1 package Main

     2 

     3 class Stack[T] {

     4   var elems: List[T] = Nil

     5   def push(x: T) { elems = x :: elems }

     6   def top: T = elems.head

     7   def pop() { elems = elems.tail }

     8 }

     9 

    10 object GenericsTest extends App{

    11   val stack = new Stack[Int]

    12   stack.push(1)

    13   stack.push('a')

    14   println(stack.top)

    15   stack.pop()

    16   println(stack.top)

    17 }