/*
下界 >:
去公安部们身份证,儿子的身份证父亲当然可以拿走
*/
class Farther(val name:String)
class Child(name:String) extends Farther(name:String)
object GetIDCard {
def getIdCard[R >: Child](person:R): Unit ={
println("you can take ID card" )
}
def main(args: Array[String]): Unit = {
getIdCard[Child](new Child("child"))
getIdCard[Farther](new Farther("farther"))
}
}