RLMResults' does not have a member named 'Generator

http://qiita.com/jtemplej/items/1c1b7204341ac01e561e

上記のサイトを参考にRealmを使い始めたのですが、for realmBook in Book.allObjects()の行で'RLMResults' does not have a member named 'Generator'というエラーが表示されます。何か初歩的なことが間違っているような気がするのですが、どこが間違っているのでしょうか？下記に現在のコードを記しますので、どなたか分かる方がいれば教えていただきたいです。すみませんが、よろしくお願いします。

Book.swift

import Foundation
import Realm

class Book : RLMObject {
    dynamic var isbn = ""
    dynamic var name = ""
    dynamic var price = 0
}

ViewController.swift

import UIKit
import Realm

class ViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        stockData()
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func stockData() {
        let realm = RLMRealm.defaultRealm()

        // Bookオブジェクト生成.
        let book = Book()
        book.isbn = "999999"
        book.name = "realm sample"
        book.price = 100

        // Bookオブジェクトを保存.
        realm.beginWriteTransaction()
        realm.addObject(book)
        realm.commitWriteTransaction()

        // 先ほどのBookオブジェクトを取得
        // Class.allObjectsで全オブジェクト取得.
        for realmBook in Book.allObjects() {
            // book name:realm sample
            println("book name:\((realmBook as Book).name)")
        }

        let book2 = Book()
        book2.isbn = "999998"
        book2.name = "realm tutorial 1"
        book2.price = 1000

        // Blockでの保存の仕方.
        realm.transactionWithBlock() {
            realm.addObject(book2)
        }

        for realmBook in Book.allObjects() {
            // book name:realm sample
            // book name:realm tutorial 1
            println("book name:\((realmBook as Book).name)")
        }
    }
}