220 13894 <543E8241.7060307@irrequietus.eu> article Path: news.gmane.org!not-for-mail From: George Makrydakis Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Comment on N4191 - Folding expressions (Sutton, Smith) Date: Wed, 15 Oct 2014 17:18:41 +0300 Lines: 49 Approved: news@gmane.org Message-ID: <543E8241.7060307@irrequietus.eu> References: <543E7CB4.7020003@gmx.net> Reply-To: std-proposals@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 1413382620 1521 80.91.229.3 (15 Oct 2014 14:17:00 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 15 Oct 2014 14:17:00 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDFMPCO5SAFRBTUD7KQQKGQEGMJLUEY@isocpp.org Wed Oct 15 16:16:53 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-yh0-f71.google.com ([209.85.213.71]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XePNg-00015I-CW for gclcip-std-proposals@m.gmane.org; Wed, 15 Oct 2014 16:16:48 +0200 Original-Received: by mail-yh0-f71.google.com with SMTP id f73sf3157926yha.2 for ; Wed, 15 Oct 2014 07:16:47 -0700 (PDT) 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 :subject:references:in-reply-to:x-original-sender :x-original-authentication-results:reply-to:precedence:mailing-list :list-id:list-post:list-help:list-archive:list-subscribe :list-unsubscribe:content-type; bh=dPaSzaRU6iZwZKHqyRmkEH80TeR6rww9lMwhiL/+7Wg=; b=IWSjHJAL1oTsLFPJa1hfN6K0wjL/vMlt5j35ne3z5ssS286wx+QJj7SWM79oQAyFR7 JfL4SphPYV2+E/HFO2bcUgclE18vdPf/copJm7hbdfRPSNAkdUd8X/y4nnMD7QO3tuL3 vrePIJ4BtzmzqpkmPwUNYIMpoTE4q2FmO40duhCFN5s4InHReDH9IDjTPxAMH5tsiy9T sc1SQ2e2OU7oK9qJ6tV5zSAvROjrMuxlNxfElJnsOn+YqAKbWPI6nQuYFnEsCnEKMExR SpdwHP4/AMOz9yRp2exe+o96df+Fl0G0wzPZ9o+RK+7BWPEoaeKF0cYv07MT/ZZGnFCM FKXw== X-Gm-Message-State: ALoCoQmOx74QbN75b5rG4m6ZJ8pzaHxNLnIw2ALbTwWmzNKmXpumvpfBh1mTDInmLKg4CSJizdIr X-Received: by 10.236.111.4 with SMTP id v4mr8097984yhg.25.1413382607421; Wed, 15 Oct 2014 07:16:47 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.107.37.208 with SMTP id l199ls234154iol.54.gmail; Wed, 15 Oct 2014 07:16:46 -0700 (PDT) X-Received: by 10.70.138.110 with SMTP id qp14mr12807629pdb.59.1413382606724; Wed, 15 Oct 2014 07:16:46 -0700 (PDT) Original-Received: from sender1.zohomail.com (sender1.zohomail.com. [74.201.84.155]) by mx.google.com with ESMTPS id yt3si15922305pbc.100.2014.10.15.07.16.46 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Wed, 15 Oct 2014 07:16:46 -0700 (PDT) Received-SPF: pass (google.com: domain of george@irrequietus.eu designates 74.201.84.155 as permitted sender) client-ip=74.201.84.155; Original-Received: from [192.168.1.8] (athedsl-03861.home.otenet.gr [87.202.15.51]) by mx.zohomail.com with SMTPS id 1413382603787822.132132559816; Wed, 15 Oct 2014 07:16:43 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 In-Reply-To: <543E7CB4.7020003@gmx.net> X-ZohoMailClient: External X-Zoho-Virus-Status: 2 X-Original-Sender: george@irrequietus.eu X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of george@irrequietus.eu designates 74.201.84.155 as permitted sender) smtp.mail=george@irrequietus.eu 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:13894 Archived-At: On 10/15/2014 04:55 PM, Jens Maurer wrote: > I'd prefer not to derail N4191 with additional features > or depend on other proposals. > > It seems your suggestions are purely add-on and should > be handled in a separate paper. > > Jens I agree with your observation on the first one on expanding this to type parameters (and why not on template-template type ones) being part of a separate paper (are they going to write it?). Regardless, for when values are concerned in folding I do not see how N4191 is derailed. Given that (... op args) and (args op ...) where 'op' is to be an operator during folding (as Sutton and Smith argue), allowing a function (constexpr or not) or a lambda to be used in 'op' would seem a rather good idea: (... [](auto x){ /* implementation here */} args) (... function_identifier args) Such a plain substitution of 'op' for allowing any function identifier / lambda with the same context of use as 'op', does not depend on other proposals nor is there an attempt to create another one for what concerns it. It is a legitimate observation for a likely omission. Regards, George > > On 10/15/2014 01:45 PM, George Makrydakis wrote: [...snip...] > Second, why should the folding expressions be limited to operators using (... + args) and not functions as well, > using (... f args) as well with f being a function identifier, or some sort of other syntax including that f function > can be used with, inspired for example from N4165 / N4174 (uniform function call syntax)? > > Regards, > > George -- --- 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/. .