From kde-core-devel  Tue Jun 23 05:52:18 2009
From: Oswald Buddenhagen <ossi () kde ! org>
Date: Tue, 23 Jun 2009 05:52:18 +0000
To: kde-core-devel
Subject: Re: Review Request: KColorSpace::KHCY::KHCY(const & QColor)
Message-Id: <20090623055218.GA3524 () ugly ! local>
X-MARC-Message: https://marc.info/?l=kde-core-devel&m=124573635106018

On Mon, Jun 22, 2009 at 07:15:39PM -0400, Michael Pyne wrote:
> On Monday 22 June 2009 17:53:54 Michael Kreitzer wrote:
> > I considered that as well. The only thing that worries me is IEEE 754 on
> > x86 seems woefully unreliable for direct comparisons if you're not trying
> > to do something very simple (e.g. prevent a divide by zero).
> 
> In all fairness, floating point on pretty much any platform is not suitable 
> for comparing to equality with anything but 0.0.  For floating point if you 
> must compare something being equal to another value you should allow some 
> tolerance (i.e. is it within 1e-5, not is it exactly equal to something).

> I think the best answer in this case is to ensure as much as possible, 
> comparisons are done against 0.0 (i.e. don't do if (a == b), but do c = a - b; 
> if(c == 0.0) )
> 
i really have to wonder what the technical foundation of that idea is,
because to me it doesn't make any sense.