= Solution
For the implementations above the value is
``
List('1', '3', '5', '7', '9')
``
The first half-<iterator> returns the odd-position characters while consuming the even-position characters as its required skips. By the time it is exhausted, it has consumed the entire shared underlying <iterator>. The second half-<iterator> consequently has no entries left when concatenation reaches it. \b[Sharing one source does not create two independent traversals.] Neither constructor consumes anything, so it also does not shift the first output before iteration begins. The source's implementation references here should be read as parts (d) and (e); the printed reference to (c) and (d) is a cross-reference slip.
Back to article page
