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From: jas@postgres.uucp (James Shankland)
Newsgroups: comp.lang.c
Subject: Re: Abandon NULL for (0)
Message-ID: <17505@pasteur.Berkeley.EDU>
Date: 22 Sep 89 04:35:03 GMT
References: <6502@ux.cs.man.ac.uk> <14718@bfmny0.UU.NET> <146@bbxsda.UUCP>
Sender: news@pasteur.Berkeley.EDU
Reply-To: jas@postgres.berkeley.edu (Jim Shankland)
Organization: The Eddie Group
Lines: 28

In article <146@bbxsda.UUCP> scott@bbxsda.UUCP (Scott Amspoker) writes:
>Professionally, I cast everything - makes lint real happy.

Actually, in most cases, lint couldn't care less.  It is a fallacy that
the degree of portability of your code varies directly with the number
of casts in it.  Casts are conversions whose semantics are, in many
cases, implementation-dependent.

>At home I use 0 for a null pointer.  I test pointers with expressions
>like:
>       if (pointer)...			/* at home */
>       if (!pointer)...

Stylistically a little dubious, in my opinion, but certainly widely
practiced.  Also entirely safe.

>as opposed to
>
>       if (pointer!=(char *)0)		/* at work */
>
>Modern C compilers are quite reliable about this ...

Modern C compilers will reliably generate warnings on this if `pointer'
has any type other than `char *'.  Modern C compilers will be
entirely happy if you leave out the cast, provided `pointer' is any
scalar or pointer type.

jas