Object pool in swift

Pool.swift

//
//  Pool.swift
//  @richy486
//
//  Created by Richard Adem on 8/02/2016.
//  Copyright © 2016 Richard Adem. All rights reserved.
//

import Foundation

class Pool<T: Hashable> {
    var unusedPool = Array<T>()
    var usingPool = Array<T>()
    
    var factoryFunction: () -> T
    
    required init(factoryFunction: () -> T) {
        self.factoryFunction = factoryFunction;
    }
    
    func getItem() -> T {
        var item: T
        if unusedPool.count > 0 {
            item = unusedPool.removeAtIndex(0)
            
        } else {
            item = factoryFunction()
            
        }
        
        usingPool.append(item)
        
        return item
    }
    
    func returnItem(item: T) {
        usingPool.removeObject(item)
        unusedPool.append(item)
    }
}