Xref: utzoo comp.os.os9:220 comp.lang.c:13600
Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!ukma!nrl-cmf!cmcl2!adm!smoke!gwyn
From: gwyn@smoke.BRL.MIL (Doug Gwyn )
Newsgroups: comp.os.os9,comp.lang.c
Subject: Re: Bugs in OS9/68K C-Compiler ?
Message-ID: <8782@smoke.BRL.MIL>
Date: 28 Oct 88 00:31:33 GMT
References: <147@fbihh.UUCP> <636@tuvie>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 15

In article <636@tuvie> rzmul3@tuvie (Uni Leoben) writes:
>For the 'return 0 != ptr' problem : I don't know why, but 'return ptr != 0'
>works. Apparently the compiler automatically casts integers to pointers
>on comparisons but doesn't cast pointers to integers.

That certainly is a confused compiler.  != is a symmetric operator.

It is not a matter of a cast (do YOU see a cast?) nor even of a type
conversion.  Any pointer may be compared for (in)equality with a null
pointer, and 0 is one way to write a null pointer constant (in ANSI C,
(void*)0 is another).  I think most programmers would find
	return ptr != 0;
clearer than
	return 0 != ptr;
but these are technically equivalent.