t7285.scala:15: warning: match may not be exhaustive.
It would fail on the following input: (Up, Down)
      (d1, d2) match {
      ^
t7285.scala:33: warning: match may not be exhaustive.
It would fail on the following input: Down
      (d1) match {
       ^
t7285.scala:51: warning: match may not be exhaustive.
It would fail on the following input: (Up, Down)
    (d1, d2) match {
    ^
error: No warnings can be incurred under -Xfatal-warnings.
three warnings found
one error found