Thank you, Jonathan!
Adding chair for today (Fabio) and co-chairs as FYI.

> We also haven't got a decision on what to do with the new math and
numerics stuff in C23.
True. I see the new utils are not added as part of your paper, so we can
move forward with the paper today. We'll get back to that when we have
SG4's input.
I'll ping Mattias (I thought I did, but must have forgotten to..)

> LEWG should decide whether to incorporate <stdckint.h> as-is if we're not
going to have something like it in time for C++26 (0). (from document)
> C++ has no equivalent currently, but we probably don’t want type-generic
macros like C has. (from P3348R0)
> For stdckdint.h we're not going to use the C header, so should not define
the C macro.

I was referring to this as an open question, as it wasn't voted on yet, but I
know your paper doesn't propose adding it.
I (personally) agree that having this in C++ shape is better (and we might
need a follow-up paper for that), and that it's probably better to have
nothing in 26 than adding the C shape.
Might be worth bringing up in LEWG (and if they do ask to add the C shape
as well, then figure out what to do).

> If it is (in C++ shape), it should be in the __cpp_lib_xxx form.
Sure, makes sense. Thanks :)

*See you soon!*


Best Regards,
Inbal Levi

ISO C++ LEWG Chair & Israeli NB Chair
C++Now Program Chair & CoreC++ Conference Organizer


On Tue, 17 Sept 2024 at 15:59, Jonathan Wakely <cxx_at_[hidden]> wrote:

>
>
> On Tue, 17 Sept 2024 at 13:52, Inbal Levi <sinbal2l_at_[hidden]> wrote:
>
>> Hello SG10,
>> We're in the process of rebasing C++ on C (we will see a paper today) and
>> wanted your input on what to do with the C macros:
>> https://en.cppreference.com/w/c/23
>> (e.g __STDC_VERSION_STDCKDINT_H__
>> <https://en.cppreference.com/mwiki/index.php?title=STDC_VERSION_STDCKDINT_H&action=edit&redlink=1>
>> , __STDC_VERSION_FENV_H__ <https://en.cppreference.com/w/c/numeric/fenv> might
>> be relevant)
>>
>> IIUC, we don't port these?
>>
>
> It's never been a question before, C17 didn't have any such macros.
> They're new in C23.
>
>
>
>>
>> https://gcc.gnu.org/onlinedocs/cpp/Standard-Predefined-Macros.html#Standard-Predefined-Macros-1
>>
>
> I don't think that document is relevant, those macros are defined by
> library headers not the compiler.
>
>
>>
>> Should we consider redefining them in the __cplusplus shape?
>>
>
> The macro for <fenv.h> comes from a C header, and the C++ library doesn't
> add anything to that header. I don't see any point in the C++ library
> requiring new macros for a header that isn't controlled by the C++
> implementation. We also haven't got a decision on what to do with the new
> math and numerics stuff in C23.
>
> For stdckdint.h we're not going to use the C header, so should not define
> the C macro. The proposal to add a C++ version of that header should
> consider whether a feature test macro is needed. If it is, it should be in
> the __cpp_lib_xxx form.
>