Re: On non-Windows, hard depend on uselocale(3) - Mailing list pgsql-hackers

On Mon, Nov 20, 2023 at 11:36 AM Tom Lane <tgl@sss.pgh.pa.us> wrote:
> Thomas Munro <thomas.munro@gmail.com> writes:
> > BTW is this comment in snprintf.c true?
>
> >  * 1. No locale support: the radix character is always '.' and the '
> >  * (single quote) format flag is ignored.
>
> > It is in the backend but only because we nail down LC_NUMERIC early
> > on, not because of any property of snprintf.c, no?
>
> Hmm, the second part of it is true.  But given that we punt float
> formatting to libc, I think you are right that the first part
> depends on LC_NUMERIC being frozen.

If we are sure that we'll *never* want locale-aware printf-family
functions (ie we *always* want "C" locale), then in the thought
experiment above where I suggested we supply replacement _l()
functions, we could just skip that for the printf family, but make
that above comment actually true.  Perhaps with Ryu, but otherwise by
punting to libc _l() or uselocale() save/restore.