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 70CF13857B8E; Mon,  3 Oct 2022 14:15:14 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 70CF13857B8E
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1664806514;
	bh=d2wfEda/QAqODIG7ptZajwlADgvimrZxG9qY9lz2grY=;
	h=From:To:Subject:Date:From;
	b=NunG0LA0/Be8yEWfukvu3wl5D1ZGDdrf1V5r4Ne6b5jpZM7yRNT3bg5Eod72htk0d
	 L4LhwGNkd3KC0KSPPy5vyhkXRdw9qtWcIxqBQrVpzhmAK1ciHHWI0TrqkeqJ0Asz6i
	 fppz8WCqLhympEtkXXmWI94hy09XKnz39wYMN2qc=
From: "lisp2d at rambler dot ru" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c++/107132] New: a temporary object with an x-value is not
 destroyed and is bound to a variable
Date: Mon, 03 Oct 2022 14:15:14 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: new
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: c++
X-Bugzilla-Version: 12.2.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: lisp2d at rambler dot ru
X-Bugzilla-Status: UNCONFIRMED
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P3
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status
 bug_severity priority component assigned_to reporter target_milestone
Message-ID: <bug-107132-4@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=3D107132

            Bug ID: 107132
           Summary: a temporary object with an x-value is not destroyed
                    and is bound to a variable
           Product: gcc
           Version: 12.2.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lisp2d at rambler dot ru
  Target Milestone: ---

a temporary object with an x-value is not destroyed and is bound to a varia=
ble

the question is taken from a social network
https://ru.stackoverflow.com/questions/1450260/=D0=9F=D1=80=D0=BE=D0=B4=D0=
=BB=D0=B5=D0=BD=D0=B8=D0=B5-=D0=B2=D1=80=D0=B5=D0=BC=D0=B5=D0=BD=D0=B8-=D0=
=B6=D0=B8=D0=B7=D0=BD=D0=B8-=D0=B2=D1=80=D0=B5=D0=BC=D0=B5=D0=BD=D0=BD=D0=
=BE=D0=B3=D0=BE-=D0=BE=D0=B1=D1=8A=D0=B5=D0=BA=D1=82=D0=B0-=D0=B2-=D0=BF=D1=
=80=D0=B8=D1=81=D0=B2=D0=B0=D0=B8=D0=B2=D0=B0=D0=BD=D0=B8=D0=B8/1450517#145=
0517

with tests
https://godbolt.org/#z:OYLghAFBqd5QCxAYwPYBMCmBRdBLAF1QCcAaPECAMzwBtMA7AQwF=
tMQByARg9KtQYEAysib0QXACx8BBAKoBnTAAUAHpwAMvAFYTStJg1DIApACYAQuYukl9ZATwDKj=
dAGFUtAK4sGISQBspK4AMngMmAByPgBGmMQgAJykAA6oCoRODB7evv5BaRmOAmER0SxxCcl2mA5=
ZQgRMxAQ5Pn6Btpj2xQwNTQSlUbHxSbaNza15HQrjA%2BFDFSOJAJS2qF7EyOwc5gDM4cjeWADU=
JrtuTjPEmKxn2CYaAIIPj%2BEEx1hXXnUCCmdWTy%2BDmOj1OAHYLMcAH6PCDLY4MVCYVRbFLvE=
wQ06WayfAjEb49P67SEYgAi4NJ/xeLzexxYTHCcPBANBzJexw5xzQDBmIPMAWOTFOu3JzwhZOFo=
oxVjBlOJ7M5M3QIBQ63R5zObixZlJmCBhOO4WOCjQKXYnI55jMwrcmo%2BerxBKyChtdrAOwArG=
4GO6qU8Lbj8T8eZLjho/ayyQqlSq0F51bbztrdfrncc1emqMbTeara6k4Gnb981rfV6fTt5U8yR=
xVrROB7eH4OFpSKhOLbsZZjetNpgsbseKQCJpa6sANb%2BRIAOkkc40AA4uBpEguwR6wbsgvWOJ=
Im6O25xeAoQBph6PVnBYDBECBkbV4yRyJQmsAFMpDF0hAhUAB3ZtDmgLApHQTA9B%2BES0N%2Bf=
4AbwQEgfQCTAFwZhmKQ8F0PEADy8bQf%2BnBDveyCPMQb5HsEqi1A0%2BDNrw/CCCIYjsFIMiCI=
oKjqC2Oh6AYRgoNY1j6HgMQnpAqyoGizqcAAtEqZykqYXYWGYrYKL2Wx6Eq4QQV%2BP74dwvB4p=
g2xDr%2BxBMCkBG1voDb7lxh4cNglHII%2BxDHKoC4BNJASSMcwDIMgxwodO1oQJ2ViWKQxy4IQ=
JADlwyyGReqwIDcWAJHCNm7rwLAgLsuzTokGiBIkuylQEGgelwVUeqQzatu2HDHqe55cZeN4QEg=
RGuc%2BECvu%2Bn5QXpsHoagwGgeBg14SNGGISgvHAAA%2Bo6DDjqN42IThwjDVZFG1CRZFNXty=
DUeE5H0cIojiCxF3sWoB66GhC38UpQkifA4mSb8MlySKikRcpqnqcxYw0TpQ0wbtRkmbwZkWVZd=
a2XVB6NU5D5EG5HleT5XILccEAreO8JhQJkXRfgGPxYlrVaMsKVpSMmU7nupC5YOs5gmYYJcFwA=
RgpViQBLs0j1bwjXNWeI5taQV63t1GO9f14PTbts1gVkys7QZ60ISMABuyApCki161wiSLQYBAO=
otqg%2BTrmHEFtKva0RB0nkdRGnbRrGXUxEjSLdSj3fZui7PohjGKTNi0MJomZRJhKcAA9DG/3W=
Cpx7A5pBBg1NWtDtDu1w5ZBmIxwjbI/ZqPOa57k4ywCgG8cpszpbDr4%2BFgnk7Fbl7AlSVtfTT=
DpZQZcs2zkjTgEqEeokkhlflHpmFItWiw5Es02OpCTh6GjTh6B%2BJFwC5FShkhmAEtU7rsdkNe=
RUu02XZi32L9/JaQevxBkziSEAA%3D

#include <iostream>

int destructions;
struct A { ~A() noexcept { ++destructions; } };

int main() {
  {
    const A& a =3D A{} =3D A{};
    std::cout << "Destructions in scope:     " << destructions << '\n';
    destructions =3D 0;
  }
  std::cout << "Destructions out of scope: " << destructions << '\n';
}

the object under variable a should be dead. But it's still alive.=