Extending Array to check if it is sorted in Swift?

Question

I want to extend Array class so that it can know whether it is sorted (ascending) or not. I want to add a computed property called isSorted. How can I state the

Answer 1

Adaptation, a solution that will work in Swift 4

extension Array where Iterator.Element: Comparable {
    func isSorted(isOrderedBefore: (Iterator.Element, Iterator.Element) -> Bool) -> Bool  {
        for i in 1 ..< self.count {
            if isOrderedBefore(self[i], self[i-1]) {
                return false
            }
        }
        return true
    }
}