Thread

Re: C11: should we use char32_t for unicode code points?

Tatsuo Ishii <ishii@postgresql.org> — 2025-10-24T09:43:15Z

> Now that we're using C11, should we use char32_t for unicode code
> points?
> 
> Right now, we use pg_wchar for two purposes: 
> 
>   1. to abstract away some problems with wchar_t on platforms where
> it's 16 bits; and
>   2. hold unicode code point values
> 
> In UTF8, they are are equivalent and can be freely cast back and forth,
> but not necessarily in other encodings. That can be confusing in some
> contexts. Attached is a patch to use char32_t for the second purpose.
> 
> Both are equivalent to uint32, so there's no functional change and no
> actual typechecking, it's just for readability.
> 
> Is this helpful, or needless code churn?

Unless char32_t is solely used for the Unicode code point data, I
think it would be better to define something like "pg_unicode" and use
it instead of directly using char32_t because it would be cleaner for
code readers.

Best regards,
--
Tatsuo Ishii
SRA OSS K.K.
English: http://www.sraoss.co.jp/index_en/
Japanese:http://www.sraoss.co.jp