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

You've hit a problem with Swift's generics that can't be solved the way you like it right now (maybe in a future Swift version). See also Swift Generics issue.

Currently, you'll need to define a function (for example at the global scope):

func isSorted(array: Array) -> Bool {
    for i in 1.. array[i] {
            return false
        }
    }

    return true
}

let i = [1, 2, 3]
let j = [2, 1, 3]
let k = [UIView(), UIView()]
println(isSorted(i)) // Prints "true"
println(isSorted(j)) // Prints "false"
println(isSorted(k)) // Error: Missing argument for parameter #2 in call

The error message is misleading, IMHO, as the actual error is something like "UIView doesn't satisfy the type constraint Comparable".