220 16062 <1932997.CYfMEhPeyI@tjmaciei-mobl4> article Path: news.gmane.org!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: const T* operator->() const Date: Thu, 05 Feb 2015 17:04:04 -0800 Lines: 34 Approved: news@gmane.org Message-ID: <1932997.CYfMEhPeyI@tjmaciei-mobl4> References: <56a7727d-9839-45c9-be72-a6ecb61f38c9@isocpp.org> <2900481.dbBOWPyqhq@tjmaciei-mobl4> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: ger.gmane.org 1423184649 30887 80.91.229.3 (6 Feb 2015 01:04:09 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 6 Feb 2015 01:04:09 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBBVG2CTAKGQEONIEJXA@isocpp.org Fri Feb 06 02:04:09 2015 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-we0-f200.google.com ([74.125.82.200]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YJXL6-0005U8-G1 for gclcip-std-proposals@m.gmane.org; Fri, 06 Feb 2015 02:04:08 +0100 Original-Received: by mail-we0-f200.google.com with SMTP id m14sf8117856wev.3 for ; Thu, 05 Feb 2015 17:04:07 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:user-agent :in-reply-to:references:mime-version:content-type:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe; bh=ewZQV8rNFg8Om+8JhgcCJeKGxM+mRgt+hmzIprkAqJY=; b=X5EnUFSLpS3J3zO0C4yHn4vKt1dLDdJZRx1rjZcppYya7CTKgyEaaluMlYXjKEAkxC evAGgi3r/+o3iJ+m/2DKr4my3H8HgL6WrrEn/1ajEO5dC4I2cMDgDSWhmguFAR8F4bk6 J47UKDPGE0SRSnauEJfzk/6QFrsOnhHB5a5yqgMaxy6mC7PTb+DfS+H38JB0+/cxvw47 kmHUtADDFBAUM/g3NnDsnlXvgLnSCDE9G1yJSXwK9My14qEzh9gJbiPSzsREb8/VuHU+ qAfPfTK3bZtz9VTvrVrMyvrpXc3aqZ5ccBPI75iaokcvZXNkMexONV6tZPOGLjFgXlmL iIxQ== X-Gm-Message-State: ALoCoQlMzAKPbQqiLZSwWIeIQq53E3Vz4s5u0Wo0hz7kYeqo10X6k95QF08hRJnvZ+FYvaIs6/tM X-Received: by 10.112.181.198 with SMTP id dy6mr91881lbc.22.1423184647717; Thu, 05 Feb 2015 17:04:07 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.101.1 with SMTP id fc1ls39553wib.16.canary; Thu, 05 Feb 2015 17:04:06 -0800 (PST) X-Received: by 10.194.2.240 with SMTP id 16mr2018600wjx.108.1423184646494; Thu, 05 Feb 2015 17:04:06 -0800 (PST) Original-Received: from gondolin.macieira.info (gondolin.macieira.info. [2a01:4f8:d13:f81:21c:14ff:fe01:12a3]) by mx.google.com with ESMTP id el2si1363619wid.21.2015.02.05.17.04.06 for ; Thu, 05 Feb 2015 17:04:06 -0800 (PST) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) client-ip=2a01:4f8:d13:f81:21c:14ff:fe01:12a3; Original-Received: from tjmaciei-mobl4.localnet (jfdmzpr01-ext.jf.intel.com [134.134.139.70]) by gondolin.macieira.info (Postfix) with ESMTPSA id BFC9C11A634 for ; Thu, 5 Feb 2015 17:04:05 -0800 (PST) User-Agent: KMail/4.14.4 (Linux/3.11.10-25-desktop; KDE/4.14.4; x86_64; ; ) In-Reply-To: X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) smtp.mail=thiago@macieira.org Precedence: list Mailing-list: list std-proposals@isocpp.org; contact std-proposals+owners@isocpp.org List-ID: X-Google-Group-Id: 399137483710 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.proposals:16062 Archived-At: On Friday 06 February 2015 01:06:54 mobi phil wrote: > > QSharedDataPointer does COW using operator->. > > > > However, it copies when you call the non-const operator->, even if your > > use is > > read-only. > > then you may agree that there would be some added value in such a > construct... Does not make sense to copy if the method is read-only, isn't > it? That doesn't work if I'm accessing a member. For example, the expression type->member Is an lvalue and could be assigned to. But that doesn't mean that it is assigned to, so the operator-> would have no choice but to copy and assume that you do. -- Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center PGP/GPG: 0x6EF45358; fingerprint: E067 918B B660 DBD1 105C 966C 33F5 F005 6EF4 5358 -- --- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Future Proposals" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-proposals+unsubscribe@isocpp.org. To post to this group, send email to std-proposals@isocpp.org. Visit this group at http://groups.google.com/a/isocpp.org/group/std-proposals/. .