220 14125 article Path: news.gmane.org!not-for-mail From: Peter Koch Larsen Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: #pragma once Date: Wed, 22 Oct 2014 17:45:24 +0200 Lines: 39 Approved: news@gmane.org Message-ID: References: <3d0ab5b0-73d9-434a-9ae4-cd47d8275590@isocpp.org> <11313423.lvzWu67DM3@tjmaciei-mobl4> <4406713.Mls04kbNJi@tjmaciei-mobl4> 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 1413992733 17422 80.91.229.3 (22 Oct 2014 15:45:33 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 22 Oct 2014 15:45:33 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBDRIBXXKZQERBFNCT6RAKGQEGY3QSFY@isocpp.org Wed Oct 22 17:45:27 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-la0-f71.google.com ([209.85.215.71]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1Xgy6I-0005dc-Fh for gclcip-std-proposals@m.gmane.org; Wed, 22 Oct 2014 17:45:26 +0200 Original-Received: by mail-la0-f71.google.com with SMTP id gi9sf2211433lab.6 for ; Wed, 22 Oct 2014 08:45:26 -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: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=pBzWxFQzSbbcmTv3Cedkw56nu9bAVSE7XlZPnY/KWz0=; b=IENZWwM7nhkpxTr3Kn9pPdZYbf91tWbCFMB/LWRqLHtj6VEgtETuOKihHkCCV6QtcB TwMimhVnEYgcarZj7V4Em00/k6mV8zKzGEt1Fi0LkbifKakx9XOJ8f/9gYeYFu4TVio9 zJ4wA6JNY19ccAJN5VMALzpuISkEWF6g6MweylYbgYe9ZTEn11MasI9rWwqFjPEaOawK 6cesD4h92MxWT9L//niYBnMDznmZEAI6dyaFZk3kLJ1YI6GzesufhagDuRLhTiekpSUW 1P17406193xnSdzmshSyzCCdZWInmYU8PNb900SWYmoNY9nW9HplA4RhcnOYT93GloD2 Wadg== X-Gm-Message-State: ALoCoQlf5sokreHHZ4Cep/kpIRPFWFQqYhcN/oqZaV6d5QpFJbvw4fCMwA5jTU90c2d3/F4VkGAR X-Received: by 10.112.163.229 with SMTP id yl5mr76393lbb.23.1413992726223; Wed, 22 Oct 2014 08:45:26 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.152.199.38 with SMTP id jh6ls214548lac.9.gmail; Wed, 22 Oct 2014 08:45:24 -0700 (PDT) X-Received: by 10.112.132.34 with SMTP id or2mr10775484lbb.75.1413992724844; Wed, 22 Oct 2014 08:45:24 -0700 (PDT) Original-Received: from mail-la0-x230.google.com (mail-la0-x230.google.com. [2a00:1450:4010:c03::230]) by mx.google.com with ESMTPS id bm5si7264470lbb.59.2014.10.22.08.45.24 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 22 Oct 2014 08:45:24 -0700 (PDT) Received-SPF: pass (google.com: domain of peter.koch.larsen@gmail.com designates 2a00:1450:4010:c03::230 as permitted sender) client-ip=2a00:1450:4010:c03::230; Original-Received: by mail-la0-f48.google.com with SMTP id gi9so3124919lab.21 for ; Wed, 22 Oct 2014 08:45:24 -0700 (PDT) X-Received: by 10.112.200.34 with SMTP id jp2mr42570260lbc.1.1413992724741; Wed, 22 Oct 2014 08:45:24 -0700 (PDT) Original-Received: by 10.152.162.104 with HTTP; Wed, 22 Oct 2014 08:45:24 -0700 (PDT) In-Reply-To: <4406713.Mls04kbNJi@tjmaciei-mobl4> X-Original-Sender: peter.koch.larsen@gmail.com X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of peter.koch.larsen@gmail.com designates 2a00:1450:4010:c03::230 as permitted sender) smtp.mail=peter.koch.larsen@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:14125 Archived-At: On Wed, Oct 22, 2014 at 4:52 PM, Thiago Macieira wrote: > On Wednesday 22 October 2014 12:39:15 Peter Koch Larsen wrote: >> I agree with Thiago. Even if both my compilers support the once pragma >> I stick to include guards. They work if you provide a meaningful name >> (I include my initials and the date of construction so something like >> ... _PKL_2014_10_22). I believe it would save me sixty seconds to >> write #pragma instead. >> If include guards make your compilation slow, you should complain to >> your vendor. > > Just out of curiosity, why does it need to be that complex? You mean why I add my initials and a date? It is in my fingers - perhaps that is the best answer. But if you include stuff from others and they are not as rigoreous as e.g. boost, there is a risk that a "FORMAT_HPP" is not unique. I have been bitten by that once - even if it was a very long time ago. /Peter > > The include guard can be based on a rule of formation based on how the header > itself gets #included. You can't have two of such files getting included in the > same translation unit anyway. You mean something like BOOST_DETAILS_LEXICAL_CAST? You could also do that (I am not sure this is a proper boost macro, btw). But I know that I never create two include-files on the same day with the same name. /Peter -- --- 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/. .