220 31148 article Path: news.gmane.org!.POSTED!not-for-mail From: Zhihao Yuan Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: P0577: No lifetime extension for xvalue . 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[184.173.153.196]) by mx.google.com with ESMTPS id e39si9509659qtb.299.2017.02.26.01.18.05 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Sun, 26 Feb 2017 01:18:06 -0800 (PST) Received-SPF: pass (google.com: domain of bounce+3f9131.69110-std-proposals=isocpp.org@miator.net designates 184.173.153.196 as permitted sender) client-ip=184.173.153.196; Original-Sender: zy@miator.net X-Mailgun-Sending-Ip: 184.173.153.196 X-Mailgun-Sid: WyI3MTBkYiIsICJzdGQtcHJvcG9zYWxzQGlzb2NwcC5vcmciLCAiNjkxMTAiXQ== Original-Received: from mail-wm0-f51.google.com (mail-wm0-f51.google.com [74.125.82.51]) by mxa.mailgun.org with ESMTP id 58b29d4d.7fa0d8330770-smtp-out-n01; Sun, 26 Feb 2017 09:18:05 -0000 (UTC) Original-Received: by mail-wm0-f51.google.com with SMTP id v77so42242911wmv.0 for ; Sun, 26 Feb 2017 01:18:05 -0800 (PST) X-Received: by 10.28.152.212 with SMTP id a203mr3875211wme.36.1488100683924; Sun, 26 Feb 2017 01:18:03 -0800 (PST) Original-Received: by 10.80.173.212 with HTTP; Sun, 26 Feb 2017 01:18:03 -0800 (PST) In-Reply-To: <77eaed66-1df2-4f01-9d94-375eb58b21dc@isocpp.org> X-Gmail-Original-Message-ID: X-Original-Sender: zy@miator.net X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@miator.net; spf=pass (google.com: domain of bounce+3f9131.69110-std-proposals=isocpp.org@miator.net designates 184.173.153.196 as permitted sender) smtp.mailfrom=bounce+3f9131.69110-std-proposals=isocpp.org@miator.net 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:31148 Archived-At: On Fri, Feb 24, 2017 at 10:13 PM, Nicol Bolas wrote: > You say there are concerns with generic programming. But at this point, > these concerns are entirely imaginary; there has been no demonstration that > real, legitimate code would be unable to use this correctly. > > And if the purpose of this feature is to fix the temporary lifetime > extension problem, making a feature that still allows that problem to > manifest very easily (by putting `register` in what is undeniably the wrong > place) seems to not exactly be fixing the problem. We enumerated through all the possible combinations of the caller side's requirements on value category and a dependent calls's value category, and find that your suggestion gives benefit while having no real false positive when caller side's requirements are known. I plan to change the current design, tentatively to what you suggest. Thanks, Nicol :) -- Zhihao Yuan, ID lichray The best way to predict the future is to invent it. ___________________________________________________ 4BSD -- http://blog.miator.net/ -- 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. To view this discussion on the web visit https://groups.google.com/a/isocpp.org/d/msgid/std-proposals/CAGsORuBk4Gq9np6g_%3D4CiDm1cm5u3Oq9O-yVAmXvEEp0haXXmQ%40mail.gmail.com. .