classes

$ cat C.scala 
class C[@specialized T](t: T)
class D[@specialized T](t: T) extends C[T](t)

$ scalac C.scala 
C.scala:2: warning: class C must be a trait. Specialized version of class D will inherit generic C[Boolean]
class D[@specialized T](t: T) extends C[T](t)
      ^
one warning found

$ cat D.scala 
object Test extends App {
  val x=new D(3)
  println(x.getClass)
  println(x.getClass.getSuperclass)
  println(x.getClass.getSuperclass.getSuperclass)
}

$ scalac D.scala
$ scala Test
class D$mcI$sp
class D
class C