(function() {
    //  泛型：先用字符去指代未知类型 使用时在传入具体的类型
    // function fn1<T>(name:T):T {
    //     return name;
    // }
    // fn1(12);
    // fn1('22');

    function fn1<T,W>(name:T,x:W):[T,W] {
        return [name,x];
    }
    fn1(12,12);
    fn1('22','ss');

    interface happy {
        jump:string
    }
    function fn3<T extends happy>(a:T):T {
        return a;
    }
    fn3({jump:'1212'})

    class Ending<T extends happy> {
        name:T;
        constructor(name:T) {
            this.name = name;
        }
    }

    let e = new Ending({jump:'1212'})
    // Omit Pick区别
})()