From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 23937 invoked by alias); 24 Aug 2013 19:16:07 -0000 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 Received: (qmail 23908 invoked by uid 48); 24 Aug 2013 19:16:06 -0000 From: "temporal at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug libstdc++/58153] unordered_multimap::erase(iterator) is not constant-time when many entries have the same key Date: Sat, 24 Aug 2013 19:16:00 -0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: changed X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: libstdc++ X-Bugzilla-Version: 4.8.1 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: temporal at gmail dot com X-Bugzilla-Status: UNCONFIRMED 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: Message-ID: In-Reply-To: References: Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/ Auto-Submitted: auto-generated MIME-Version: 1.0 X-SW-Source: 2013-08/txt/msg01267.txt.bz2 http://gcc.gnu.org/bugzilla/show_bug.cgi?id=58153 --- Comment #4 from Kenton Varda --- > This report entry made me wonder why iterators could not just be > pointing to the node just before the one containing the pointed to value. That's a neat idea. I think there is an obscure issue, though. If I have an iterator pointing at item N, and then I (separately) erase item N - 1, what happens to my iterator? But you bring up another, simpler point: why not just have an erase_after() method like forward_list does? That would suit my use case (although at this point I've rewritten it to do something different).