Took me about an hour to find code that has different output with and without that line... But it was fun;), so I won't spoil... 

$foo='hello';
for(1..5){
    $foo=~/(?=(.))/g;
    pos($foo)=pos($foo);
    print $1
}

[download]

"The additional state of being matched with zero-length is associated with the matched string, and is reset by each assignment to pos()."

In reply to Re^2: Your favourite gory detail... by Ido
in thread Your favourite gory detail... by Ido

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