前端之家收集整理的这篇文章主要介绍了
Swift的单例模式写法，
前端之家小编觉得挺不错的，现在分享给大家，也给大家做个参考。
Approach B: Nested struct
class SingletonB {
class var sharedInstance: SingletonB {
struct Static {
static let instance: SingletonB = SingletonB()
}
return Static.instance
}
}
Approach C: dispatch_once
class SingletonC {
class var sharedInstance: SingletonC {
struct Static {
static var onceToken: dispatch_once_t = 0
static var instance: SingletonC? = nil
}
dispatch_once(&Static.onceToken) {
Static.instance = SingletonC()
}
return Static.instance!
}
}
