# 单例设计模式

/* 单例实现 */
class Singleton {
    static let sharedInstance = Singleton()
    private init() {}
}

extension Singleton : NSCopying, NSMutableCopying {
    func copy(with zone: NSZone? = nil) -> Any {
        return Singleton.sharedInstance
    }
    
    func mutableCopy(with zone: NSZone? = nil) -> Any {
        return Singleton.sharedInstance
    }
}

// 单例访问方式
Singleton.sharedInstance

参考学习内容

• Swift 开发者必备 Tips
• Design Patterns by Tutorials