The type of element returned by next().
typealias Element = (offset: Int, element: Base.Element)func next() -> EnumeratedSequence<Base>.Iterator.Element? Advances to the next element and returns it, or nil if no next element exists.
import Swift@frozen struct IteratorThe iterator for EnumeratedSequence.
@frozen struct EnumeratedSequence<Base> where Base : SequenceAn enumeration of the elements of a sequence or collection.
@frozen struct IntA signed integer value type.
associatedtype Element where Self.Element == Self.Iterator.ElementA type representing the sequence’s elements.
mutating func next() -> EnumeratedSequence<Base>.Iterator.Element? Advances to the next element and returns it, or nil if no next element exists.