Scala Pattern: factory method

Factory_method.scala

trait Animal
private class Dog extends Animal
private class Cat extends Animal

trait Wanna
case object WannaCat extends Wanna
case object WannaDog extends Wanna

trait AnimalFactory[Wanna] {
  def create(): Animal
}

object Animal {
  def apply[T <: Wanna](kind: T)(implicit factory: AnimalFactory[T]) =
   factory.create()
}

implicit val canMakeCat = new AnimalFactory[WannaCat.type] {
  def create(): Animal = new Cat()
}

implicit val canMakeDog = new AnimalFactory[WannaDog.type] {
  def create(): Animal = new Dog()
}