From 4233117621331417408 X-Google-Thread: f78e5,52dd3e1082ac085e X-Google-Attributes: gidf78e5,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news4.google.com!news.glorb.com!border1.nntp.dca.giganews.com!nntp.giganews.com!local01.nntp.dca.giganews.com!nntp.speakeasy.net!news.speakeasy.net.POSTED!not-for-mail NNTP-Posting-Date: Mon, 05 Sep 2005 16:50:35 -0500 Return-Path: X-Authentication-Warning: mulga.cs.mu.OZ.AU: fjh set sender to devnull@stump.algebra.com using -f X-Robomod: STUMP, ichudov@algebra.com (Igor Chudov) Delivered-To: std-c++@ucar.edu From: "Vladimir Marko" Newsgroups: comp.std.c++ Subject: Re: unique_ptr Organization: http://groups.google.com Message-ID: <1125927788.249709.307810@g43g2000cwa.googlegroups.com> References: <1125603471.570361.32720@o13g2000cwo.googlegroups.com> <1125782448.174120.58820@g14g2000cwa.googlegroups.com> Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" X-Complaints-To: groups-abuse@google.com User-Agent: G2/0.2 X-HTTP-UserAgent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:1.7.5) Gecko/20041107 Firefox/1.0,gzip(gfe),gzip(gfe) Complaints-To: groups-abuse@google.com Injection-Info: g43g2000cwa.googlegroups.com; posting-host=212.5.205.171; posting-account=0pNYQA0AAAA_FHDSc1l1QneuBRRhQETw X-Greylisting: NO DELAY (Relay+Sender autoqualified); processed by UCSD_GL-v2.1 on mailbox4.ucsd.edu; Mon, 05 September 2005 06:44:18 -0700 (PDT) X-Spamscanner: mailbox4.ucsd.edu (v1.6 Aug 4 2005 15:27:38, -2.8/5.0 3.0.4) X-MailScanner: PASSED (v1.2.8 58326 j85DiHPx059885 mailbox4.ucsd.edu) X-Virus-Scanned: amavisd-new at ucar.edu X-Virus-Scanned: amavisd-new at cs.mu.OZ.AU Approved: Fergus Henderson , moderator of comp.std.c++ X-Virus-Scanned: amavisd-new at cs.mu.OZ.AU Date: Mon, 5 Sep 2005 16:42:29 CST Lines: 50 NNTP-Posting-Host: 65.182.171.162 X-Trace: sv3-VeYtsS0hrv1hS/MBV9bqxQfcM3QUTlQV9oo3Wgb6U67c5XbfC0vDtzClbQ41hUwgLvN1n3E6UOq/KvF!kVf4p67ee/u3wScl4iQdKPwzt7x+VW8FF0eVVCM5jfpfat3jSbQ4X3xgFxEEveTgVrRbj/heBcEr!JPUVCNsh4dKdFFQd8ZVra5XZc6VgYuDok9Qjtcxh5rI= X-Complaints-To: abuse@speakeasy.net X-DMCA-Complaints-To: abuse@speakeasy.net X-Abuse-and-DMCA-Info: Please be sure to forward a copy of ALL headers X-Abuse-and-DMCA-Info: Otherwise we will be unable to process your complaint properly X-Postfilter: 1.3.32 Xref: g2news1.google.com comp.std.c++:2022 Howard Hinnant wrote: [...] > 1. What if the unique_ptr(T* ...) constructors looked as you suggest: > > > explicit unique_ptr(T*&& p); > > AND, said constructors zero'd p? I.e.: > > void foo(T* p) > { > std::unique_ptr up(std::move(p)); > assert(p == 0); > } > > This would actually put teeth into what it means to move from a built-in > pointer type. The ownership of the memory really is transferred away > from the built-in pointer. It would be great in debug mode. In release mode I would like the compiler to optimize away the zeroing statement. ("You don't pay for what you don't need.") [...] > 3. This issue isn't specific to unique_ptr. For any smart pointer for > which the following would be bad: > > T* p = ... > smart_pointer p1(p); > smart_pointer p2(p); Well, this is "almost good" for intrusive_ptr -- it should work, but it provides a bad example for those who don't undestand what's going on under the hood. [...] > Would we be willing to have all standard smart pointers behave in the > same way with respect to how they accept raw pointers (be it rvalue > only, zeroing, whatever)? That would be good for new smart pointers. But for the old ones I'd go for the backward compatibility. Vladimir Marko --- [ comp.std.c++ is moderated. To submit articles, try just posting with ] [ your news-reader. If that fails, use mailto:std-c++@ncar.ucar.edu ] [ --- Please see the FAQ before posting. --- ] [ FAQ: http://www.jamesd.demon.co.uk/csc/faq.html ]