220 30704 article Path: news.gmane.org!.POSTED!not-for-mail From: Ville Voutilainen Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Extending explicit specifier Date: Mon, 30 Jan 2017 23:10:43 +0200 Lines: 44 Approved: news@gmane.org Message-ID: References: Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-Trace: blaine.gmane.org 1485810645 26061 195.159.176.226 (30 Jan 2017 21:10:45 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Mon, 30 Jan 2017 21:10:45 +0000 (UTC) To: "ISO C++ Standard - Future Proposals" Original-X-From: std-proposals+bncBC5JHI7A7ALRBVGXX3CAKGQE7VPFKMA@isocpp.org Mon Jan 30 22:10:40 2017 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-it0-f71.google.com ([209.85.214.71]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cYJDk-0006fN-3t for gclcip-std-proposals@m.gmane.org; Mon, 30 Jan 2017 22:10:40 +0100 Original-Received: by mail-it0-f71.google.com with SMTP id 203sf163176640ith.3 for ; Mon, 30 Jan 2017 13:10:45 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=isocpp-org.20150623.gappssmtp.com; s=20150623; h=mime-version:in-reply-to:references:from:date:message-id:subject:to :x-original-sender:x-original-authentication-results:reply-to :precedence:mailing-list:list-id:x-spam-checked-in-group:list-post :list-help:list-archive:list-subscribe:list-unsubscribe; bh=igmOOrtsNE8+W5gbGv8m75kU65f1GXfesTa7CF+5Beg=; b=wJlvkPU8NMIIiAxCxG/Kj6InNQfKev6ge5GyqrvYUmkOQe+LJjeeYyiuMCsO3G8jk5 Rd71jtbkqy53YkeS9zkhLIg/XkTvh3Z9SFuWjTwDWZshi4QsFYvaiSlbcI5YYOlhr8vE iXMOxvdRd3VD05E6bqxCuYW4v2mB1gpaUTveriAmJLar07UgjTOqOVvpZ6Yrp/uqBW0e in74ei2g8gKfMJ7Fau8r7J4ZDPk5rWUo0pFeZP8/M3ulf8S2qIDjDYtJvGzYzMewF9qe mWf7fftElrQq4bIjm9SwJW4L2Y4uhgSLQA4zOxwGmSLI4mD5Foloj0Uu91wBG3FfGdq3 OvxQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:in-reply-to:references:from:date :message-id:subject:to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:x-spam-checked-in-group:list-post:list-help:list-archive :list-subscribe:list-unsubscribe; bh=igmOOrtsNE8+W5gbGv8m75kU65f1GXfesTa7CF+5Beg=; b=r4DSA0WLX2/Ka3P+3whg1IgnIzALQRweXoXwZl/T1fmNtuc+8CHp9JrgACITN1R6p9 pU/QlrVXcQZ1q8WQVFWRbP6IsCjlXGpiza2suM+vOZFodHYWg9e9/yyMqD/XEaWxOwUW SPRZOC3LVtD5J3a2JrRc4hQ88P+JBwPmj7TdJ2g+pQZnOIChUwvPgDvTpi9Tz5XyZWYD Dvr1rXXkvZ/T+VC0m79StE1kVWs2jJ/SX9Ol4BZO7o6Kh+jdgOv0P+rAFKzETegSRit/ Ixx+IbGiMfaIV81uIWRDYufRC6BhM6zNmVWKEwj34m63rGj7Ck5c5ZGnVYgDlaNWPRgg R+5Q== X-Gm-Message-State: AIkVDXJIXA9hYya88Rmdc4rMIW1daWLY8UP3JaUZiLD4g3D5ZJvK+XDZsRFEXKt7HrXfaw== X-Received: by 10.107.136.105 with SMTP id k102mr6925269iod.21.1485810645277; Mon, 30 Jan 2017 13:10:45 -0800 (PST) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.157.18.240 with SMTP id g103ls7843489otg.39.gmail; Mon, 30 Jan 2017 13:10:44 -0800 (PST) X-Received: by 10.202.71.65 with SMTP id u62mr12193293oia.165.1485810644664; Mon, 30 Jan 2017 13:10:44 -0800 (PST) Original-Received: from mail-oi0-x230.google.com (mail-oi0-x230.google.com. [2607:f8b0:4003:c06::230]) by mx.google.com with ESMTPS id e23si5931524otc.149.2017.01.30.13.10.44 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Mon, 30 Jan 2017 13:10:44 -0800 (PST) Received-SPF: pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:4003:c06::230 as permitted sender) client-ip=2607:f8b0:4003:c06::230; Original-Received: by mail-oi0-x230.google.com with SMTP id w204so203110871oiw.0 for ; Mon, 30 Jan 2017 13:10:44 -0800 (PST) X-Received: by 10.202.214.18 with SMTP id n18mr11877362oig.201.1485810644343; Mon, 30 Jan 2017 13:10:44 -0800 (PST) Original-Received: by 10.157.5.225 with HTTP; Mon, 30 Jan 2017 13:10:43 -0800 (PST) In-Reply-To: X-Original-Sender: ville.voutilainen@gmail.com X-Original-Authentication-Results: mx.google.com; dkim=pass header.i=@gmail.com; spf=pass (google.com: domain of ville.voutilainen@gmail.com designates 2607:f8b0:4003:c06::230 as permitted sender) smtp.mailfrom=ville.voutilainen@gmail.com; dmarc=pass (p=NONE sp=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:30704 Archived-At: On 30 January 2017 at 22:55, 'Matt Calabrese' via ISO C++ Standard - Future Proposals wrote: > On Mon, Jan 30, 2017 at 3:41 PM, Richard Thorell > wrote: >> >> Hey, >> >> Since we now have conditional explicit constructors >> (http://en.cppreference.com/w/cpp/utility/optional/optional) maybe we could >> "upgrade" the explicit specifier to work the same way as the noexcept >> specifier by introducing a compile time expression to be evaluated to mark >> the constructor/function explicit. This change wouldn't be any breaking >> change this a simple explicit would evaluate to explicit(true) the same way >> noexcept works. >> >> e.g: >> template >> explicit(std::is_convertible_v) optional(const optional& >> other) >> >> Have this already been thought of? Feedback is welcome :) > > > It's been thought of and talked about by members of the committee, however I > don't know if anyone actually went and wrote a proposal, so you might want > to write the paper if you're up for it (I'd double check the mailings, > first). Stephan Lavavej voiced a desire for this exact facility -- maybe > also ping him and see if he's actively pursuing it? Thought of, sure. Unlike STL, just because I needed it in ten places in the library, I didn't proceed with suggesting it to be standardized. :) Some other people wrote to me to ask for my opinion on whether it should be standardized, my response was "doesn't pass the bar for that, based on my field experience". -- 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/CAFk2RUay5Lb6X0GnnDV3s8Nxo3u4HK3wF4QDBoeiRPp1c%3DqoGw%40mail.gmail.com. .