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sealed trait A2[T1]
final class B2[T1, T2] extends A2[T1]
sealed trait A[T]
final class B[T] extends A[T]
sealed trait A1[T]
trait B1[T] extends A1[T]
trait C1[T] extends A1[T]
trait D1[T] extends A1[Int]
trait E1[T] extends B1[Int]
trait F1[T] extends B1[T]
object MiscUnchecked {
/* nowarn */ def knownType1(x: A[Int]) = x match { case _: B[Int] if true => 1 }
/* nowarn */ def knownType2(x: B[Int]) = x match { case _: A[Int] if true => 1 }
/* nowarn */ def tparamLeakage1(x: Any) = x match { case Array() => 1 }
/* nowarn */ def tparamLeakage2(x: Any) = x match { case List() => 1 }
// E1[Double] implies B1[Int], but B1[Int] does not imply E1[Double], even if .isInstanceOf[E1[_]]
// F1[Int] implies B1[Int], and B1[Int] implies F1[Int]
/* nowarn */ def peerTypes1(x: B1[Int]) = x match { case _: C1[Int] => true }
/* warn */ def peerTypes2(x: B1[Int]) = x match { case _: E1[Double] => true }
/* warn */ def peerTypes3(x: B1[_]) = x match { case _: F1[Double] => true }
/* nowarn */ def peerTypes4(x: B1[Int]) = x match { case _: F1[Int] => true }
/* warn */ def twotypes1[T](x: B2[T, Int]) = x match { case _: A2[Int] => true }
/* nowarn */ def twotypes2[T](x: B2[Int, T]) = x match { case _: A2[Int] => true }
/* nowarn */ def twotypes3(x: A2[Int]) = x match { case _: B2[Int, _] => true }
/* nowarn */ def twotypes4[T](x: A2[T]) = x match { case _: B2[T, _] => true }
/* warn */ def twotypes5[T](x: A2[T]) = x match { case _: B2[_, Int] => true }
}
object Arrays {
def f1(x: Any) = x match {
/* nowarn */ case _: Array[Int] => ()
/* nowarn */ case _: Array[Boolean] => ()
/* nowarn */ case _: Array[String] => ()
/* warn */ case _: Array[List[String]] => ()
/* nowarn */ case _: Array[Array[String]] => ()
/* nowarn */ case _: Array[Array[Array[String]]] => ()
/* warn */ case _: Array[Array[List[String]]] => ()
}
def f2(x: Array[_]) = x match {
/* nowarn */ case _: Array[Int] => ()
/* nowarn */ case _: Array[Boolean] => ()
/* nowarn */ case _: Array[String] => ()
/* warn */ case _: Array[List[String]] => ()
/* nowarn */ case _: Array[Array[String]] => ()
/* nowarn */ case _: Array[Array[Array[String]]] => ()
/* warn */ case _: Array[Array[List[String]]] => ()
}
def f3[T](x: Array[T]) = x match {
/* nowarn */ case _: Array[Int] => ()
/* nowarn */ case _: Array[Boolean] => ()
/* nowarn */ case _: Array[String] => ()
/* warn */ case _: Array[List[String]] => ()
/* nowarn */ case _: Array[Array[String]] => ()
/* warn */ case _: Array[List[Array[String]]] => ()
/* warn */ case _: Array[Array[List[String]]] => ()
}
}
object Matching {
class Q {
type A
type B <: A
def f(xs: Traversable[B]) = xs match {
/* nowarn */ case xs: List[A] => xs.head
/* nowarn */ case xs: Seq[B] => xs.head
/* warn */ case xs: Set[A] => xs.head
}
def f2[T <: B](xs: Traversable[T]) = xs match {
/* nowarn */ case xs: List[B with T] => xs.head
/* nowarn */ case xs: Seq[A] => xs.head
/* nowarn */ case xs: Set[T] => xs.head
}
}
}
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