From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 11660 invoked by alias); 4 Jan 2003 23:32:15 -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 11653 invoked from network); 4 Jan 2003 23:32:15 -0000 Received: from unknown (HELO rockridge.uits.indiana.edu) (129.79.1.74) by 209.249.29.67 with SMTP; 4 Jan 2003 23:32:15 -0000 Received: from fontz.uits.indiana.edu (fontz.uits.indiana.edu [129.79.1.76]) by rockridge.uits.indiana.edu (8.12.1/8.12.1/IUPO) with ESMTP id h04NW1e3004174; Sat, 4 Jan 2003 18:32:01 -0500 (EST) Received: from locke.free-expression.org (dial-123-98.dial.indiana.edu [156.56.123.98]) by fontz.uits.indiana.edu (8.12.1/8.12.1/IUPO) with SMTP id h04NVwQt010728; Sat, 4 Jan 2003 18:32:00 -0500 (EST) Content-Type: text/plain; charset="iso-8859-1" From: Lynn Winebarger To: dewar@gnat.com (Robert Dewar), dewar@gnat.com, gmariani@chaincast.com Subject: Re: c++ "with" keyword Date: Sat, 04 Jan 2003 23:36:00 -0000 Cc: gcc@gcc.gnu.org References: <20030104223552.724F0F28C4@nile.gnat.com> In-Reply-To: <20030104223552.724F0F28C4@nile.gnat.com> MIME-Version: 1.0 Message-Id: <03010418240300.01603@locke.free-expression.org> Content-Transfer-Encoding: 8bit X-SW-Source: 2003-01/txt/msg00174.txt.bz2 On Saturday 04 January 2003 17:35, Robert Dewar wrote: > > Any language construct that fails in this regard (like with) is very bad > > - period. > > But look carefully at what you are saying. We are talking about a structure > or class whose members are visible to the client of the library. The change > we are talking about is adding a new member to the structure. You cannot > possibly think that such a change can be done in a guaranteed 100% > upwards compatible manner. That's absurd. > > (for example, at the very least the size of an instance will change). > > Furthermore, the situations under which adding this member will cause > specifically a difficulty with WITH are very marginal. It is indeed > far more likely that the addition of a member will cause other compatibility > differences. Why not just make it possible to specify exactly what identifiers you want to import from the class of the variable (ala Perl's use mechanism)? Lynn