Swfit 优雅的自定义方法

struct

struct XQ<T> {
    var type : T;

    init(_ type: T) {
        self.type = type
    }
}

extension String {
    var xq: XQ<String> {
        set {}
        get { XQ(self) }
    }
    static var xq: XQ<String>.Type {
        set {}
        get { XQ<String>.self }
    }
}

extension XQ where T: ExpressibleByStringLiteral {
    var length: Int {
        return (type as! String).count;
    }

    static func isNull(_ string: String) {
        // ...
    }
}


let len = "A".xq.length
String.xq.isNull("111")

struct

class Car { }

extension Car {
    var xq: XQ<Car> { XQ(self) }
}

extension XQ where T: Car {
    func run() {}

   mutating func stop() {}
}

Car().xq.run()

Any

extension XQ where T: Any {
    func test() {
        //...
    }
}

Car().xq.test()

let str = "2222"
str.xq.test()

思路来源《小码哥教育》