struct Zip2Iterator<Iterator1 : IteratorProtocol, Iterator2 : IteratorProtocol> An iterator for Zip2Sequence. Inheritance IteratorProtocol View Protocol Hierarchy → Associated Types Element = (Iterator1.Element, Iterator2.Element) The type of element returned by next(). Import import Swift Instance Methods mutating func next() Advances to the next element and returns it, or nil if no next element exists. Once nil has been returned, all subsequent calls return nil. Declaration mutating func next() -> (Iterator1.Element, Iterator2.Element)?