Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!nrl-cmf!ames!oliveb!felix!dhw68k!arcturus!evil
From: evil@arcturus.UUCP (Wade Guthrie)
Newsgroups: comp.lang.c
Subject: Re: Do you have to cast void pointers when dereferencing them?
Keywords: (With ANSI C)
Message-ID: <3078@arcturus>
Date: 19 Dec 88 16:50:41 GMT
References: <2414@ssc-vax.UUCP> <15012@mimsy.UUCP> <3050@arcturus> <749@auspex.UUCP>
Organization: Rockwell International, Anaheim, CA
Lines: 30

In article <749@auspex.UUCP>, guy@auspex.UUCP (Guy Harris) writes:

> Originally (well not ORIGINALLY. . .) I said:
>  >code must know the type of the lvalue to put the rvalue into the proper
>  >representation.  Is this not true?
> . . .Why is this any different from
> 	int foo; float bar; bar = foo;
> which also causes an implicit conversion from "int" to "float"?

The statement I made was regarding implicit conversion between pointer
types.  Well, as far as K&R goes, no implicit pointer type conversion
is made (they do describe how ints can be converted to float (actually
double, but I digress)).  This, I believe, is the root of some of the 
discussion lately that the following is non-portable:

	#define NULL (char *)0
	. . .
	int *foo;

	foo = NULL;

(note that different pointer types are on either side of the '=').


Wade Guthrie
Rockwell International
Anaheim, CA

(Rockwell doesn't necessarily believe / stand by what I'm saying; how could
they when *I* don't even know what I'm talking about???)