Convert generic free function into Array extension

Question

I wrote some code to perform run length encoding and decoding. I have my encoding function as a method in an extension to Array, but I can\'t make the decoding in a similar

Answer 1

Instead of constraining the array extension move the constraint to your method:

extension Array {
    func runLengthDecode<T: Equatable>() -> [T] where Element == (element: T, count: Int)  {
        return flatMap{ repeatElement($0.element, count: $0.count) }
    }
}

or simply

extension Array {
    func runLengthDecode<T: Equatable>() -> [T] where Element == (element: T, count: Int)  {
        return flatMap(repeatElement)
    }
}