From 5638844864757684539 X-Google-Thread: f78e5,d860fade7481e4d8 X-Google-Attributes: gidf78e5,public X-Google-Language: ENGLISH,ASCII-7-bit Path: g2news1.google.com!news3.google.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: Tue, 18 Apr 2006 16:00:01 -0500 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.1.1 (2006-03-10) on ak74.algebra.com X-Spam-Level: *** X-Spam-Status: No, score=3.4 required=5.0 tests=HEADER_SPAM,MISSING_HEADERS, TO_CC_NONE autolearn=disabled version=3.1.1 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) X-Original-To: std-c++@mailman.ucar.edu Delivered-To: std-c++@mailman.ucar.edu Delivered-To: std-c++@ucar.edu From: "Alf P. Steinbach" Newsgroups: comp.std.c++ Subject: Re: tr1::shared_ptr and boost::shared_ptr Message-ID: <4al25bFtp3o9U1@individual.net> References: <1145386359.445242.255260@i39g2000cwa.googlegroups.com> <49-dnXlnpcXN2tjZnZ2dnUVZ_sKdnZ2d@giganews.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Orig-X-Trace: individual.net +Cjx3L5GGxUj4wuQ+Dl23QuBgDnKVXZVaQlULxeB4kN6lgtQC/ User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8) Gecko/20051201 Thunderbird/1.5 Mnenhy/0.7.3.0 X-Greylisting: NO DELAY (Relay+Sender autoqualified); processed by UCSD_GL-v2.1 on mailbox7.ucsd.edu; Tue, 18 April 2006 13:57:25 -0700 (PDT) X-Spamscanner: mailbox7.ucsd.edu (v1.6 Aug 4 2005 15:27:38, 0.0/5.0 3.0.4) X-MailScanner: PASSED (v1.2.8 88487 k3IKvGJM019457 mailbox7.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: Tue, 18 Apr 2006 15:59:40 CST Lines: 41 NNTP-Posting-Host: 65.182.171.162 X-Trace: sv3-mcwoP2eocV8NshiOvSdN2e22AdzNEbhGScnbaaaXkzE1blWtNA4RU2Ml9QGzzsSDaIoWNbYyM1Ees75!fK9aFVJgxG1iRMbeeaZVkwtGy8w56lXMrOVBcghWbvuQxHE6uZ33hYZ8glGoAopR0B/OvVWD7ccE!EVCiLwxbYyo= 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++:1598 * Pete Becker: > Axter wrote: >> What was the justification for the tr1 shared_ptr not to allow a custom >> deleter like the boost::shared_ptr? >> > > There is none. It's part of the TR1 spec. Oops, I didn't notice that. Is there any hope of having a custom delete function added, as with boost::shared_ptr? For example, boost::shared_ptr can be used with a class with protected or private destructor, without being a friend of that class, by passing it a deallocation function that does have access to the destructor. For new code it's presumably no big deal to add friendship for a standard smart-pointer, but code that relies on the above technique with boost::smart_ptr won't work by simply replacing with std::shared_ptr (assuming that's what the TR1 shared_ptr will end up as). In short, it will require workarounds for all code that now uses boost::shared_ptr and relies on the custom deleter, when such code is to be changed to use the standard shared_ptr. And if the class in question can't be changed (adding friendship), then std::shared_ptr can't be used. I think it would reflect badly on the standard library if one had to use boost::shared_ptr /in addition/ to std::shared_ptr. -- A: Because it messes up the order in which people normally read text. Q: Why is it such a bad thing? A: Top-posting. Q: What is the most annoying thing on usenet and in e-mail? --- [ 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.comeaucomputing.com/csc/faq.html ]