From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 27281 invoked by alias); 23 Nov 2004 16:44:38 -0000 Mailing-List: contact gcc-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Archive: List-Post: List-Help: Sender: gcc-owner@gcc.gnu.org Received: (qmail 27245 invoked from network); 23 Nov 2004 16:44:34 -0000 Received: from unknown (HELO sadr.equallogic.com) (66.155.203.134) by sourceware.org with SMTP; 23 Nov 2004 16:44:34 -0000 Received: from sadr.equallogic.com (localhost.localdomain [127.0.0.1]) by sadr.equallogic.com (8.12.8/8.12.8) with ESMTP id iANGiX2B001968 for ; Tue, 23 Nov 2004 11:44:33 -0500 Received: from M30.equallogic.com (m30 [172.16.1.30]) by sadr.equallogic.com (8.12.8/8.12.8) with SMTP id iANGiXqn001963; Tue, 23 Nov 2004 11:44:33 -0500 Received: from pkoning.equallogic.com ([172.16.1.220]) by M30.equallogic.com with Microsoft SMTPSVC(5.0.2195.6713); Tue, 23 Nov 2004 11:44:33 -0500 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <16803.26864.624255.231502@gargle.gargle.HOWL> Date: Tue, 23 Nov 2004 17:01:00 -0000 From: Paul Koning To: ebotcazou@libertysurf.fr Cc: gcc@gcc.gnu.org Subject: Re: generalized lvalues -- patch outline References: <4D2CF60C-3919-11D9-8BD2-000A95BCF344@apple.com> <4D0584E2-3D61-11D9-AEB4-000A95D692F4@physics.uc.edu> <200411231728.58506.ebotcazou@libertysurf.fr> X-OriginalArrivalTime: 23 Nov 2004 16:44:33.0751 (UTC) FILETIME=[B5FAC670:01C4D17B] X-SW-Source: 2004-11/txt/msg00825.txt.bz2 >>>>> "Eric" == Eric Botcazou writes: >> The average C programmer would not have thought to use this >> extension unless they just decided one day to try it or they >> actually read the gcc documentation (which I know almost nobody >> does). Eric> I disagree: *((int *)p)++ was accepted by virtually all the Eric> good old compilers: GCC 2.x, Microsoft, Borland, Watcom. This Eric> is a natural idiom when you're manipulating images with Eric> different color depths ... ... or doing alignment-optimized copying. I've seen this notation in our code, and I'm pretty sure the author didn't get it from the GCC docs. It's a natural thing to write -- unless you ARE a language lawyer and understand the hairy details of precisely what is an lvalue and what is not. paul