220 11808 article Path: news.gmane.org!not-for-mail From: Ville Voutilainen Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: N4078: Rvalue reference overloads for value() method returns object by value Date: Thu, 10 Jul 2014 17:44:27 +0300 Lines: 32 Approved: news@gmane.org Message-ID: References: <4DA018C3-2327-4F55-B7F8-7988EC7B789A@gmail.com> <1a858a77-310b-4591-aaf5-960c40d9f5fc@isocpp.org> <66AF41C1-CB37-4311-98EA-D47DBC6068DC@gmail.com> <66c38b61-7a95-4ace-b34f-2346bb334fb9@isocpp.org> <6F4B3C72-9962-48DC-8527-0C89EA1B9710@gmail.com> <35873CE5-ED8C-4C03-A6A1-E4132DECD91F@gmail.com> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1405003487 10787 80.91.229.3 (10 Jul 2014 14:44:47 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 10 Jul 2014 14:44:47 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC5JHI7A7ALRBTGN7KOQKGQEL7SRZVY@isocpp.org Thu Jul 10 16:44:40 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-oa0-f70.google.com ([209.85.219.70]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1X5FaH-0008Fb-Js for gclcip-std-proposals@m.gmane.org; Thu, 10 Jul 2014 16:44:29 +0200 Original-Received: by mail-oa0-f70.google.com with SMTP id o6sf17219706oag.5 for ; Thu, 10 Jul 2014 07:44:28 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe:content-type:content-transfer-encoding; bh=j8TneZB7pc3qcFucwi1+VQNc6nUsYoNnOoO/vkT237A=; b=GwJVHhTetMX8CL4Zx1E+YiWOefXI4BGQYjWrmS5p8B1ngb93jkCGGhHUTwZF73v6tL wwkC7V6xWzbbcw7wj2WoIyBUaYfdFSiSq8+9AI/0swoEYX6nr1nGGF2XEhmSKHNe3j6s Tzn3jlG2AupUXt/HHFzKrpmmH+ytTfWGyvqb4BFs/x5cEh6f1DSsLesur28vpFU/iWG8 EwQD3t1r13xqfAowM1lr5q2K5+NOpvXvO+Cd9iYB96xBiUBPw7iIIxvhkSWY9cSYeU0J pPcCzmkI0MOtLgb6RDoIy1hgbLRl5x2aiSSZoeU6qwEFmnoEfs4nAQ3MwNPZJEiYCK46 kMvg== X-Gm-Message-State: ALoCoQnEu3/Oz/oRj7EX+IjeY4HffxEtVZAqFoL3GLF/eqmQ1bGSMcV9lylSippgJ9hvHIkBPLPH X-Received: by 10.42.119.148 with SMTP id b20mr12428296icr.33.1405003468706; Thu, 10 Jul 2014 07:44:28 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.140.39.6 with SMTP id u6ls81439qgu.59.gmail; Thu, 10 Jul 2014 07:44:28 -0700 (PDT) X-Received: by 10.140.16.67 with SMTP id 61mr61504559qga.28.1405003467996; Thu, 10 Jul 2014 07:44:27 -0700 (PDT) Original-Received: from mail-qg0-x22a.google.com (mail-qg0-x22a.google.com [2607:f8b0:400d:c04::22a]) by mx.google.com with ESMTPS id z7si8332677qal.15.2014.07.10.07.44.27 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Thu, 10 Jul 2014 07:44:27 -0700 (PDT) Received-SPF: pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:400d:c04::22a as permitted sender) client-ip=2607:f8b0:400d:c04::22a; Original-Received: by mail-qg0-f42.google.com with SMTP id e89so7777723qgf.29 for ; Thu, 10 Jul 2014 07:44:27 -0700 (PDT) X-Received: by 10.140.109.118 with SMTP id k109mr75896302qgf.98.1405003467827; Thu, 10 Jul 2014 07:44:27 -0700 (PDT) Original-Received: by 10.224.31.137 with HTTP; Thu, 10 Jul 2014 07:44:27 -0700 (PDT) In-Reply-To: <35873CE5-ED8C-4C03-A6A1-E4132DECD91F@gmail.com> X-Original-Sender: ville.voutilainen@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:400d:c04::22a as permitted sender) smtp.mail=ville.voutilainen@gmail.com; dkim=pass header.i=@gmail.com; dmarc=pass (p=NONE dis=NONE) header.from=gmail.com 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:11808 Archived-At: On 10 July 2014 17:24, David Krauss wrote: > A return-by-reference from a non-ref-discriminated accessor devolving to > return-by-copy would regress legacy code, but that doesn=E2=80=99t make s= uch library > behavior semantically sound from a modern point of view. The "modern point of view" should include the forwarding concerns, which are not limited to the performance of emplace. > The rvalue-ref-qualified signatures need to return T&& instead of T. > LEWG needs an NB comment > to be able to make that fix for Fundamentals v1, and I'm going to provide > them > with one. > > > The rvalue-ref-qualified signatures of what, std::optional? That=E2=80=99= s not a Uh.. yes. That's the topic of this thread. --=20 ---=20 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 e= mail 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-proposa= ls/. .