From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261466AbVGZB3i (ORCPT ); Mon, 25 Jul 2005 21:29:38 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261482AbVGZB3i (ORCPT ); Mon, 25 Jul 2005 21:29:38 -0400 Received: from TYO201.gate.nec.co.jp ([202.32.8.214]:45961 "EHLO tyo201.gate.nec.co.jp") by vger.kernel.org with ESMTP id S261466AbVGZB3e (ORCPT ); Mon, 25 Jul 2005 21:29:34 -0400 To: Linus Torvalds Cc: Chuck Ebbert <76306.1226@compuserve.com>, linux-kernel , Andrew Morton , Vincent Hanquez , Andi Kleen Subject: Re: [patch 2.6.13-rc3] i386: clean up user_mode macros References: <200507251901_MC3-1-A589-A433@compuserve.com> From: Miles Bader Reply-To: Miles Bader System-Type: i686-pc-linux-gnu Blat: Foop Date: Tue, 26 Jul 2005 10:28:43 +0900 In-Reply-To: (Linus Torvalds's message of "Mon, 25 Jul 2005 16:13:13 -0700 (PDT)") Message-Id: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Linus Torvalds writes: > Ask a hundred random C programmers what "!!x" means, versus what "x != 0" > means, and time their replies. I've always thought of "!!" as the "canonicalize boolean" operator... Vaguely ugly, but I think it's actually _more clear_ than != 0 in contexts where the value is already "boolean" in the C zero or not-zero sense, but you want a "proper" boolean (0 or 1) for some reason. -miles -- Somebody has to do something, and it's just incredibly pathetic that it has to be us. -- Jerry Garcia