signature MagicNumber = sig
  val n : int
end

functor Exiter(N : MagicNumber) = struct
  fun exit _ = __builtin "exit" N.n
end

structure FourtyTwo = struct
  val a = 16
  val n = 42
  val z = 38
end

structure FourtyTwoExiter = Exiter(FourtyTwo)

val _ = FourtyTwoExiter.exit ()