220 11512 article Path: news.gmane.org!not-for-mail From: Lawrence Crowl Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Controversy and debate: Uninitialized variables by default is a bug Date: Wed, 18 Jun 2014 13:36:26 -0700 Lines: 29 Approved: news@gmane.org Message-ID: References: <60caa4ef-b32d-40fe-97b6-8918fbb2bd51@isocpp.org> 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 1403123796 3912 80.91.229.3 (18 Jun 2014 20:36:36 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 18 Jun 2014 20:36:36 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBC2NJ44B2QNBBS7QQ6OQKGQEYPABFKI@isocpp.org Wed Jun 18 22:36:29 2014 Return-path: Envelope-to: gclcip-std-proposals@m.gmane.org Original-Received: from mail-wi0-f198.google.com ([209.85.212.198]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1WxMar-0006lq-5t for gclcip-std-proposals@m.gmane.org; Wed, 18 Jun 2014 22:36:29 +0200 Original-Received: by mail-wi0-f198.google.com with SMTP id r20sf1022730wiv.9 for ; Wed, 18 Jun 2014 13:36:28 -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:sender: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=PQj7xSnicdxzA+tVoMt0rh3owkA/hOftCtZwRJR2Xkc=; b=aSuU3Hbg2D4+vO5hISQ5j27f9MFRmfrqzFXWK9/WQ/KukklsntYwTIbiWcpFcNikoT ZQLJgfA1FUlk7dU9Dn82hzSq+WDEnrSBAa+Nn+f383E0CJ2ohDRzAhjp7lcuOtGlHyCC cig0PYFv79IV1yhF1YqtW4E345awe1TaI3QRLw818I2znKGEGnB/fwOHfd6XPpJQCYD3 W/qe8fTSsTGERHSqstaG2+veGfrTNCPK34n/CeOWujl4G7htNQn/36BPKgYlLiQatC+f tP/xOCa1xGqj68R9QTlugoXfnz4tX/alnv/8TJFosbXI5grxg8Nq3ZNoYqx6h89QIXeJ z36g== X-Gm-Message-State: ALoCoQmO1LXBf7IZujcIslqjz9GQQbdDPnxF1amkRz9fZs14NMvSHAF+L0iRknCXf1dpBMhllEA5 X-Received: by 10.112.200.164 with SMTP id jt4mr47321lbc.14.1403123788771; Wed, 18 Jun 2014 13:36:28 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.98.7 with SMTP id ee7ls122743wib.22.gmail; Wed, 18 Jun 2014 13:36:27 -0700 (PDT) X-Received: by 10.194.58.199 with SMTP id t7mr580718wjq.14.1403123787551; Wed, 18 Jun 2014 13:36:27 -0700 (PDT) Original-Received: from mail-wi0-x232.google.com (mail-wi0-x232.google.com [2a00:1450:400c:c05::232]) by mx.google.com with ESMTPS id df8si4566597wjc.1.2014.06.18.13.36.27 for (version=TLSv1 cipher=ECDHE-RSA-RC4-SHA bits=128/128); Wed, 18 Jun 2014 13:36:27 -0700 (PDT) Received-SPF: pass (google.com: domain of lawrence.crowl@gmail.com designates 2a00:1450:400c:c05::232 as permitted sender) client-ip=2a00:1450:400c:c05::232; Original-Received: by mail-wi0-f178.google.com with SMTP id n15so1790578wiw.17 for ; Wed, 18 Jun 2014 13:36:27 -0700 (PDT) X-Received: by 10.194.142.205 with SMTP id ry13mr338229wjb.69.1403123787197; Wed, 18 Jun 2014 13:36:27 -0700 (PDT) Original-Sender: lawrence.crowl@gmail.com Original-Received: by 10.194.56.201 with HTTP; Wed, 18 Jun 2014 13:36:26 -0700 (PDT) In-Reply-To: X-Original-Sender: lawrence@crowl.org X-Original-Authentication-Results: mx.google.com; spf=pass (google.com: domain of lawrence.crowl@gmail.com designates 2a00:1450:400c:c05::232 as permitted sender) smtp.mail=lawrence.crowl@gmail.com; dkim=pass header.i=@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:11512 Archived-At: On 6/17/14, Nevin Liber wrote: > On 17 June 2014 17:49, Matthew Fioravante wrote: >> Please now, convince if you can why this is a bad idea. >> > > Because IMO the correct answer is that the default should be for requiring > users to explicitly initialize the variable, and have a way to mark it the > few times they want an uninitialized variable. All initializing to zero > does is move the problem from something that static analyzers can catch to > something they can't. Emphasized. If every declaration or expression has a fully-defined behavior, then, to the compiler/runtime, no program can be wrong. Undefined behavior is your friend. It means that your program can be detectably wrong. It helps compilers help you find bugs. -- Lawrence Crowl -- --- 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/. .