From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27101 invoked by alias); 9 Sep 2012 17:57:11 -0000 Received: (qmail 27091 invoked by uid 22791); 9 Sep 2012 17:57:10 -0000 X-SWARE-Spam-Status: No, hits=-4.3 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00,KHOP_THREADED X-Spam-Check-By: sourceware.org Received: from localhost (HELO gcc.gnu.org) (127.0.0.1) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Sun, 09 Sep 2012 17:56:57 +0000 From: "redi at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/54388] [4.7/4.8 Regression] std::array.at() const results in undefined behaviour Date: Sun, 09 Sep 2012 17:57:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Keywords: X-Bugzilla-Severity: major X-Bugzilla-Who: redi at gcc dot gnu.org X-Bugzilla-Status: ASSIGNED X-Bugzilla-Priority: P2 X-Bugzilla-Assigned-To: redi at gcc dot gnu.org X-Bugzilla-Target-Milestone: 4.7.2 X-Bugzilla-Changed-Fields: Message-ID: In-Reply-To: References: X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Mailing-List: contact gcc-bugs-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-bugs-owner@gcc.gnu.org X-SW-Source: 2012-09/txt/msg00726.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D54388 --- Comment #13 from Jonathan Wakely 2012-09-09 1= 7:56:15 UTC --- (In reply to comment #10) > Can the compiler warn about the original (buggy) code? It already does: c.cc: In function =E2=80=98A& get(int)=E2=80=99: c.cc:3:43: error: invalid initialization of non-const reference of type =E2= =80=98A&=E2=80=99 from an rvalue of type =E2=80=98A=E2=80=99 A& get(int i) { return i =3D=3D 0 ? a : throw 1; } ^ But warnings are suppressed in system headers. --- Comment #14 from Jonathan Wakely 2012-09-09 1= 7:56:56 UTC --- Author: redi Date: Sun Sep 9 17:56:51 2012 New Revision: 191114 URL: http://gcc.gnu.org/viewcvs?root=3Dgcc&view=3Drev&rev=3D191114 Log: PR libstdc++/54388 * include/std/array (array::at() const): Ensure lvalue result. * testsuite/23_containers/array/element_access/54388.cc: New. * testsuite/23_containers/array/tuple_interface/get_neg.cc: Adjust dg-error line numbers. * testsuite/23_containers/array/tuple_interface/tuple_element_neg.cc: Likewise. Added: trunk/libstdc++-v3/testsuite/23_containers/array/element_access/54388.cc - copied, changed from r191113, trunk/libstdc++-v3/testsuite/23_containers/array/tuple_interface/tuple_elem= ent_neg.cc Modified: trunk/libstdc++-v3/ChangeLog trunk/libstdc++-v3/include/std/array trunk/libstdc++-v3/testsuite/23_containers/array/tuple_interface/get_ne= g.cc =20=20=20 trunk/libstdc++-v3/testsuite/23_containers/array/tuple_interface/tuple_elem= ent_neg.cc