ZMapTable.swift

// ZMapTable.swift
//
// Copyright (c) 2016 Kaz Yoshikawa. Released under MIT License.

enum ZMapTableOption {
	case StrongToWeak
	case WeakToStrong
	case WeakToWeak
	case StrongToStrong
}

class ZMapTable<K: AnyObject, V: AnyObject>: CustomStringConvertible {

	let mapTable: NSMapTable

	init(option: ZMapTableOption) {
		switch option {
		case .StrongToWeak: self.mapTable = NSMapTable.strongToWeakObjectsMapTable()
		case .WeakToStrong: self.mapTable = NSMapTable.weakToStrongObjectsMapTable()
		case .WeakToWeak: self.mapTable = NSMapTable.weakToWeakObjectsMapTable()
		case .StrongToStrong: self.mapTable = NSMapTable.strongToStrongObjectsMapTable()
		}
	}

	subscript(key: K) -> V? {
		get { return self.mapTable.objectForKey(key) as? V }
		set { self.mapTable.setObject(newValue, forKey: key) }
	}
	
	var description: String {
		return self.mapTable.description
	}

}