t4425.scala:3: error: object X is not a case class, nor does it have an unapply/unapplySeq member
Note: def unapply(x: Int)(y: Option[Int]): None.type exists in object X, but it cannot be used as an extractor due to its second non-implicit parameter list
  42 match { case _ X _ => () }
                    ^
t4425.scala:8: error: object X is not a case class, nor does it have an unapply/unapplySeq member
Note: def unapply(x: Int)(y: Int): Some[(Int, Int)] exists in object X, but it cannot be used as an extractor due to its second non-implicit parameter list
  42 match { case _ X _ => () }
                    ^
t4425.scala:13: error: object X is not a case class, nor does it have an unapply/unapplySeq member
Note: def unapply(x: String)(y: String): Some[(Int, Int)] exists in object X, but it cannot be used as an extractor due to its second non-implicit parameter list
  "" match { case _ X _ => () }
                    ^
three errors found