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Date: Fri, 25 Jan 2002 12:07:26 +0100
From: Helge Hafting <helgehaf@aitel.hist.no>
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To: timothy.covell@ashavan.org, linux-kernel@vger.kernel.org
Subject: Re: RFC: booleans and the kernel
In-Reply-To: <Pine.LNX.4.44.0201241433110.2839-100000@waste.org> <200201242123.g0OLNAL06617@home.ashavan.org.>
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Timothy Covell wrote:
> 
> On Thursday 24 January 2002 14:39, Oliver Xymoron wrote:
> >
> > The compiler _will_ turn if(a==0) into a test of a with itself rather than
> > a comparison against a constant. Since PDP days, no doubt.
> 
> I thought that the whole point of booleans was to stop silly errors
> like
> 
> if ( x = 1 )
> {
>         printf ("\nX is true\n");
> }
> else
> {
>         # we never get here...
> }

Booleans won't help that.  If you _want_ to fix that, change
the assignment operator so it don't look like a comparison.
Perhaps x <- 45; or something.  Won't happen to C of course.

Oh, and writing if (a=b) is valid way of testing for a non-zero
b while also assigning to a.  I write code that way when I
need such a set of operation.  Short, elegant, and no, it isn't
hard to read at all.

Helge Hafting
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