Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!elroy.jpl.nasa.gov!ames!dftsrv!mimsy!chris
From: chris@mimsy.umd.edu (Chris Torek)
Newsgroups: comp.lang.c
Subject: Re: void * compatibility
Keywords: C void types
Message-ID: <26628@mimsy.umd.edu>
Date: 20 Sep 90 01:19:00 GMT
References: <8770@b11.ingr.com>
Distribution: usa
Organization: U of Maryland, Dept. of Computer Science, Coll. Pk., MD 20742
Lines: 17

In article <8770@b11.ingr.com> polfer@b11.ingr.com (? Polfer) writes:
>... "Type `void *' is not assignment compatible with type `int (*)()'."
>The compiler is not in full ANSI mode ... [and] Metaware High C
>defines NULL in stdio.h as "(void *)0".

The value ((void *)0) is a generic nil pointer, as well as being a
particular specific nil pointer, and any compiler that believes it
is not suitable in an (int (*)()) context is buggy (at least if the
compiler claims ANSI conformance).

Personally, I think defining NULL as (void *)0 is foolishness: if you
want your compiler to provide complete error checking, you should define
it as `__nil' and make __nil a keyword.  Using (void *)0 fixes a few
specific problems, but leaves others unfixed and unfixable.
-- 
In-Real-Life: Chris Torek, Univ of MD Comp Sci Dept (+1 301 405 2750)
Domain:	chris@cs.umd.edu	Path:	uunet!mimsy!chris