struct JoinedByClosureCollection<Base, Separator> where Base : Collection, Separator : Collection, Base.Element : Collection, Separator.Element == Base.Element.Element
A collection that presents the elements of a base collection of collections concatenated using a given separator that depends on the collections right before and after it.
func joined<Separator>(by separator: @escaping (Element, Element) -> Separator) -> JoinedByClosureSequence<Elements, Separator> where Separator : Sequence, Separator.Element == Self.Element.Element
Returns the concatenation of the elements in this sequence of sequences, inserting the separator produced by the closure between each sequence.
func joined<Separator>(by separator: @escaping (Element, Element) -> Separator) -> JoinedByClosureCollection<Elements, Separator> where Separator : Collection, Separator.Element == Self.Element.Element
Returns the concatenation of the elements in this collection of collections, inserting the separator produced by the closure between each sequence.