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From: "rodgertq at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/108974] std::barrier except completion function which is not manifestly noexcept
Date: Thu, 02 Mar 2023 02:38:46 +0000 [thread overview]
Message-ID: <bug-108974-4-0H5uF45Es4@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-108974-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=108974
--- Comment #4 from Thomas Rodgers <rodgertq at gcc dot gnu.org> ---
(In reply to Jiang An from comment #3)
> > is_nothrow_invocable_v<CompletionFunction&> shall be true.
>
> If implementation divergence is not intendedly permitted, I don't think it
> makes much sense to introduce UB in this way.
>
> I guess we should either turn it into a mandating requirement:
> > Instantiation of barrier<CompletionFunction> is ill-formed
> > if is_nothrow_invocable_v<CompletionFunction&> is not true.
>
> Or relax the preconditions:
> > If any invocation to the completion function throws an exception,
> > the behavior is undefined.
>
> I've mailed to LWG Chair for this...
LWG Chair has already weighed in on this thread.
libstdc++ and libc++ have essentially the same implementation of std::barrier
(libstdc++'s implementation is derived from libc++'s). So that they behave
consistently and MSVC is different is not surprising.
I don't have a strong opinion on whether this should be UB ore mandated.
Raising an LWG issue seems reasonable.
next prev parent reply other threads:[~2023-03-02 2:38 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-28 19:23 [Bug c++/108974] New: " oliver.rosten at googlemail dot com
2023-02-28 19:24 ` [Bug libstdc++/108974] " pinskia at gcc dot gnu.org
2023-02-28 21:16 ` redi at gcc dot gnu.org
2023-02-28 21:17 ` redi at gcc dot gnu.org
2023-03-02 2:27 ` de34 at live dot cn
2023-03-02 2:38 ` rodgertq at gcc dot gnu.org [this message]
2023-03-02 2:43 ` rodgertq at gcc dot gnu.org
2023-03-02 9:58 ` redi at gcc dot gnu.org
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