Pattern matching on path-dependent types

gistfile1.sbt

sealed trait A {
  type X
  case class B(x: X)

  def b: B
}

case class J(x: String) extends A {
  type X = String
  override def b = B(x)
}

case class K(x: Int) extends A {
  type X = Int
  override def b = B(x)
}

object Main {
  def main(argv: Array[String]) {
    List(J("a"), K(1)).map(_.b).foreach {
      case J#B(s) => println("String " + s)
      case K#B(i) => println("Int " + i)
    }
  }
}

This doesnt work in Scala 2.11