220 5230 article Path: news.gmane.org!not-for-mail From: Mikhail Semenov Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Teachability problems with std::move Date: Wed, 26 Jun 2013 12:10:58 +0100 Lines: 93 Approved: news@gmane.org Message-ID: References: <73cad38f-c1b6-4ce3-bfc1-e4a660dbb638@isocpp.org> <09ec0612-ac10-48fb-a186-bd3c200bd5fe@isocpp.org> <20f56505-2fba-4041-9d81-26088e67dc5d@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: multipart/alternative; boundary=089e0149c80041a66304e00cb370 X-Trace: ger.gmane.org 1372245064 17776 80.91.229.3 (26 Jun 2013 11:11:04 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 26 Jun 2013 11:11:04 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDC55PNFRYGRBQ4YVOHAKGQE2ZKOV2Q@isocpp.org Wed Jun 26 13:11:02 2013 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 1Urncr-0000Ur-IK for gclcip-std-proposals@m.gmane.org; Wed, 26 Jun 2013 13:11:01 +0200 Original-Received: by mail-oa0-f70.google.com with SMTP id i4sf63694129oah.1 for ; Wed, 26 Jun 2013 04:11:00 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-beenthere: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:x-google-group-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe :content-type; bh=Pz59H9UA74Jd1nxxdSAjQ1zNICtG3ekifYMT0LCbTUo=; b=ZxIXHGIjrv9OcLLxhl2ndhQcu+etPCEP3hoLiXUdK9MZHsoYNgfxbzyoDRHqrhwtfz qAulpJ+m3AyAes/G5mbV92l9jMb6vhRyLznpRFPTIQeILmK9EG3uklwf7HegWj9x4Q2t HEjjx4h+qv1ADaQW3eIU0e8wj2VLf6KSr0dJGcmg1ZYoMnmdOmdPbZpsZN/PYpsDTaMO /c/woYkPEL4cxQl83o0Or9qC0I8onjVJCLyUbmTqn2nobQfZwIhUPeExwLuwnmaS27i0 T5a3Zt+oi0cmSTEwBK7k3EcD2eIAVaInA2ZUeAMu4Zdn8nKtRk6ebrxz+oVohhorc5CX 4BoQ== X-Received: by 10.182.226.170 with SMTP id rt10mr652549obc.13.1372245060555; Wed, 26 Jun 2013 04:11:00 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.182.66.103 with SMTP id e7ls68456obt.58.gmail; Wed, 26 Jun 2013 04:10:58 -0700 (PDT) X-Received: by 10.60.84.147 with SMTP id z19mr215702oey.21.1372245058773; Wed, 26 Jun 2013 04:10:58 -0700 (PDT) Original-Received: from mail-oa0-x22b.google.com (mail-oa0-x22b.google.com [2607:f8b0:4003:c02::22b]) by mx.google.com with ESMTPS id ko2si223376oeb.7.2013.06.26.04.10.58 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 26 Jun 2013 04:10:58 -0700 (PDT) Received-SPF: pass (google.com: domain of mikhailsemenov1957@gmail.com designates 2607:f8b0:4003:c02::22b as permitted sender) client-ip=2607:f8b0:4003:c02::22b; Original-Received: by mail-oa0-f43.google.com with SMTP id i7so14755183oag.30 for ; Wed, 26 Jun 2013 04:10:58 -0700 (PDT) X-Received: by 10.60.41.66 with SMTP id d2mr212713oel.28.1372245058494; Wed, 26 Jun 2013 04:10:58 -0700 (PDT) Original-Received: by 10.60.14.2 with HTTP; Wed, 26 Jun 2013 04:10:58 -0700 (PDT) In-Reply-To: <20f56505-2fba-4041-9d81-26088e67dc5d@isocpp.org> X-Original-Sender: mikhailsemenov1957@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of mikhailsemenov1957@gmail.com designates 2607:f8b0:4003:c02::22b as permitted sender) smtp.mail=mikhailsemenov1957@gmail.com; dkim=pass header.i=@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:5230 Archived-At: --089e0149c80041a66304e00cb370 Content-Type: text/plain; charset=ISO-8859-1 > Coming back to the original topic, are you really suggesting the code above is the ideal form for teaching when to use std::move and when > not to? I think "return result;" is much simpler. If you have to convert from std::unique_ptr to std::unique_ptr the following code *WON'T COMPILE*; *return result;* *Try it in your compiler!* My point is that if you have to convert (from std::unique_ptr to std::unique_ptr) write it explicitly: *return std::unique_ptr(std::move(result));* If you don't have to convert (you use the same unque_ptr types) than yes write as you said: ** *return result*. -- --- 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/. --089e0149c80041a66304e00cb370 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable
> Coming= back to the original topic, are you really suggesting the code above is th= e ideal form for teaching when to use std::move and when > not to?=A0 I = think "return result;" is much simpler.
=A0
If you have to convert from std::unique_ptr<Foo> to std:= :unique_ptr<const Foo>
the following code WON'T COMPILE;
return result;
=A0
Try it in your compiler!
=A0
My point is that if you have to convert=A0 (from std::unique_p= tr<Foo> to std::unique_ptr<const Foo>) write it explicitly:
=A0
return std::unique_ptr<const Foo>(std::move(resu= lt));
=A0
If you don't have to convert (you use the = same unque_ptr types) than yes write as you = said:
=A0
return result.

=A0

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