测试方法在类型上不可用的方法

trait Game
trait BlackToPlay extends Game {
  def move(p: BlackPiece,s: Square): Either[FinishedGame,WhiteToPlay]
}
trait WhiteToPlay extends Game {
  def move(p: WhitePiece,BlackToPlay]
}

我可以在不诉诸反思的情况下做出以下重要断言吗？

"A game with white to play" should {
  "not allow black to play" in {
    // an instance of whiteToPlay should not 
    // have the `move(BlackPiece,Square)` method.
  }
}

编辑：我尝试实施@Martin的解决方案不起作用.对这里有什么不妥的想法？来自REPL：

scala> class B() {
     |   def b(s: String) = s
     | }
defined class B

scala> val b = new B()
b: B = B@420e44

scala> b.c("")
<console>:8: error: value c is not a member of B
       b.c("")
         ^

scala> b match {
     |   case _: { def c(s: String) } => false
     |   case _ => true
     | }
warning: there were unchecked warnings; re-run with -unchecked for details
res7: Boolean = false

res7应该是true,因为b不应该匹配{def c(s：String)}的结构类型