Binding+Collection.swift

extension Binding: Sequence where Value == Array<Track> {
    public typealias Iterator = IndexingIterator<Array<Binding<Track>>>

    public __consuming func makeIterator() -> IndexingIterator<Array<Binding<Track>>> {
        return IndexingIterator(_elements: (0..<wrappedValue.count).map { projectedValue[$0] })
    }
}

extension Binding: Collection where Value == Array<Track> {
    public typealias Element = Binding<Track>
    public typealias Index = Value.Index

    public var startIndex: Array<Track>.Index {
        return wrappedValue.startIndex
    }

    public var endIndex: Array<Track>.Index {
        return wrappedValue.endIndex
    }

    public func index(after i: Array<Track>.Index) -> Array<Track>.Index {
        return wrappedValue.index(after: i)
    }

    public subscript(position: Array<Track>.Index) -> Binding<Track> {
        return projectedValue[position]
    }
}

extension Binding: BidirectionalCollection where Value == Array<Track> {
    public func index(before i: Array<Track>.Index) -> Array<Track>.Index {
        return wrappedValue.index(before: i)
    }
}

extension Binding: RandomAccessCollection where Value == Array<Track> { }