// Invalid because nested hk type parameters are no longer allowed import language._ object Test { def foo = (null: Any) match { case a: A[k] => // error: kinds of the type arguments (k) do not conform to the // expected kinds of the type parameters (type K) in class B. new B[k]() } } class A[K[L[_]]] class B[K[M[_]]] object Test2 { def foo = (null: Any) match { case a: A[k] => new B[k]() // this one worked before as the info of `A` was complete } }