Ok, here is what I think is happening (according to the examples above): 
$y = 42;
$x = $y;

substr( $string, 2, 6 ) = '';
$result = substr( $string, 2, 6 );

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The other ways of writing it, $x = $y = 42; and your example are just shorthand ways.

And perldoc specifically mentions the way when you use a fourth argument instead as an alternative where you can get the replaced values back, unlike the assignment way.

You have moved into a dark place.
It is pitch black. You are likely to be eaten by a grue.

In reply to Re: Re: Re: Bug with substring return value? by Dog and Pony
in thread Bug with substring return value? by shotgunefx

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