220 11788 article Path: news.gmane.org!not-for-mail From: David Krauss 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 14:26:21 +0800 Lines: 31 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> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 (Mac OS X Mail 7.3 \(1878.6\)) Content-Type: text/plain; charset=ISO-8859-1 X-Trace: ger.gmane.org 1404973595 30912 80.91.229.3 (10 Jul 2014 06:26:35 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 10 Jul 2014 06:26:35 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCW25A7E3QCRBEXE7COQKGQEF2X3ANA@isocpp.org Thu Jul 10 08:26:28 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-qg0-f72.google.com ([209.85.192.72]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1X57oJ-0006Ff-KB for gclcip-std-proposals@m.gmane.org; Thu, 10 Jul 2014 08:26:27 +0200 Original-Received: by mail-qg0-f72.google.com with SMTP id q107sf19579955qgd.7 for ; Wed, 09 Jul 2014 23:26:26 -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:subject:from:in-reply-to:date :message-id:references: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; bh=NSUaxtCHNp+XdvhNdY5SqpY03597hNY5h4ReUji16A4=; b=Mc83IxXykks7fcf9qoxrd8Z9RGNanjhVrP2gqQKVgxdy1YRhZjq1RnZN/9bHVZkDC7 MEtc+vBvro6YSkeJp9gXqwsHzIOJwXuj7qEGu5X7qwpNv1C0b/tilMVO6L57KLLNRENg /3/fFnlalOB104oOtefoqYlGcIZpZCXpt+fw3j/uCp20Ctju0tza1vbYH3SQEj41vG7V k7u7+iBjbzV/pY8oK4o8UDUM1IDx5K68clXYClUqvIr3AeOpcX0cCdbOQKmPQl5N9j/4 BymjKhqzUOPVNW0AlPidx6ksNfkq9QzRfYbzfcDuFNOwNvVeLFP7HDgN1SXZkJZ8ddfN Htkw== X-Gm-Message-State: ALoCoQkH6oVY5Bww6EXMY7Un5+Pm2kvEoS2XZkdUF72zelcE9Hr+AKZKM1aE681YKYeuI8Ur2B4Q X-Received: by 10.236.43.20 with SMTP id k20mr19068030yhb.54.1404973586852; Wed, 09 Jul 2014 23:26:26 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.51.16.229 with SMTP id fz5ls7268igd.1.gmail; Wed, 09 Jul 2014 23:26:26 -0700 (PDT) X-Received: by 10.42.72.198 with SMTP id p6mr52096533icj.52.1404973586237; Wed, 09 Jul 2014 23:26:26 -0700 (PDT) Original-Received: from mail-ig0-x22a.google.com (mail-ig0-x22a.google.com [2607:f8b0:4001:c05::22a]) by mx.google.com with ESMTPS id n4si11515183igp.56.2014.07.09.23.26.26 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 09 Jul 2014 23:26:26 -0700 (PDT) Received-SPF: pass (google.com: domain of potswa@gmail.com designates 2607:f8b0:4001:c05::22a as permitted sender) client-ip=2607:f8b0:4001:c05::22a; Original-Received: by mail-ig0-f170.google.com with SMTP id h15so2747388igd.3 for ; Wed, 09 Jul 2014 23:26:26 -0700 (PDT) X-Received: by 10.42.80.208 with SMTP id w16mr529363ick.83.1404973586118; Wed, 09 Jul 2014 23:26:26 -0700 (PDT) Original-Received: from [172.20.10.2] ([121.54.54.63]) by mx.google.com with ESMTPSA id ro10sm2456919igb.18.2014.07.09.23.26.24 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 09 Jul 2014 23:26:25 -0700 (PDT) In-Reply-To: X-Mailer: Apple Mail (2.1878.6) X-Original-Sender: potswa@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of potswa@gmail.com designates 2607:f8b0:4001:c05::22a as permitted sender) smtp.mail=potswa@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:11788 Archived-At: On 2014-07-10, at 2:23 PM, Ville Voutilainen wrote: > On 10 July 2014 09:20, David Krauss wrote: >> >> On 2014-07-10, at 2:10 PM, tomaszkam@gmail.com wrote: >> And dou you expect the following to also work (example presented above): >> auto&& s = *f.begin(); >> >> >> Assuming you mean * ( f().begin() ), I would expect that to be currently >> broken, but the fix is to forbid begin() and end() on an xvalue because they >> are fundamentally nonsense. It's a minor issue that some would-be ill-formed >> code is currently accepted. > > > These "fundamentally nonsense" operations work perfectly fine in forwarding > scenarios. It's easy enough to bind an xvalue to a name throughout the scope it does not behave as an xvalue. Maybe I don't see exactly what you mean by "forwarding scenario," an example would be nice. -- --- 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/. .