Date: Tue, 04 Sep 2001 11:37:07 +0100
From: Jasper McCrea <jasper@guideguide.com>
Subject: Re: references, slices, voodoo
Message-Id: <3B94AED2.698A3CF@guideguide.com>

Walter Hafner wrote:
> 
> What I don't understand:
> 
> abigail writes:
> 
> > Note that the stupid 'unless $i == $j' no longer appears in modern
> > editions of the FAQ.
> 
> why "stupid"?
> 
> -Walter

I suppose because the test isn't much faster than the swap. Quick
benchmark showed that a swap was only 1/5 as fast as the test, so if the
array has more than twice as many elements that are different than are
the same (likely), it's a waste of time to do the test every time, when
you may as well swap.

A nice XOR swap benchmarked 1/2 as fast as a (==) test, but I suppose
it's harder to see what's going on there, so more confusion would arise.

Jasper
-- 
      split//,'019617511192'.
      '17011111610114101114'.
      '21011141011840799901'.
            '17101174';
            foreach(0..         # my
            $#_){$_[$_          # signature is too
            ++]^=$_[$_          # bignature
            --]^=$_[$_
]^=$_[++    $_]if!($_%
2)}$g.=$_  ,chr($g)=~
 /(\w)/&&($o.=$1and
   $g='')foreach@_;
      print"$o\n"