From: imp@bsdimp.com (Warner Losh)
Subject: [TUHS] C question for the historians
Date: Wed, 8 Nov 2017 13:36:40 -0700 [thread overview]
Message-ID: <CANCZdfrHzwDzTBuCy5ofBqq8ZentXQP1Fjs32ZKt_99fJBsVTA@mail.gmail.com> (raw)
In-Reply-To: <20171108190540.GA7241@mcvoy.com>
On Wed, Nov 8, 2017 at 12:05 PM, Larry McVoy <lm at mcvoy.com> wrote:
> On Wed, Nov 08, 2017 at 06:14:20PM +0000, Ralph Corderoy wrote:
> > is better then why stop there? Why not
> >
> > if (((w & MASK) != FALSE) == TRUE)
>
>
> Thanks for this, that's the perfect come back to the pedantic folks.
>
It's also wrong. You couldn't flip it around to write
if (((w & MASK) == TRUE) == TRUE)
because that only works when MASK == 1. So it's dangerous since you can't
apply the normal laws of algebra on it because you are comparing BOOLEANS
and MASKS, which has always ended in pain...
Warner
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prev parent reply other threads:[~2017-11-08 20:36 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-11-08 16:17 Arthur Krewat
2017-11-08 16:27 ` Warner Losh
2017-11-09 10:17 ` Michael Kjörling
2017-11-08 18:14 ` Ralph Corderoy
2017-11-08 18:34 ` Arthur Krewat
2017-11-08 19:05 ` Larry McVoy
2017-11-08 20:13 ` ron minnich
2017-11-08 20:23 ` Larry McVoy
2017-11-08 20:32 ` Ron Natalie
2017-11-08 20:39 ` Warner Losh
2017-11-08 20:41 ` Chet Ramey
2017-11-09 1:22 ` Ralph Corderoy
2017-11-09 1:41 ` Chet Ramey
2017-11-09 1:49 ` Arthur Krewat
2017-11-08 20:43 ` Bakul Shah
2017-11-08 20:55 ` Steve Nickolas
2017-11-08 20:36 ` Warner Losh [this message]
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