RX實現.jpg

.rx的實現原理
關聯類型。
主要實現ReactiveCompatible協議，實現了這個協議的都會有rx。萬物皆rx

/// Extend NSObject with `rx` proxy.
extension ReactiveCompatible {
    /// Reactive extensions.
    public static var rx: Reactive<Self>.Type {
        get {
            return Reactive<Self>.self
        }
        set {
            // this enables using Reactive to "mutate" base type
        }
    }

    /// Reactive extensions.
    public var rx: Reactive<Self> {
        get {
            return Reactive(self)
        }
        set {
            // this enables using Reactive to "mutate" base object
        }
    }
}

extension NSObject: ReactiveCompatible { }