Path: utzoo!mnetor!uunet!wyse!wyse.wyse.com!mikew
From: mikew@wyse.wyse.com
Newsgroups: comp.lang.c
Subject: Re: A different view of volatile
Message-ID: <178@wyse.wyse.com>
Date: 4 May 88 01:03:24 GMT
Sender: mikew@wyse.wyse.com
Reply-To: mikew@wyse.wyse.com ()
Organization: Wyse Technology
Lines: 21

It seems that volatile is ill-defined when combined with operators
that operate in-place.  A way of alleviating this problem would
be to state that conforming programs can't have a volatile variable
that is on boths sides of an equal sign,  volatile variables can't
be used on the left hand side of the following 
operators: +=, -=, *=, /=, |=, &=, and volatiles can't be used at all
with the following operators: ++, --.

Example:
...
volatile int a,b;
int c;

a=a;		/* illegal */
a=b;		/* legal */
a=c;		/* legal */
c=a;		/* legal */
a=a+c;		/* illegal */
a+=c;		/* illegal */
++a;		/* illegal */
...