Populate a new array.

Here's another one:

I've created a method that returns an array of its own class:

anArray: aQuantity
        | a |
        a := Array new: aQuantity.
        a size
                do: [:i | a at: i put: self class new].
        ^ a

but, for a while, I was trying to make this a single line:

^ (Array new: aQuantity) do: [:item | item := stuff ]

This doesn't work (I think) because "do" passes in a value rather than a  
reference. I didn't see how it could be done with withIndexDo: either.

Wondering if I'm missing something.

Also, observing that "at:" is actually implemented in Object, which  
seems...odd!