0200
    Re: How to write wide char string literals? Manfred <noname@add.invalid> - 2021-07-01 15:44 +0200

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