[cfp-interest 3651] Re: SNAN* in math.h

[Jim Thomas]

> On Oct 11, 2025, at 4:01 PM, Fred J. Tydeman <tydeman at tybor.com> wrote:
> 
> On Fri, 10 Oct 2025 11:21:32 -0700 Jim Thomas wrote:
>> 
>> Did gcc/glibc not notice the change?
> 
> Since they have both forms
>  math.h/SNAN*
>  float.h/*SNAN
> I assume that they noticed the change.
> 
>> Might the macros be in both places to support existing code?
> 
> Perhaps
> 
>> Are you suggesting CFP propose adding something in C2Y Annex M?
> 
> And also to 7.12 <math.h>
> 
> Something like:
> The SNAN, SNANF, and SNANL macros in <math.h> (added by ????)
> were removed (by N2476) and replaced with DBL_SNAN, FLT_SNAN, and
> LDBL_SNAN in <float.h>.

Not mentioning the change in Annex M seems like an oversight. I would assume that Annex M is the C place of documenting such changes, rather than throughout the standard.

- Jim Thomas

> 
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> Fred J. Tydeman        Tydeman Consulting
> tydeman at tybor.com      Testing, numerics, programming
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