220 33022 <730d0077-5a80-4dce-8250-19be62b1a23b@isocpp.org> article Path: news.gmane.org!.POSTED!not-for-mail From: Igor Baidiuk Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: std::optional - support for sentinel values Date: Thu, 29 Jun 2017 04:09:16 -0700 (PDT) Lines: 68 Approved: news@gmane.org Message-ID: <730d0077-5a80-4dce-8250-19be62b1a23b@isocpp.org> References: <6e23864f-827a-4bdb-89de-a60d8f5be993@isocpp.org> <9f81f2b9-958c-4018-9f78-a6ac2e425899@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="----=_Part_3153_349885063.1498734556507" X-Trace: blaine.gmane.org 1498734566 10315 195.159.176.226 (29 Jun 2017 11:09:26 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Thu, 29 Jun 2017 11:09:26 +0000 (UTC) To: ISO C++ Standard - Future Proposals Original-X-From: std-proposals+bncBDK4F76SSIIBBXN72PFAKGQEO7X3JYA@isocpp.org Thu Jun 29 13:09:22 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-pg0-f71.google.com ([74.125.83.71]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dQXJx-00026E-Ju for gclcip-std-proposals@m.gmane.org; Thu, 29 Jun 2017 13:09:19 +0200 Original-Received: by mail-pg0-f71.google.com with SMTP id 76sf86304185pgh.11 for ; Thu, 29 Jun 2017 04:09:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=HHl7fsFSyCCN1oQLD+mZA0Q8vlnS6w5UeaiIANi2pxI=; b=l6fwQhKbimolUvrXIabHiXG4Fe80wr5CJjg0+Oqe1Wpjd8Oweeht1jfnPowX72dEzu 8XMBFlzth2UMj9zc5six/hfu2eWIsMa/RLc1serTSGp0i20uLLtP21jQw7jA8HE1SZ2+ x3CVojqc3iD59oEl/mz8t5EwR0MPjeacqsxi2dQCEcpO6tpdXGn3odN5FWFOEzeMDemg JaZhx+ESdwR/QkEu9PGaZoK6rE12xgIzPC1wR4ofzfp2iE9GaOal4zFXNsk9T48fVhZ1 8RQtwGt70sjwFjW8T6B2ttgomVq2jiynZvL7+6BCYqf1+Xozti93OZKI9M62u5TuragV 6jjA== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=date:from:to:message-id:in-reply-to:references:subject:mime-version :x-original-sender:reply-to:precedence:mailing-list:list-id :list-post:list-help:list-archive:list-subscribe:list-unsubscribe; bh=HHl7fsFSyCCN1oQLD+mZA0Q8vlnS6w5UeaiIANi2pxI=; b=FfOIykhxwHizRDhSHTwxQ9WqvwL8OlrhyPZSzkQPBG+GP78AFl246HTpTSx04+x3FU o4/sfy/VjOx0AMZ8RamiAiYWKLUmUTUx2R7lhGlr+Bu+I/HyXn1PcgNuhp38QSkhFknN 53+68KBvtQ7WLk0Bw8/lyY4+Tes2YB89ivMz8yvKO9dpntY0fLuOT4hYkzxJvjB1lmjl MVGGXQsgqLhnMGYB3up9sm8zaBkV56AXD6bhVyd4GOkonlK3DyWHRjsnAU9nc3JBP1Ve /6qHQYrlqrYVqMyRQIJ+ClUf6VUDOUWqrMu//HIsCDA3eh4FqUSAEhf2zctm01Mm69GF pH0A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:message-id:in-reply-to:references :subject:mime-version:x-original-sender:reply-to:precedence :mailing-list:list-id:x-spam-checked-in-group:list-post:list-help :list-archive:list-subscribe:list-unsubscribe; bh=HHl7fsFSyCCN1oQLD+mZA0Q8vlnS6w5UeaiIANi2pxI=; b=nDbfDln1sgvi0yD3C4n6f1/ShpkM2nqQHhUksWmAINhAwxmzdpH2/0rxe2TlxWbiKJ n4Lw5wOEONKUzVfO1xcWcnZTASO5XcO82HmvbhM+aMldLMQql4K3GX4Fmv/n6EHaY/rH 8WQF7tiZj22x52Rftg6rEcW6TBisPCYo7MG7dvbaY5PlSOwfVpYpcBlhSnJ1xSBo8vwg +prel10+oFs6mXjSxylDZJVq+gwRdzLdvoo8GVUgQ8DrH+R4QwclB7XWjELNB63h6Okf TlZvK0WcU8N7bQAPEpX9RsA+/yPcHXxkSGTDX2MPiKMDXwATT1KtG+oryOJW/k+CDOyB j7vA== X-Gm-Message-State: AKS2vOyCBh+GJJs28uS3sb3AJ4rDJGd5V9KT9xrqKYiy5vcfI/sqrLrC 4hIq1eeZ2iBy/OsN X-Received: by 10.98.150.12 with SMTP id c12mr7113137pfe.39.1498734558458; Thu, 29 Jun 2017 04:09:18 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.36.95.209 with SMTP id r200ls2271575itb.21.canary-gmail; Thu, 29 Jun 2017 04:09:17 -0700 (PDT) X-Received: by 10.36.92.21 with SMTP id q21mr37605itb.6.1498734557119; Thu, 29 Jun 2017 04:09:17 -0700 (PDT) In-Reply-To: X-Original-Sender: target.san@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:33022 Archived-At: ------=_Part_3153_349885063.1498734556507 Content-Type: multipart/alternative; boundary="----=_Part_3154_1588380217.1498734556507" ------=_Part_3154_1588380217.1498734556507 Content-Type: text/plain; charset="UTF-8" On Thursday, June 29, 2017 at 1:55:56 PM UTC+3, Ville Voutilainen wrote: > > > It has nothing to do with includes. Altering the definition of > optional to conditionally use > a trait would be remotely feasible, but it would also be an abi-breaking > change. > > Maybe I didn't express it well enough. I meant the case when someone declares such "sentinel" locally for module, and then return that option to unit where sentinel is not known. Then I realized this is well-possible even if new optional would have trait parameter. -- 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/730d0077-5a80-4dce-8250-19be62b1a23b%40isocpp.org. ------=_Part_3154_1588380217.1498734556507 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable


On Thursday, June 29, 2017 at 1:55:56 PM UTC+3, Vi= lle Voutilainen wrote:

It h= as nothing to do with includes. Altering the definition of
optional to conditionally use
a trait would be remotely feasible, but it would also be an abi-breakin= g change.


Maybe I didn't express it well enough. I mean= t the case when someone declares such "sentinel" locally for modu= le, and then return that option to unit where sentinel is not known.
The= n I realized this is well-possible even if new optional would have trait pa= rameter.

--
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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/730d0077-5a80-4dce-8250-19be62b1a23b= %40isocpp.org.
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