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From: lcc.jbrown@LOCUS.UCLA.EDU (Jordan Brown)
Newsgroups: net.unix
Subject: if (pointer) command
Message-ID: <3651@brl-smoke.ARPA>
Date: Mon, 8-Sep-86 21:40:30 EDT
Article-I.D.: brl-smok.3651
Posted: Mon Sep  8 21:40:30 1986
Date-Received: Tue, 9-Sep-86 06:27:09 EDT
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> From: Brandon Allbery <allbery%ncoast.uucp@BRL.ARPA>
> [ code which used "if(pointer) stmt;" ]

> But if a pointer is 4 bits and an int is 2 bits (some 68000 implementations),
> you'll get spurious failures if the pointer returned by malloc is a multiple
> of 0x10000!

Those are the smallest pointers and ints I've ever seen!  But seriously,
K&R never says that the expression in an if is converted to an int.
It says (pg 201)
	...the expression is evaluated and it if is non-zero...
While this does not explicitly allow the if(pointer) usage, it can easily
be interpreted to mean that "if(expr)" is equivalent to "if(expr!=0)", which
IS guaranteed to work for pointers (pg 190).

Lots of code would break if this usage was not allowed.