Type constrained class (object) version of Array that can be used as reference

ZDictionary.swift

//
//  ZDictionary.swift
//  ZKit
//
//  The MIT License (MIT)
//
//  Copyright (c) 2016 Electricwoods LLC, Kaz Yoshikawa.
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
//  WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.

import Foundation


class ZDictionary<K: Hashable, V>: CollectionType {

	typealias Element = (K, V)
	typealias Index = DictionaryIndex<K, V>
	var _dictionary: Dictionary<K, V>

	init() {
		_dictionary = Dictionary<K, V>()
	}

	func removeAll() {
		_dictionary.removeAll()
	}

	subscript (key: K) -> V? {
		get { return _dictionary[key] }
		set { _dictionary[key] = newValue }
	}

	subscript (position: Index) -> Element {
		return _dictionary[position]
	}
	var count: Int { return _dictionary.count }
	var startIndex: Index { return _dictionary.startIndex }
	var endIndex: Index { return _dictionary.endIndex }
}