Path: utzoo!utgpu!water!watmath!clyde!rutgers!husc6!cmcl2!brl-adm!brl-smoke!gwyn
From: gwyn@brl-smoke.ARPA (Doug Gwyn )
Newsgroups: comp.lang.c
Subject: Re: ! operator in constant expressions
Message-ID: <7027@brl-smoke.ARPA>
Date: 11 Jan 88 08:06:11 GMT
References: <3813@hoptoad.uucp>
Reply-To: gwyn@brl.arpa (Doug Gwyn (VLD/VMB) <gwyn>)
Organization: Ballistic Research Lab (BRL), APG, MD.
Lines: 17

In article <3813@hoptoad.uucp> gnu@hoptoad.uucp (John Gilmore) writes:
>I just wrote an interesting test program for ! and haven't yet found
>a compiler that correctly implements the draft ANSI standard for it.
>int install = !0;
>char foo = !1;

I left the draft standard in my other trousers, but I'm sure that
the above two should work, with values 1 and 0 in that order.

>int bar = !3.14156;
>int pno = ! &bar;
>int pyes = !(char *)0;

I don't see how you could expect any of these three to work; the
operand of ! has to be an integer, which might be obtained by
promotion but never by demotion or assumed type conversion of
pointers.