unchecked3.scala:24: warning: non-variable type argument Double in type pattern E1[Double] is unchecked since it is eliminated by erasure
  /*   warn */ def peerTypes2(x: B1[Int]) = x match { case _: E1[Double] => true }
                                                              ^
unchecked3.scala:25: warning: non-variable type argument Double in type pattern F1[Double] is unchecked since it is eliminated by erasure
  /*   warn */ def peerTypes3(x: B1[_]) = x match { case _: F1[Double] => true }
                                                            ^
unchecked3.scala:28: warning: non-variable type argument Int in type pattern A2[Int] is unchecked since it is eliminated by erasure
  /*   warn */ def twotypes1[T](x: B2[T, Int]) = x match { case _: A2[Int] => true }
                                                                   ^
unchecked3.scala:32: warning: non-variable type argument Int in type pattern B2[_,Int] is unchecked since it is eliminated by erasure
  /*   warn */ def twotypes5[T](x: A2[T]) = x match { case _: B2[_, Int] => true }
                                                              ^
unchecked3.scala:40: warning: non-variable type argument String in type pattern Array[List[String]] is unchecked since it is eliminated by erasure
    /*   warn */ case _: Array[List[String]]         => ()
                         ^
unchecked3.scala:43: warning: non-variable type argument String in type pattern Array[Array[List[String]]] is unchecked since it is eliminated by erasure
    /*   warn */ case _: Array[Array[List[String]]]  => ()
                         ^
unchecked3.scala:50: warning: non-variable type argument String in type pattern Array[List[String]] is unchecked since it is eliminated by erasure
    /*   warn */ case _: Array[List[String]]         => ()
                         ^
unchecked3.scala:53: warning: non-variable type argument String in type pattern Array[Array[List[String]]] is unchecked since it is eliminated by erasure
    /*   warn */ case _: Array[Array[List[String]]]  => ()
                         ^
unchecked3.scala:60: warning: non-variable type argument String in type pattern Array[List[String]] is unchecked since it is eliminated by erasure
    /*   warn */ case _: Array[List[String]]        => ()
                         ^
unchecked3.scala:62: warning: non-variable type argument Array[String] in type pattern Array[List[Array[String]]] is unchecked since it is eliminated by erasure
    /*   warn */ case _: Array[List[Array[String]]] => ()
                         ^
unchecked3.scala:63: warning: non-variable type argument String in type pattern Array[Array[List[String]]] is unchecked since it is eliminated by erasure
    /*   warn */ case _: Array[Array[List[String]]] => ()
                         ^
unchecked3.scala:75: warning: abstract type A in type pattern scala.collection.immutable.Set[Q.this.A] (the underlying of Set[Q.this.A]) is unchecked since it is eliminated by erasure
      /*   warn */ case xs: Set[A]  => xs.head
                            ^
unchecked3.scala:62: warning: unreachable code
    /*   warn */ case _: Array[List[Array[String]]] => ()
                                                       ^
error: No warnings can be incurred under -Xfatal-warnings.
13 warnings found
one error found