220 14120 <4406713.Mls04kbNJi@tjmaciei-mobl4> article Path: news.gmane.org!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: #pragma once Date: Wed, 22 Oct 2014 07:52:02 -0700 Lines: 42 Approved: news@gmane.org Message-ID: <4406713.Mls04kbNJi@tjmaciei-mobl4> References: <3d0ab5b0-73d9-434a-9ae4-cd47d8275590@isocpp.org> <11313423.lvzWu67DM3@tjmaciei-mobl4> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 X-Trace: ger.gmane.org 1413989534 25776 80.91.229.3 (22 Oct 2014 14:52:14 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 22 Oct 2014 14:52:14 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBFMJT6RAKGQEA3SLU2Q@isocpp.org Wed Oct 22 16:52:09 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wg0-f72.google.com ([74.125.82.72]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1XgxGh-0001oJ-B9 for gclcip-std-proposals@m.gmane.org; Wed, 22 Oct 2014 16:52:07 +0200 Original-Received: by mail-wg0-f72.google.com with SMTP id m15sf2150191wgh.7 for ; Wed, 22 Oct 2014 07:52:07 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:subject:date:message-id:user-agent :in-reply-to:references:mime-version: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=l02/UuS/igyctyAGz2towG4R61oaFHbb48NWoz46Sfc=; b=RIDWR5mKCZ08Xlfb6KkxlF3Zkp0S4UiTlZ0l0wJT0tEMc7AMrsK+DqguBeHgLHUMr+ iY4ScktxU2JH7g4eQIl7OjparN6GpTX/OWCPKOWSXCajg+Oy7YPciKiy8IOKFd1lAaoe VkZgobEFWdO1eA2H4KH7rRsFjF0nA7DmpNQhB55y4RJkWAIGwK/Bq9GyZHJF7LSH6vNY 0LKrfXjvX1Lrw0i7W5Vd7el5JZMYCjyrUYKTFrUTdeT2ZPKc2iSLVMZQWUKOgDMQVumx yDahpn8JWcd66omeiA0+Mv9JEsBmk7OCR6r5NJNsitKMDyWDdYWUafg/KCt8tNoThIx6 L48Q== X-Gm-Message-State: ALoCoQnA9piBJWAvRZLj1vmC+2Pl6aaYfoa/ucwL0eWXXrPt90CA11VF0ZfXQlhSF5CfzeAry4sp X-Received: by 10.112.146.104 with SMTP id tb8mr23351lbb.22.1413989526912; Wed, 22 Oct 2014 07:52:06 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.152.7.142 with SMTP id j14ls20167laa.5.gmail; Wed, 22 Oct 2014 07:52:05 -0700 (PDT) X-Received: by 10.112.142.200 with SMTP id ry8mr42633646lbb.26.1413989525247; Wed, 22 Oct 2014 07:52:05 -0700 (PDT) Original-Received: from gondolin.macieira.info (gondolin.macieira.info. [2a01:4f8:d13:f81:21c:14ff:fe01:12a3]) by mx.google.com with ESMTP id lb6si23581548lac.111.2014.10.22.07.52.04 for ; Wed, 22 Oct 2014 07:52:04 -0700 (PDT) Received-SPF: pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) client-ip=2a01:4f8:d13:f81:21c:14ff:fe01:12a3; Original-Received: from tjmaciei-mobl4.localnet (unknown [IPv6:2601:7:1c80:906:61e1:4e9c:40c8:6f6b]) by gondolin.macieira.info (Postfix) with ESMTPSA id 3B74911B520 for ; Wed, 22 Oct 2014 07:52:04 -0700 (PDT) User-Agent: KMail/4.14 (Linux/3.11.10-21-desktop; KDE/4.14.0; x86_64; ; ) In-Reply-To: X-Original-Sender: thiago@macieira.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of thiago@macieira.org designates 2a01:4f8:d13:f81:21c:14ff:fe01:12a3 as permitted sender) smtp.mail=thiago@macieira.org 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:14120 Archived-At: On Wednesday 22 October 2014 12:39:15 Peter Koch Larsen wrote: > On 10/22/14, Thiago Macieira wrote: > > On Tuesday 21 October 2014 19:01:36 Myriachan wrote: > >> Sure, but that's years off if ever, and there are billions of lines of > >> code > >> in projects using #pragma once now. > > > > So why do we need to change anything? If that code is already working, > > it's > > working. If it's not working, then it won't magically begin working > > tomorrow -- at best, it would become valid from next year on and projects > > wishing compatibility would then begin using it in 2016 or 2017. > > They may as well simply use include guards if they need compatibility. > > 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? 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. -- Thiago Macieira - thiago (AT) macieira.info - thiago (AT) kde.org Software Architect - Intel Open Source Technology Center PGP/GPG: 0x6EF45358; fingerprint: E067 918B B660 DBD1 105C 966C 33F5 F005 6EF4 5358 -- --- 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/. .