Quicksort in Swift using Generics (Not in-place)

[Playground]Quicksort_caching_generics.swift

import Cocoa

func quicksort<T: Comparable>(array:T[])->T[] {
    
    var less = T[](), equal = T[](), greater = T[]()
    
    if array.count > 1{
        let pivot = array[0]
        
        for x in array{
            switch(x){
                case (let v) where v < pivot:
                    less.append(v)
                case (let v) where v > pivot:
                    greater.append(v)
                default:
                    equal.append(x)
            }
        }
        return (quicksort(less) + equal + quicksort(greater));
    }else{
        return array;
    }
}

let randomString = ["bravo","alpha","aalpha","delta","charlie"];
let sortedString = quicksort(randomString);

let randomInt = [10,30,2,15]
let sortedInt = quicksort(randomInt)