I intend to raise the topic of system headers during this discussion.
Use of contract annotations on C standard library functions would bring
clear benefit to C++ programmers, but would require such annotations to
be present in system headers. If WG21 adopts a contracts syntax that is
not amenable to C or WG14, that would create the potential for WG14 to
adopt a different syntax for C (at some point) either for a similar
contracts facility or for contract-like features like Clang's
nullability attributes
<https://clang.llvm.org/docs/AttributeReference.html#nullability-attributes>
or the proposed bounds checking annotations
<https://discourse.llvm.org/t/rfc-enforcing-bounds-safety-in-c-fbounds-safety/70854>.
I can imagine that C standard library implementors might experience some
amount of consternation if different annotations were to be required for
different languages. Likewise for programmers that provide libraries for
use with both C and C++. I encourage anyone with opinions on this matter
to attend.

Tom.

On 7/26/23 1:33 PM, Timur Doumler via Liaison wrote:
> Dear WG14/WG21 liaison study group,
>
> At our SG21 (Contracts) telecon tomorrow we will be looking at P2885
> "Requirements for a Contracts syntax"
> <https://www.open-std.org/jtc1/sc22/wg21/docs/papers/2023/p2885r0.pdf>.
> One of the questions that this paper asks, and that we intend to poll,
> is (see section 5.8 on page 11):
>
> "Should the Contracts syntax also be standardisable for the C
> programming language? Note that this might be a subset of the syntax
> adopted by WG21, or an alternative spelling for the same constructs
> that is supported by both languages."
>
> If any of you would like to contribute to this discussion, you're very
> welcome to join. Apologies for the short notice.
>
> The telecon is taking place tomorrow – Thursday, 27 July 2023, at
> 15:00 UTC (8 AM Pacific / 11 AM Eastern / 16:00 BST / 17:00 CEST).
> That's 21h 30mins from now. Agenda and Zoom link can be found on the
> wiki page:
> https://wiki.edg.com/bin/view/Wg21telecons2023/Teleconference2023-07-27
>
> Cheers,
> Timur
>
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