type_class_and_superclass.scala

sealed trait Fruits

object Fruits {
  case class Banana() extends  Fruits
  case class Apple() extends  Fruits
}

// This could be just FruitsBehaviou[-A]
trait FruitsBehavior[-A <: Fruits] {
  def price(a: A): Int
}

object FruitsBehavior {
  import Fruits._

  def price[A <: Fruits : FruitsBehavior](a: A): Int =
    implicitly[FruitsBehavior[A]].price(a)

  implicit object BananaInstance extends FruitsBehavior[Banana] {
    override def price(a: Banana): Int = 0
  }

  implicit object AppleInstance extends FruitsBehavior[Apple] {
    override def price(a: Apple): Int = 1
  }
}

object ThePlaceWhereIUse {

  import Fruits._

  def main(args: Array[String]): Unit =
    println(FruitsBehavior.price(Apple()))
}