220 11505 <1798793.WG2J7LSt36@tjmaciei-mobl4> article Path: news.gmane.org!not-for-mail From: Thiago Macieira Newsgroups: gmane.comp.lang.c++.isocpp.proposals Subject: Re: Re: Controversy and debate: Uninitialized variables by default is a bug Date: Tue, 17 Jun 2014 20:17:36 -0700 Lines: 42 Approved: news@gmane.org Message-ID: <1798793.WG2J7LSt36@tjmaciei-mobl4> References: <60caa4ef-b32d-40fe-97b6-8918fbb2bd51@isocpp.org> <03f935ac-2f51-46bb-b84b-d37c864e3b04@isocpp.org> Reply-To: std-proposals@isocpp.org NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable X-Trace: ger.gmane.org 1403061468 2023 80.91.229.3 (18 Jun 2014 03:17:48 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Wed, 18 Jun 2014 03:17:48 +0000 (UTC) To: std-proposals@isocpp.org Original-X-From: std-proposals+bncBCB4TK757YBRBVMJQSOQKGQEQNOGE2A@isocpp.org Wed Jun 18 05:17:44 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 1Wx6Na-0003Y1-HL for gclcip-std-proposals@m.gmane.org; Wed, 18 Jun 2014 05:17:42 +0200 Original-Received: by mail-wi0-f198.google.com with SMTP id r20sf211416wiv.9 for ; Tue, 17 Jun 2014 20:17:42 -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-transfer-encoding:content-type; bh=vlQEfJKmm/N99XhAbMNSwW+vYKMXle8m+uIwywfzNsc=; b=QxgNchCodMFlxVoRliWaOtyTXmDfUhlaPisuQBsxGzwGJc+f8Cf51BicqyvKliYE32 +hXWgCZqXYWNQ42eZiw3+2Dmlo3oqNcDohQx5HQuniD0TSlxXdtRL4d3hfy4KRctE0yP bAeZJN5hh/eqIg6YZzkTmfHK2aPFMCvyyYKtsM166m9Tz4SqxsUdFMPWPv5zbw5m8xEY hwDtg6lxAoENdyPoJ7B0xImzy7/CJFUIx9IjjrQsEYD6fz0J2Jo1A6Yn+d8KSLr3UbUm rSFTUhUGb0M8MZBPqgY3ozjSUpz08mpAavBXQgbintIMjI9gDmG415aZpj6LB1nEa99D KKM X-Gm-Message-State: ALoCoQnl/auogjbdbx5RW1Uv5f0E4rRbFAECiZrbjSuYvyUSgrzf0liD9bs/UgPI4oiDTxsU0ZNp X-Received: by 10.180.91.73 with SMTP id cc9mr71338wib.4.1403061462275; Tue, 17 Jun 2014 20:17:42 -0700 (PDT) X-BeenThere: std-proposals@isocpp.org Original-Received: by 10.180.23.105 with SMTP id l9ls518295wif.3.gmail; Tue, 17 Jun 2014 20:17:41 -0700 (PDT) X-Received: by 10.194.89.168 with SMTP id bp8mr27007155wjb.73.1403061461164; Tue, 17 Jun 2014 20:17:41 -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 lh2si708153wjc.142.2014.06.17.20.17.40 for ; Tue, 17 Jun 2014 20:17:40 -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:c86:2c03:2902:6742:775c]) by gondolin.macieira.info (Postfix) with ESMTPSA id 039A911A5C8 for ; Tue, 17 Jun 2014 20:17:40 -0700 (PDT) User-Agent: KMail/4.13 (Linux/3.11.10-11-desktop; KDE/4.13.0; x86_64; ; ) In-Reply-To: <03f935ac-2f51-46bb-b84b-d37c864e3b04@isocpp.org> 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:11505 Archived-At: Em ter 17 jun 2014, =E0s 18:39:25, rouslankorneychuk@gmail.com escreveu: > I don't see how default initialization will actually prevent any bugs. If= a > program reads a variable sooner than intended, or if the variable was not > assigned a value when it was intended, your program still does the wrong > thing regardless of whether the variable was initialized. The only > difference is the program behaves more predictably and therefore easier t= o > debug, but you can get the same predictability by compiling in debug mode= .. I actually dispute that it's easier to debug. If you use a memory debugger like Valgrind, it will be able to point out=20 exactly where an uninitialised variable was used when it was uninitialised.= If=20 it happens to be initialised to zero, Valgrind can't tell intention. That's the same reason why you should not reset pointers to null in=20 destructors. > This might even make certain bugs harder to find because a program that > would otherwise seemingly fail at random might not exhibit any symptoms > until it is run under a very specific set of conditions. --=20 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 --=20 ---=20 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 e= mail 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-proposa= ls/. .