I honestly don't see the point, but then maybe that's because literally none of the code I write uses a callback to multiply a number by 2.<p>I've seen similar "look how minimal a closure can be" arguments for several languages, and they <i>always</i> use a ridiculously simple body - usually `$x * $y` or `$x * 2` etc.<p>How do they end up looking (and thus how easy are they to read) when its a realistic body with several lines?