object world extends App {
  trait A { type L <: Nothing }
  trait B { type L >: Any}
  def toL(b: B)(x: Any): b.L = x
  val p: B with A = null

  // we can create a value of type Nothing
  println(toL(p)("hello"): Nothing)
  // at runtime: java.lang.ClassCastException: java.lang.String cannot be cast to scala.runtime.Nothing$

  // variation on a theme...
  def cast[T,U](x: T): U = toL(p)(x)

  println(cast[Int,String](1) + "hello")
  // at runtime: java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String

  println(cast[String,Int => Int]("hello")(1))
  // at runtime: java.lang.ClassCastException: java.lang.String cannot be cast to scala.Function1
}