From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id A83D5385737E; Tue, 19 Jul 2022 18:05:17 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org A83D5385737E From: "cvs-commit at gcc dot gnu.org" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/106201] filesystem::directory_iterator is a borrowable range? Date: Tue, 19 Jul 2022 18:05:17 +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: 13.0 X-Bugzilla-Keywords: rejects-valid X-Bugzilla-Severity: normal X-Bugzilla-Who: cvs-commit 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: Message-ID: In-Reply-To: References: 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 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 19 Jul 2022 18:05:17 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D106201 --- Comment #5 from CVS Commits --- The master branch has been updated by Patrick Palka : https://gcc.gnu.org/g:68f37670eff0b872ce5dfd382c8d8f3206bdfc27 commit r13-1755-g68f37670eff0b872ce5dfd382c8d8f3206bdfc27 Author: Patrick Palka Date: Tue Jul 19 14:04:13 2022 -0400 c++: shortcut bad reference binding [PR94894] In case of l/rvalue or cv-qual mismatch during reference binding, we try to give more helpful diagnostics by computing a bad conversion that allows the mismatch. But in doing so, we may end up considering and instantiating a conversion function that could induce a hard error and in turn cause us to reject otherwise valid code. We could just give up on producing a better diagnostic here, but ideally we'd preserve the better diagnostics for invalid code while avoiding unnecessary template instantiations for valid code. To that end, this patch adapts the bad conversion shortcutting mechanism from r12-3346-g47543e5f9d1fc5 to additionally handle this situation. The main observation from there is that during overload resolution, if = we know we have a strictly viable candidate then we don't need to distingu= ish between an unviable and non-strictly viable candidate. Thus we don't need to distinguish between an invalid and bad conversion either, which is what this patch exploits. Of course, we don't know whether we have a strictly viable candidate until after the fact, so we still need to remember when we deferred distinguishing between an invalid and bad conversion. This patch adds a special conversion kind ck_deferred_bad for this purpose. PR c++/94894 PR c++/105766 PR c++/106201 gcc/cp/ChangeLog: * call.cc (enum conversion_kind): Add ck_deferred_bad enumerato= r. (has_next): Return false for it. (reference_binding): Return a ck_deferred_bad conversion instead of an actual bad conversion when LOOKUP_SHORTCUT_BAD_CONVS is s= et. Remove now obsolete early exit for the incomplete TO case. (implicit_conversion_1): Don't mask out LOOKUP_SHORTCUT_BAD_CON= VS. (add_function_candidate): Set LOOKUP_SHORTCUT_BAD_CONVS iff shortcut_bad_convs. (missing_conversion_p): Also return true for a ck_deferred_bad conversion. * cp-tree.h (LOOKUP_SHORTCUT_BAD_CONVS): Define. gcc/testsuite/ChangeLog: * g++.dg/conversion/ref8.C: New test. * g++.dg/conversion/ref9.C: New test.=