As a reminder, we'll be having our C and C++ Compatibility study group
meeting today, in about five hours from now. I hope to see you there!
The full agenda and meeting info are:

Our next meeting will be on Fri Feb 11, 2022 at 18:00 UTC
(https://www.timeanddate.com/worldclock/converter.html?iso=20220211T180000&p1=tz_pt&p2=tz_mt&p3=tz_ct&p4=tz_et&p5=1440).

You can join the meeting at https://iso.zoom.us/j/5513145100

**NEW PASSWORD: same as the old one, but spelled as a C reserved
identifier instead of a C++ keyword; contact Aaron Ballman if you have
questions **

We will be discussing the following papers:

P1774R5 (https://wg21.link/P1774R5) Portable assumptions
Proposes adding a new attribute (spelled [[assume(...)]]) to give
programmers a portable way to provide information to an optimizing
compiler that an expression is true without the compiler executing the
expression. The author is looking for feedback on whether this
proposal would be of interest to WG14 for inclusion in a revision of C
and, if so, whether any modifications are needed to the existing C++
proposal.

P2478R0 (https://wg21.link/P2478R0) _Thread_local for better C++
interoperability with C
Continues the discussion about semantic differences between
_Thread_local (C) and thread_local (C++) that was first identified
during discussion of P2310R0 Revise spelling of keywords at the
November 2021 SG22 meeting. The authors wish to report back on the
discussions that happened in WG14 and see if there is SG22 appetite
for C++ changes to improve compatibility in this realm.

WG14 N2919 (http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2919.pdf)
Relax requirements for variadic parameter lists
This paper proposes allowing a function signature consisting solely of
an ellipsis in C (e.g., void foo(...);) and changes the va_start macro
so that its second argument is optional and never evaluated (only the
first parameter is used). The author is looking for feedback on
whether this proposal will cause compatibility concerns, as WG14 is
intending to add this feature to C23.

Thanks!

~Aaron

On Wed, Jan 26, 2022 at 10:54 AM Aaron Ballman
<compatibility.sg.chair_at_[hidden]> wrote:
>
> Our next meeting will be on Fri Feb 11, 2022 at 18:00 UTC
> (https://www.timeanddate.com/worldclock/converter.html?iso=20220211T180000&p1=tz_pt&p2=tz_mt&p3=tz_ct&p4=tz_et&p5=1440).
>
> You can join the meeting at https://iso.zoom.us/j/5513145100
>
> **NEW PASSWORD: same as the old one, but spelled as a C reserved
> identifier instead of a C++ keyword; contact Aaron Ballman if you have
> questions **
>
> We will be discussing the following papers:
>
> P1774R5 (https://wg21.link/P1774R5) Portable assumptions
> Proposes adding a new attribute (spelled [[assume(...)]]) to give
> programmers a portable way to provide information to an optimizing
> compiler that an expression is true without the compiler executing the
> expression. The author is looking for feedback on whether this
> proposal would be of interest to WG14 for inclusion in a revision of C
> and, if so, whether any modifications are needed to the existing C++
> proposal.
>
> P2478R0 (https://wg21.link/P2478R0) _Thread_local for better C++
> interoperability with C
> Continues the discussion about semantic differences between
> _Thread_local (C) and thread_local (C++) that was first identified
> during discussion of P2310R0 Revise spelling of keywords at the
> November 2021 SG22 meeting. The authors wish to report back on the
> discussions that happened in WG14 and see if there is SG22 appetite
> for C++ changes to improve compatibility in this realm.
>
> Thanks!
>
> ~Aaron