Fast array behavior

Question

Swift arrays have a special behavior, but why does arr1 contain two times “element 1”, while arr2 contains it only once?

What defines arr1 as an instance variable here (as opposed to defining arr2 as a local variable)?

Update: I am using Xcode 6.0.1

Answer 1

I can reliably reproduce this result in Xcode 6.0.1:

But not in Xcode 6.1 GM:

It seems that a bug has been fixed.

As a temporary workaround, this works in Xcode 6.0.1: