This declaration has been renamed to FlattenCollection.Index.
This declaration was obsoleted in Swift 5.0.
typealias FlattenCollectionIndex<T> = FlattenCollection<T>.Index where T : Collection, T.Element : Collectionimport Swifttypealias FlattenCollection<T> = FlattenSequence<T> where T : Collection, T.Element : Collection@frozen struct IndexA position in a FlattenCollection
protocol Collection<Element> : SequenceA sequence whose elements can be traversed multiple times, nondestructively, and accessed by an indexed subscript.
associatedtype Element where Self.Element == Self.Iterator.ElementA type representing the sequence’s elements.