220 2926 article Path: news.gmane.org!not-for-mail From: Tony V E Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: std::optional -- request for feedback on the wording Date: Sun, 17 Feb 2013 13:35:45 -0500 Lines: 40 Approved: news@gmane.org Message-ID: References: <511FFA5B.7050204@wanadoo.fr> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: ger.gmane.org 1361126144 14970 80.91.229.3 (17 Feb 2013 18:35:44 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Sun, 17 Feb 2013 18:35:44 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCUZ5QWKNQIIFRUERECRUBHMH6OGY@isocpp.org Sun Feb 17 19:36:06 2013 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 1U795q-0007Wh-B5 for gclcip-std-proposals@m.gmane.org; Sun, 17 Feb 2013 19:36:06 +0100 Original-Received: by mail-lb0-f200.google.com with SMTP id k6sf6014165lbo.3 for ; Sun, 17 Feb 2013 10:35:46 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=x-received:x-beenthere:x-received:x-received:received-spf :mime-version:x-received: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=GPQ/sR8hdplYhCZP410e+H6C2zjtivbcOiOYRtIZ7bw=; b=vjkxUVao0MFqEKSMODFy7n3Snu3faSJtl2g2kvPGxcW4CFt0Rmc4FIrOAt3Ur8cH1h dGx9ZNfgaIISUiF28Gp1hSIhdf3VSJI9lReTtJvHMdD0iLx+tREvH/UpxxhYmz4HlNB1 CWm4gNS0TjQVihLFxdedlBC/zl1ww24JRUNz8z4GVPHPBe+0WqS2+0wVR5+0QFl4vog9 Tk65WY/W340nUbx52Ed8RNaUn+KAuDHa8hLqEMPhoEUjYJUTCa6KD/ZLrzMr3GfqEcfj QSqcKdfv2zKlCa4AF67nzGnmJjZT7a8sA7+RniXtYhkxVLpzf X-Received: by 10.112.44.134 with SMTP id e6mr1300716lbm.8.1361126146306; Sun, 17 Feb 2013 10:35:46 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.152.133.144 with SMTP id pc16ls134590lab.49.gmail; Sun, 17 Feb 2013 10:35:45 -0800 (PST) X-Received: by 10.112.29.201 with SMTP id m9mr4715807lbh.96.1361126145817; Sun, 17 Feb 2013 10:35:45 -0800 (PST) X-Received: by 10.112.29.201 with SMTP id m9mr4715805lbh.96.1361126145648; Sun, 17 Feb 2013 10:35:45 -0800 (PST) Original-Received: from mail-lb0-f182.google.com (mail-lb0-f182.google.com [209.85.217.182]) by mx.google.com with ESMTPS id o4si12765449lbg.108.2013.02.17.10.35.45 (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Sun, 17 Feb 2013 10:35:45 -0800 (PST) Received-SPF: pass (google.com: domain of tvaneerd@gmail.com designates 209.85.217.182 as permitted sender) client-ip=209.85.217.182; Original-Received: by mail-lb0-f182.google.com with SMTP id gg6so3706833lbb.41 for ; Sun, 17 Feb 2013 10:35:45 -0800 (PST) X-Received: by 10.112.100.199 with SMTP id fa7mr4685337lbb.28.1361126145482; Sun, 17 Feb 2013 10:35:45 -0800 (PST) Original-Received: by 10.112.14.75 with HTTP; Sun, 17 Feb 2013 10:35:45 -0800 (PST) In-Reply-To: X-Original-Sender: tvaneerd@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of tvaneerd@gmail.com designates 209.85.217.182 as permitted sender) smtp.mail=tvaneerd@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:2926 Archived-At: On Sun, Feb 17, 2013 at 1:34 PM, Tony V E wrote: > On Sat, Feb 16, 2013 at 4:30 PM, Vicente J. Botet Escriba > wrote: >> >> >> * optional::optional(const optional& rhs); >> >> What about adding a post-condition on the copied value >> false == bool(rhs) || rhs.value() == this->value() >> > > You can't guarantee rhs.value() == this->value() for all T. You are > probably assuming T is Regular. > > >> >> What about adding a post-condition on the copied value >> v == this->value() >> > > Same here. > > > Tony P.S. Doesn't mean you can't add some wording, but it might not be quite as simple as you would expect. -- --- 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/?hl=en. .