无法确定StrangeIntQueue扩展队列有什么问题,为什么会出现错误“构造器队列的参数不足:(leading:Int)list.Lister.Queue [Int]。Unspecified value parameter leading” 。我怎样才能指定它?Scala编译错误
class Queue[+T](
private val leading: T
) {
def enqueue[U >: T](x: U) =
new Queue[U](leading: U) // ...
}
class StrangeIntQueue(private val leading: Int) extends Queue[Int] {
override def enqueue(x: Int) = {
println(math.sqrt(x))
super.enqueue(x)
}
}