ex20 - https://medium.com/@lu4nm3/bend-any-type-to-your-will-with-ad-hoc-polymorphism-4e6d326f1ff0

ex20_bend.scala

trait GlutenFree[T] {
  def isGlutenFree(item: T): Boolean
}

object GlutenFree {
  implicit val baguetteGlutenFree: GlutenFree[Baguette] = new GlutenFree[Baguette] {
    def isGlutenFree(b: Baguette): Boolean = true
  }

  implicit val croissantGlutenFree: GlutenFree[Croissant] = new GlutenFree[Croissant] {
    def isGlutenFree(c: Croissant): Boolean = true
  }
}