220 18356 <1603866.meDQjFxuP6@tjmaciei-mobl4> article Path: news.gmane.org!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Core Language feature: Multiple assignments from multiple return values via tuple Date: Tue, 02 Jun 2015 13:27:50 -0700 Lines: 28 Approved: news@gmane.org Message-ID: <1603866.meDQjFxuP6@tjmaciei-mobl4> References: <69a59613-6504-466a-9878-786653d6087f@isocpp.org> <6F892DDD-D1C2-446F-84E6-A2B81D096B2B@gmail.com> <9f3a42b5-befc-42e9-b739-654675eb4e02@isocpp.org> 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 1433276892 3965 80.91.229.3 (2 Jun 2015 20:28:12 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Tue, 2 Jun 2015 20:28:12 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBSNDXCVQKGQEBESMHEQ@isocpp.org Tue Jun 02 22:28:01 2015 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-lb0-f200.google.com ([209.85.217.200]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Yzsmx-0006R4-DI for gclcip-std-proposals@m.gmane.org; Tue, 02 Jun 2015 22:27:55 +0200 Original-Received: by lbbti3 with SMTP id ti3sf44709794lbb.1 for ; Tue, 02 Jun 2015 13:27:54 -0700 (PDT) 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=ZcJPI+XckbBg4gFuCg3jvvnJG/vagx/tpN5yT5IiUEw=; b=ZnlrqIZKOE0vsj/bKcoK6JwCKqT3yb4i61UPdNxfS6+xo86wK95853dMEsKZqv4Blw z5SHTap73WIqgFykVDfHZxOSCvt4DIK+rfmSjwcAtgGfa5J2oeQUSnSirRq1H7nSgnKS EqbggkJHqmuH02wilB4c1bBKjggABSzhhhfXxb+q0J7TnQgR9Rh9NUaY/l6bTIFaMbvq gicnpze+WaKgGvKuv1rxLzbjO0RpFURmSARwXCZGUywFjk6sKnMLBLohBXCh30NMe3Lj AzHjnaTiMhZk9lHl7OlCutg+sR7CdY+zXzZgwKiC+aTBk6EvwTA1sHUqAzTncqar/HLJ nXrQ== X-Gm-Message-State: ALoCoQnorRjr/eWaRiXqnSGUJpIMUHtZwmu8aonWM+js1qmgEXx39w1ZGj/NaF3Cd+JZhj/YYGdN X-Received: by 10.180.198.172 with SMTP id jd12mr12827810wic.5.1433276874790; Tue, 02 Jun 2015 13:27:54 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.89.99 with SMTP id bn3ls212864wib.35.gmail; Tue, 02 Jun 2015 13:27:53 -0700 (PDT) X-Received: by 10.194.61.50 with SMTP id m18mr54846123wjr.135.1433276872961; Tue, 02 Jun 2015 13:27:52 -0700 (PDT) Original-Received: from gondolin.macieira.info (gondolin.macieira.info. [2a01:4f8:d13:f81:21c:14ff:fe01:12a3]) by mx.google.com with ESMTP id pz10si32571956wjc.109.2015.06.02.13.27.52 for ; Tue, 02 Jun 2015 13:27:52 -0700 (PDT) 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 (jfdmzpr03-ext.jf.intel.com [134.134.139.72]) by gondolin.macieira.info (Postfix) with ESMTPSA id 647E711B740 for ; Tue, 2 Jun 2015 13:27:52 -0700 (PDT) User-Agent: KMail/4.14.6 (Linux/4.0.4-1-desktop; KDE/4.14.6; x86_64; ; ) In-Reply-To: <9f3a42b5-befc-42e9-b739-654675eb4e02@isocpp.org> 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:18356 Archived-At: On Tuesday 02 June 2015 11:46:48 Nicol Bolas wrote: > Except that there's plenty of elision of potential for user-defined types. > Indeed, modern C++ syntax is designed around the assumption that elision > exists and will make code as fast as possible. Every time you see someone > write `T t = stuff();` instead of an explicit `stuff(&t, );`, you are > implicitly relying on elision to make this fast. > > Why should MRVs undo this syntactic progress? In fact, our investigation showed that compilers optimise inline functions with multiple return values (structs, pairs, tuples) better than those with output parameters. For an example, see https://codereview.qt-project.org/106089. -- 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. 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