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From: "cvs-commit at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/98842] optional's spaceship operations generates wrong code when operator== is not present
Date: Fri, 11 Jun 2021 22:25:58 +0000 [thread overview]
Message-ID: <bug-98842-4-Wl617J5w9p@http.gcc.gnu.org/bugzilla/> (raw)
In-Reply-To: <bug-98842-4@http.gcc.gnu.org/bugzilla/>
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98842
--- Comment #4 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jonathan Wakely
<redi@gcc.gnu.org>:
https://gcc.gnu.org/g:4f11586945fffd0ff808c16f2f341f9e85d83749
commit r11-8559-g4f11586945fffd0ff808c16f2f341f9e85d83749
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Jun 7 13:02:15 2021 +0100
libstdc++: Constrain three-way comparison for std::optional [PR 98842]
The operator<=>(const optional<T>&, const U&) operator is supposed to be
constrained with three_way_comparable_with<U, T> so that it can only be
used when T and U are weakly-equality-comparable and also three-way
comparable.
Adding that constrain completely breaks std::optional comparisons,
because it causes constraint recursion. To avoid that, an additional
check that U is not a specialization of std::optional is needed. That
appears to be a defect in the standard and should be reported to LWG.
Signed-off-by: Jonathan Wakely <jwakely@redhat.com>
libstdc++-v3/ChangeLog:
PR libstdc++/98842
* include/std/optional (operator<=>(const optional<T>& const U&)):
Add missing constraint and add workaround for template
recursion.
* testsuite/20_util/optional/relops/three_way.cc: Check that
type without equality comparison cannot be compared when wrapped
in std::optional.
(cherry picked from commit adec14811714e22a6c1f7f0199adc05370f0d8b0)
next prev parent reply other threads:[~2021-06-11 22:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-26 18:09 [Bug libstdc++/98842] New: " nunoplopes at sapo dot pt
2021-01-26 18:56 ` [Bug libstdc++/98842] " gcc@nicholas-schwab.de
2021-01-26 21:45 ` gcc@nicholas-schwab.de
2021-01-26 22:55 ` redi at gcc dot gnu.org
2021-06-07 14:47 ` cvs-commit at gcc dot gnu.org
2021-06-11 22:25 ` cvs-commit at gcc dot gnu.org [this message]
2021-07-22 15:34 ` cvs-commit at gcc dot gnu.org
2021-07-22 15:36 ` redi at gcc dot gnu.org
2024-03-28 11:24 ` redi at gcc dot gnu.org
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