Date: Thu, 10 Aug 2000 19:12:21 +0300 From: Anatoly Vorobey <mellon@pobox.com> To: "Thomas M. Sommers" <tms2@mail.ptd.net> Cc: chat@freebsd.org Subject: Re: C time functions - problem Message-ID: <20000810191221.A12280@happy.checkpoint.com> In-Reply-To: <39923E04.94A1B30E@mail.ptd.net>; from tms2@mail.ptd.net on Thu, Aug 10, 2000 at 01:30:44AM -0400 References: <20000808201807.H250@parish> <20000808122832.I4854@fw.wintelcom.net> <39908B06.D1238928@mail.ptd.net> <20000809150804.L4854@fw.wintelcom.net> <39923E04.94A1B30E@mail.ptd.net>
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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. -- Anatoly Vorobey, mellon@pobox.com http://pobox.com/~mellon/ "Angels can fly because they take themselves lightly" - G.K.Chesterton To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-chat" in the body of the message
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