From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 17147 invoked by alias); 17 Feb 2011 09:44:53 -0000 Received: (qmail 17134 invoked by uid 22791); 17 Feb 2011 09:44:53 -0000 X-SWARE-Spam-Status: No, hits=-1.9 required=5.0 tests=AWL,BAYES_00,FREEMAIL_FROM,RCVD_IN_DNSWL_NONE,T_TO_NO_BRKTS_FREEMAIL X-Spam-Check-By: sourceware.org Received: from mailout-de.gmx.net (HELO mailout-de.gmx.net) (213.165.64.23) by sourceware.org (qpsmtpd/0.43rc1) with SMTP; Thu, 17 Feb 2011 09:44:48 +0000 Received: (qmail invoked by alias); 17 Feb 2011 09:44:45 -0000 Received: from LN-mac29.grenoble.cnrs.fr (EHLO axel) [147.173.67.29] by mail.gmx.net (mp007) with SMTP; 17 Feb 2011 10:44:45 +0100 Date: Thu, 17 Feb 2011 10:36:00 -0000 From: Axel Freyn To: gcc-help@gcc.gnu.org Subject: Re: infinite for-loop and related question Message-ID: <20110217094436.GQ5274@axel> Mail-Followup-To: gcc-help@gcc.gnu.org References: <4D5C437F.5080207@cds1.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4D5C437F.5080207@cds1.net> User-Agent: Mutt/1.5.18 (2008-05-17) X-IsSubscribed: yes Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org X-SW-Source: 2011-02/txt/msg00253.txt.bz2 On Wed, Feb 16, 2011 at 01:37:03PM -0800, Bob Plantz wrote: > On 02/16/2011 12:41 PM, Jason Mancini wrote: >> Though I still find the output of this odd: >> >> for (char i(1); i>0; ++i) >> printf("%d %d\n", i, sizeof(i)); >> >> ... >> 362195 1 >> 362196 1 >> 362197 1 >> ... >> >> For very large values of char! ^_^ >> >> Jason > That's odd. With g++ 4.4.5 on an x86-64 machine in 64-bit mode I get: > > --- > 125 1 > 126 1 > 127 1 But there is also a second "bug" in the program. You tell "printf", that the variable "i" is a integer and not a char -- so printf will read sizeof(int) Bytes at the adress of "i" in order to create the output-number, which gives you the 362195. You should write something like printf("%d %d\n", (int)i, sizeof(i)); in order to get the "true" value of i in the output -- then I would expect values in the "char"-range -127