Re: Draft C2Y _BitInt related proposals

On Tue, 7 Jul 2026, Jakub Jelinek wrote:

> > The proposed feature wouldn't actually allow for implementing scanf in 
> > standard C because of the need to pass the right pointer-to-_BitInt type 
> > to va_arg there (though this isn't very likely to be an issue in practice 
> > with scanf implementation, and POSIX has an XSI-marked allowance for 
> > mixing arbitrary pointer types in va_arg, in support of use of %n$ in 
> > scanf).
> 
> Would it be ok to add an exception for this in 7.16.2.2?  If arbitrary
> pointer va_arg compatibility is not feasible for historic reasons, perhaps
> just
> - both types are pointers to qualified or unqualified versions of
>   bit-precise integer types;
> ?

I think that is probably reasonable.

-- 
Joseph S. Myers
[email protected]