Swift: get number of values in an enum? Goal is to avoid hard coding number in random function

Question

Given the code below, is it possible in Swift to programmatically determine the number of values inside an enum? The goal is to avoid hard coding a number in order to randomly choose a type of this enum.

enum Direction: Int {
    case North
    case East
    case South
    case West
    case Northeast
    case Southeast
    case Southwest
    case Northwest

    static func random() -> Direction {
        return Direction(rawValue: Int(arc4random_uniform(8)) + 1)!
    }
}