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From: edw@ius2.cs.cmu.edu (Eddie Wyatt)
Newsgroups: comp.lang.c,news.software.b
Subject: Re: passing NULL to functions
Message-ID: <1144@ius2.cs.cmu.edu>
Date: Tue, 5-May-87 21:27:58 EDT
Article-I.D.: ius2.1144
Posted: Tue May  5 21:27:58 1987
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  Someone suggested that the 'type' argument to the macro definition

	#define alloc(type)	((type *) malloc(sizeof(type)))

should have parentheses around it.  Well consider the macro expansion of

	x = alloc(int *);

Currently the expansion is

	x = ((int * *) malloc(sizeof(int *)));

If the 'type' argument is parenthesized then it would expand to

	x = (((int *) *) malloc(sizeof(int *)));

which is  syntactically incorrect (or at least the SUN compiler says it is).
Also I've added the macro definition :

	#define NULLPTR(type)	((type *) 0)

I know all of you out there will be relieved to hear that :-).

-- 
					Eddie Wyatt

e-mail: edw@ius2.cs.cmu.edu