From mboxrd@z Thu Jan  1 00:00:00 1970
From: Richard Earnshaw <rearnsha@arm.com>
To: Nathan Sidwell <nathan@cs.bris.ac.uk>
Cc: rearnsha@sun52.arm.com
Subject: Re: suggest parentheses around assignment used as truth value 
Date: Fri, 03 Jul 1998 06:15:00 -0000
Message-id: <199807030923.KAA25571@sun52.NIS.cambridge>
References: <359C95DD.40B0@cs.bris.ac.uk>
X-SW-Source: 1998-07/msg00141.html

> 
> It's rather hard to double the parentheses in error, and the form does
> visually stand out.
> 

It's very easy to double the parentheses in error.  You just have to have 
the erroneous code inside a macro.

Somewhat simple I know, but:

#define COMPARE(X,Y) ((X)=(Y)) /* Should be == */

...

if (COMPARE(p,q)) {...}  /* Should get a warning, but doesn't */

Richard.