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Re: u8"" c11 c23

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Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:

> Tim Rentsch <tr.17687@z991.linuxsc.com> writes:
>
>> Keith Thompson <Keith.S.Thompson+u@gmail.com> writes:
>
> [...]
>
>>> The <uchar.h> header was introduced in C99.  In C99, C11, and C17,
>>> that header defines char16_t and char32_t.  C23 introduces char8_t.
>>>
>>> There doesn't seem to be any way, other than checking the value of
>>> __STDC_VERSION__ to determine whether char8_t is defined or not.
>>> There are not *_MIN or *_MAX macros for these types, either in
>>> <uchar.h> or in <limits.h>.  A test program I just wrote would have
>>> been a little simpler if I could have used `#ifdef CHAR8_MAX`.
>
> [...]
>
>> Since C23 defines char8_t to be the same type as unsigned char,
>> it seems better to just define it when it isn't there:
>>
>>     #include <limits.h>
>>
>>     #if CHAR_BIT == 8 && __STDC_VERSION__ < 202311
>>     typedef unsigned char char8_t;
>>     #endif
>
> Yes.  And the test for CHAR_BIT may not be necessary, depending on
> the programmer's intent.  char8_t is the same type as unsigned char
> even if CHAR_BIT > 8.

That's humorous.  It's like a name designed to be confusing or
misleading.  But thank you for the information, I wouldn't have
guessed it.

> Similarly, char16_t and char32_t are the same type as
> uint_least16_t and uint_least32_t, respectively.

Kind of weird, but at least it's consistent, and it explains why
char8_t is the same as unsigned char.  Then again, why not
uint_least8_t?  Has C23 changed to the point where unsigned char
and uint_least8_t have to be the same type?  My recollection is
that in earlier editions of the C standard it is possible, even
if unlikely, for these types to be distinct.

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Re: u8"" c11 c23 Tim Rentsch <tr.17687@z991.linuxsc.com> - 2025-12-15 11:13 -0800
  Re: u8"" c11 c23 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-12-15 14:27 -0800
    Re: u8"" c11 c23 Thiago Adams <thiago.adams@gmail.com> - 2025-12-16 07:57 -0300
      Re: u8"" c11 c23 Keith Thompson <Keith.S.Thompson+u@gmail.com> - 2025-12-16 04:17 -0800
    Re: u8"" c11 c23 Tim Rentsch <tr.17687@z991.linuxsc.com> - 2025-12-21 22:37 -0800

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