Returns shuffled array

Array_extension_shuffle.swift

extension Array {
    func shuffled() -> [Element] {
        return shuffle(self)
    }
    
    func shuffle(array: [Element]) -> [Element] {
        guard array.count > 1 else { return array }
        
        var list = array
        let randomIndex = Int(arc4random_uniform(UInt32(array.count)))
        return [list.removeAtIndex(randomIndex)] + shuffle(list)
    }
}