220 16797 <54F91983.2020808@stroustrup.com> article Path: news.gmane.org!not-for-mail From: Bjarne Stroustrup Newsgroups: gmane.comp.lang.c++.isocpp.general,gmane.comp.lang.c++.isocpp.proposals Subject: Re: [c++std-core-27216] Re: An implementation of enhanced auto deduction and abbreviated template syntax using Clang Date: Thu, 05 Mar 2015 22:05:39 -0500 Lines: 29 Approved: news@gmane.org Message-ID: <54F91983.2020808@stroustrup.com> References: Reply-To: std-discussion@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed X-Trace: ger.gmane.org 1425611158 11138 80.91.229.3 (6 Mar 2015 03:05:58 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 6 Mar 2015 03:05:58 +0000 (UTC) Cc: "std-discussion@isocpp.org" , "std-proposals@isocpp.org" , "faisalv@gmail.com" To: c++std-core@accu.org Original-X-From: std-discussion+bncBDDP5YUK74KBBBNT4STQKGQEPRPKORI@isocpp.org Fri Mar 06 04:05:47 2015 Return-path: Envelope-to: gclcig-std-discussion@m.gmane.org Original-Received: from mail-qg0-f72.google.com ([209.85.192.72]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YTia6-0000AU-Ub for gclcig-std-discussion@m.gmane.org; Fri, 06 Mar 2015 04:05:43 +0100 Original-Received: by qgea108 with SMTP id a108sf33430173qge.1 for ; Thu, 05 Mar 2015 19:05:41 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:message-id:date:from:user-agent:mime-version:to :cc:subject:references:in-reply-to:content-type:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe; bh=PlMSkXqkLxPinvkAu0etkhxQ1VvRQ+JhxBSMpC5x1vw=; b=Lph7pmqGspacAqhgF4rRZq7yIBXLhIx0xeWoeiU6NncntUVjVQ6/GIKbYPOlMDnve0 db3Jlww0WxHxF2jBEXKyx/ge3RfurDNsOfCjCadrqw3M20Ztwc3/bwAzdERNK7kSci+5 q4Sm5sYKSjAmMovoaDnCpdhdaqKusWsod2K0KHnBk9qx7U1iDZ0La2peGhEk6Q5OKprm vhpUUidqM0X/0IKmxPx8IT9Ksj0f8+hQ3ccRMMoqvniwGayYRDMGYpBV7VcbfWA3krhU AWoNTowqRlYa1J9rRe1OT/yQb6+l8O3HjCVdNhg8Rfi1u/cNWtTnTISmliSyeaLMD2Ac 65FQ== X-Gm-Message-State: ALoCoQmADx15I6zc9qSFRbeON1cY+JN5OXJlJd0sHz8MV9abYm2t0AHI9/VE8vLdVgdxEWLHxmIM X-Received: by 10.236.110.38 with SMTP id t26mr12263155yhg.1.1425611141799; Thu, 05 Mar 2015 19:05:41 -0800 (PST) X-BeenThere: std-discussion@isocpp.org Original-Received: by 10.140.19.33 with SMTP id 30ls115252qgg.45.gmail; Thu, 05 Mar 2015 19:05:41 -0800 (PST) X-Received: by 10.55.18.14 with SMTP id c14mr24950662qkh.25.1425611141341; Thu, 05 Mar 2015 19:05:41 -0800 (PST) Original-Received: from mail-qc0-f182.google.com (mail-qc0-f182.google.com. [209.85.216.182]) by mx.google.com with ESMTPS id y202si6171916qky.18.2015.03.05.19.05.41 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Mar 2015 19:05:41 -0800 (PST) Received-SPF: none (google.com: bjarne@stroustrup.com does not designate permitted sender hosts) client-ip=209.85.216.182; Original-Received: by qcrw7 with SMTP id w7so47687087qcr.4 for ; Thu, 05 Mar 2015 19:05:41 -0800 (PST) X-Received: by 10.140.150.149 with SMTP id 143mr17580696qhw.4.1425611140932; Thu, 05 Mar 2015 19:05:40 -0800 (PST) Original-Received: from [192.168.1.4] (cpe-24-90-62-156.nyc.res.rr.com. [24.90.62.156]) by mx.google.com with ESMTPSA id n77sm4965598qha.19.2015.03.05.19.05.39 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Mar 2015 19:05:39 -0800 (PST) User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64; rv:31.0) Gecko/20100101 Thunderbird/31.5.0 In-Reply-To: X-Original-Sender: bjarne@stroustrup.com X-Original-Authentication-Results: mx.google.com; spf=none (google.com: bjarne@stroustrup.com does not designate permitted sender hosts) smtp.mail=bjarne@stroustrup.com Precedence: list Mailing-list: list std-discussion@isocpp.org; contact std-discussion+owners@isocpp.org List-ID: X-Google-Group-Id: 495566654649 List-Post: , List-Help: , List-Archive: List-Subscribe: , List-Unsubscribe: , Xref: news.gmane.org gmane.comp.lang.c++.isocpp.general:5003 gmane.comp.lang.c++.isocpp.proposals:16797 Archived-At: (1) people always ask for heavier syntax from new features (2) people learn (3) people always complain that the syntax they insisted on is too heavy handed I remember serious and well-meaning criticism that allowing "sqrt(2)" would lead to misuse and bugs and that it was *good* for people and especially for maintenance if people had to write "sqrt(2.)" or "sqrt((double)2)" to avoid crashes. Yes, someone is going to write "void f(auto);" and be surprised. In particular, someone is going to write "void ff(auto,auto);" and be surprised that "ff("hello",2)" is allowed, but I think that ship has sailed. What we really have to get into our/people's heads is that "auto" is just the weakest constraint. Even a concept that requires nothing is stronger because "void ff(Unconstrained, Unconstrained);" will not accept "ff("hello",2)". There are examples that are better expressed using the less terse notations. We will eventually settle on conventions for use. -- --- You received this message because you are subscribed to the Google Groups "ISO C++ Standard - Discussion" group. To unsubscribe from this group and stop receiving emails from it, send an email to std-discussion+unsubscribe@isocpp.org. To post to this group, send email to std-discussion@isocpp.org. Visit this group at http://groups.google.com/a/isocpp.org/group/std-discussion/. .