oh shi~

scala> case class Scalar(s: String)
scala> case class Sequence(s: Seq[String])
scala> object ScalarMatcher { def unapply(x: Scalar) = Some(x.s) }
scala> object SequenceMatcher { def unapply(x: Sequence) = Some(x.s) }

scala> Scalar("x").s match { case ScalarMatcher(x) => x ; case _ => "because fuck you" }
<console>:11: error: scrutinee is incompatible with pattern type;
 found   : Scalar
 required: String
              Scalar("x").s match { case ScalarMatcher(x) => x ; case _ => "because fuck you" }
                                                      ^

scala> Sequence(Seq("x")).s match { case SequenceMatcher(x) => x ; case _ => "because fuck you" }
res6: Object = because fuck you