Re: How to write wide char string literals?

From	James Kuyper <jameskuyper@alumni.caltech.edu>
Newsgroups	comp.lang.c++
Subject	Re: How to write wide char string literals?
Date	2021-07-03 09:03 -0400
Organization	A noiseless patient Spider
Message-ID	<sbpn6b$5ut$1@dont-email.me> (permalink)
References	(6 earlier) <sbm82o$1rhp$1@gioia.aioe.org> <sbm94h$fif$1@dont-email.me> <sbmul5$1vu5$1@gioia.aioe.org> <sbns4s$cfd$1@dont-email.me> <sbp1td$1sqn$1@gioia.aioe.org>

Show all headers | View raw

On 7/3/21 2:59 AM, Juha Nieminen wrote:
> James Kuyper <jameskuyper@alumni.caltech.edu> wrote:
>>> In other words, in code like this:
>>>
>>>     const char16_t *str = u"something";
>>>
>>> the stuff between the quotation marks in the source code will use
>>> whatever encoding (ostensibly but not assuredly UTF-8), which the
>>
>> I don't understand why you think that the source code encoding matters.
> 
> Because the source file will most often be a text file using 8-bit
> characters and, in these situations most likely (although not assuredly)
> using UTF-8 encoding for non-ascii characters.

Every comment I made on this sub-thread was prefaced on the absence of
any actual members of the extended character set - I was talking only
about the feasibility of using escape sequences to specify such members.

...
>> Do you know of any implementation of C++ that claims to be fully
>> conforming, for which that is not the case? If so, how do they justify
>> that claim?
> 
> Visual Studio will, by default (ie. with default project settings after
> having created a new project) interpret the source files as Windows-1252
> (which is very similar to ISO-Latin-1).

So, that shouldn't cause a problem for escape sequences, which, as a
matter of deliberate design, consist entirely of characters from the
basic source character set.

>>> Or is it guaranteed that the characters between u" and " will
>>> always be interpreted as UTF-8?
>>
>> Source code characters between the u" and the " will be interpreted
>> according to an implementation-defined character encoding. But so long
>> as they encode {'\\', 'x', 'C', '2', '\\', 'x', 'A', '9'}, you should
>> get the standard-defined behavior for u"\xC2\xA9".
> 
> Yes, but that's not the correct desired character in UTF-16, only in UTF-8.
> You'll get garbage as your UTF-16 string literal.

The 'u' mandates UTF-16, which is the only thing that's relevant to the
interpretation of that string literal. That it is the correct pair of
characters, given that UTF-16 has been mandated. Whether or not it's the
intended character depends upon how well your code expresses your
intentions. Alf says that the character that was intended was U+00A9, so
that code does not correctly express that intention. The correct way to
specify it doesn't depend upon the source character set, it only depends
upon the desired encoding of the string. Each of the following ten
escape sequences is a different portably correct ways of expressing that
intention:

UTF-8: u8"\u00A9\U000000A9"
UTF-16: u"\251\xA9\u00A9\U000000A9"
UTF-32: U"\251\xA9\u00A9\U000000A9"

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

csiph-web