220 18284 article Path: news.gmane.org!not-for-mail From: Olaf van der Spek Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Parsing Numbers Date: Fri, 29 May 2015 09:22:03 +0200 Lines: 40 Approved: news@gmane.org Message-ID: References: <555CDDEF.8000002@gmx.net> <555ECB8E.9010606@gmx.net> <55680FE0.9050608@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 X-Trace: ger.gmane.org 1432884126 7803 80.91.229.3 (29 May 2015 07:22:06 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 29 May 2015 07:22:06 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC5NB45SSABBBHFHUCVQKGQE3KHGRTQ@isocpp.org Fri May 29 09:22:05 2015 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wi0-f200.google.com ([209.85.212.200]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1YyEcH-0001vI-Kn for gclcip-std-proposals@m.gmane.org; Fri, 29 May 2015 09:22:05 +0200 Original-Received: by wifx6 with SMTP id x6sf3063022wif.1 for ; Fri, 29 May 2015 00:22:05 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:in-reply-to:references:date :message-id:subject:from: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=aTZKIcTd0bKqaEqP+tAOdzIu6hpunxX4/9c3m4PplTY=; b=BoFoFZVBIucg5a7X1MfMomi03sWRJu5uBt1k4NEj155q2gS0wdFYc3yPXeKMdDPlaw NUSuTZDOQDdExFjqIJLhgR/wUuIm3YrRdBECujjnutwVIyF+IxwrX6cEFVSt5JYj7zS6 HrGuQmqe8GVMCqMkHv3VOu3IUFlSIO6TeEsTEdI16PLMTmnAMaaORRuN1L/+IuskHpS+ zODf01Tg5B3jMihF2Onzp0VObskPGkooJErdRqpGJsy0CbULOjnZln/16ep8TiqYBgZ4 mLzhhB+a/KkFgxvgCip7vZ4Y28wL5pOa+fBCrMei3h8NFzcvFYYQF9n1vQOo1lkv5/kH ktcA== X-Gm-Message-State: ALoCoQmzln18tEvxIJohVv5bLup7LaJBvPvXHb5gIblJHIcckuHs61vu9Aa15qpO7EU6AKAfBz7M X-Received: by 10.180.73.137 with SMTP id l9mr1736297wiv.5.1432884125101; Fri, 29 May 2015 00:22:05 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.102.71 with SMTP id fm7ls76831wib.29.gmail; Fri, 29 May 2015 00:22:04 -0700 (PDT) X-Received: by 10.180.76.100 with SMTP id j4mr3745606wiw.10.1432884124211; Fri, 29 May 2015 00:22:04 -0700 (PDT) Original-Received: from mail-wg0-x230.google.com (mail-wg0-x230.google.com. [2a00:1450:400c:c00::230]) by mx.google.com with ESMTPS id h5si8176270wjz.65.2015.05.29.00.22.04 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 29 May 2015 00:22:04 -0700 (PDT) Received-SPF: pass (google.com: domain of olafvdspek@gmail.com designates 2a00:1450:400c:c00::230 as permitted sender) client-ip=2a00:1450:400c:c00::230; Original-Received: by wgme6 with SMTP id e6so54946019wgm.2 for ; Fri, 29 May 2015 00:22:04 -0700 (PDT) X-Received: by 10.180.8.98 with SMTP id q2mr3637522wia.53.1432884124094; Fri, 29 May 2015 00:22:04 -0700 (PDT) Original-Received: by 10.28.48.18 with HTTP; Fri, 29 May 2015 00:22:03 -0700 (PDT) In-Reply-To: <55680FE0.9050608@gmx.net> X-Original-Sender: olafvdspek@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of olafvdspek@gmail.com designates 2a00:1450:400c:c00::230 as permitted sender) smtp.mail=olafvdspek@gmail.com; dkim=pass header.i=@gmail.com; dmarc=pass (p=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:18284 Archived-At: 2015-05-29 9:06 GMT+02:00 Jens Maurer : >> Would this one work for you? >> error_code parse(T&, string_view&, int base = 10); > > I prefer the iterator-style approach. The style is well-established > in the standard library, can be extended to more general iterators > if someone feels so inclined (not me), has fewer issues with over- Iterator-style is well-established indeed but range-style is more convenient IMO. Can't the string_view one be easily generalized too? > eager aliasing assumptions that prevent compiler optimization, I still don't get the aliasing problem. Isn't that only an issue with writes? Wouldn't doing auto it = is.begin(); auto last = is.end(); be enough? > and can be made to look parallel with output. > Output doesn't work > with string_view at all, because its elements are const. True, but IMO we should punish input for that. > Regarding the aliasing assumptions: It's easy to say "that's the > implementer's job", but I have been unable to coerce gcc into > doing the right thing when examining similar style variations for > output operations, even with gcc's __restrict extension. > Maybe I'm just stupid. -- --- 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/. .