From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id B2259385842C; Mon, 27 Feb 2023 17:03:43 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org B2259385842C
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1677517423;
	bh=PYNP4Xg+u7Op11PAmlUlqT0f8oMRPsaj5RtOkKmxnGE=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=P0gXBTLMO5CRcLsm+0ai1TKCOPbEL3fcaDZNfuW7GJujcBgu3MQ7TnsU8+AfI9ws9
	 GyndQv1YP3D2a+uaJzZPmwAViWBQWYUun2gvMrOXtLItLmourhWCNvmiS2TQdZswbl
	 Gzd4H3mH7QMmNmwHkU4xDRXGDl6ahzS6jnEoWJeo=
From: "redi at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug libstdc++/108952] Regression in
 uses_allocator_construction_args for pair of rvalue references
Date: Mon, 27 Feb 2023 17:03:43 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: libstdc++
X-Bugzilla-Version: 12.1.1
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: redi at gcc dot gnu.org
X-Bugzilla-Status: ASSIGNED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: redi at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_status assigned_to everconfirmed
 cf_reconfirmed_on
Message-ID: <bug-108952-4-GmoL2YbZYk@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-108952-4@http.gcc.gnu.org/bugzilla/>
References: <bug-108952-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D108952

Jonathan Wakely <redi at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |redi at gcc dot gnu=
.org
     Ever confirmed|0                           |1
   Last reconfirmed|                            |2023-02-27

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
The problem is that std::move(pr).first always yields an lvalue, even if the
type of pr is pair<T&&, U&&>.

I tried to simplify uses_allocator_construction_args to avoid indirection,
which I think is the source of this issue.=