From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15720 invoked by alias); 8 Nov 2011 07:44:45 -0000 Received: (qmail 15704 invoked by uid 22791); 8 Nov 2011 07:44:44 -0000 X-SWARE-Spam-Status: No, hits=-2.9 required=5.0 tests=ALL_TRUSTED,AWL,BAYES_00 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; Tue, 08 Nov 2011 07:44:31 +0000 From: "marc.glisse at normalesup dot org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/51013] complex::{imag,real}() should maintain lvalue-returning extension in C++11 Date: Tue, 08 Nov 2011 07:47:00 -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: normal X-Bugzilla-Who: marc.glisse at normalesup dot org X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- 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: 2011-11/txt/msg00734.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D51013 --- Comment #6 from Marc Glisse 2011-11= -08 07:44:27 UTC --- (In reply to comment #4) > I'm sorry, I misunderstood you, you meant C++11 does not mandate the cons= texpr > in the primary. Actually, I guess it doesn't hurt, I agree, it was your expression "per the letter" that confused me, but I am fine with the code. (In reply to comment #5) > Hmm, I think adding the overloads would interfere with usage of complex > temporaries in a constant expression. Really=C2=A0? std::bitset seems to have this kind of overload for operator[= ]. Surprisingly, it is the only type that does, most only have a constexpr constructor, so I am not sure if there is a bug in bitset, a missing feature elsewhere, or if the situations are different. Actually, it seems that with 4.7,libstdc++ provides a constexpr overload for array::operator[] as an extension, which seems to answer the question. Or do you mean that the following would cause trouble (which seems likely, = but I don't have any compiler at hand that supports both constexpr and *this references)? constexpr _Tp real()const&; _Tp&real()&; _Tp real()&&;