From owner-freebsd-chat Thu Aug 10 11:47:56 2000 Delivered-To: freebsd-chat@freebsd.org Received: from mail.ptd.net (mail2.ha-net.ptd.net [207.44.96.66]) by hub.freebsd.org (Postfix) with SMTP id 7334637B9EE for ; Thu, 10 Aug 2000 11:47:53 -0700 (PDT) (envelope-from tms2@mail.ptd.net) Received: (qmail 9469 invoked from network); 10 Aug 2000 18:47:56 -0000 Received: from du159.cli.ptd.net (HELO mail.ptd.net) (204.186.33.159) by mail.ptd.net with SMTP; 10 Aug 2000 18:47:56 -0000 Message-ID: <3992F8C5.6ABC6EC6@mail.ptd.net> Date: Thu, 10 Aug 2000 14:47:33 -0400 From: "Thomas M. Sommers" Organization: None X-Mailer: Mozilla 4.72 [en] (X11; I; FreeBSD 4.0-RELEASE i386) X-Accept-Language: en MIME-Version: 1.0 To: Anatoly Vorobey Cc: chat@freebsd.org Subject: Re: C time functions - problem References: <20000808201807.H250@parish> <20000808122832.I4854@fw.wintelcom.net> <39908B06.D1238928@mail.ptd.net> <20000809150804.L4854@fw.wintelcom.net> <39923E04.94A1B30E@mail.ptd.net> <20000810191221.A12280@happy.checkpoint.com> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-chat@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org Anatoly Vorobey wrote: > > On Thu, Aug 10, 2000 at 01:30:44AM -0400, Thomas M. Sommers wrote: > > According to the (draft) standard, section 6.3.2.3: > > > > "An integer constant expression with the value 0, or such an expression > > cast to type void *, is called a null pointer constant. If a null > > pointer constant is converted to a pointer type, the resulting pointer, > > called a null pointer, is guaranteed to compare unequal to a pointer to > > any object or function." > > > > There are very few circumstances in which you need to cast 0 to make it > > a null pointer constant. > > I am not aware of any such circumstances at all. 0 can always be used > instead of NULL, and, since I find it completely unambiguous, I always > use 0 for null pointers. > > About the only time you need to cast 0 is when you pass it to > a variable-parameters function as one of the free parameters. However, > in that case, you need to cast BOTH 0 and NULL. There's no difference. That is the circumstance I was referring to. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message