swift如何打印对象的地址

//
//  ViewController.swift
//  SwiftDemo
//
//  Created by YouXianMing on 15/10/14.
//  Copyright © 2015年 YouXianMing. All rights reserved.
//

import UIKit

class ViewController: UIViewController {
    
    var model : Model!
    
    override func viewDidLoad() {
        
        super.viewDidLoad()
        
        model = Model()
        if let tmpModel = model {
            
            print(unsafeAddressOf(tmpModel))
            print(unsafeAddressOf(model))
        }

        let tmpModel = model
        print(unsafeAddressOf(tmpModel))
    }
}

//
//  Model.swift
//  SwiftDemo
//
//  Created by YouXianMing on 15/10/14.
//  Copyright © 2015年 YouXianMing. All rights reserved.
//

import UIKit

class Model: NSObject {

}