https://stackoverflow.com/q/45137119/3314107

Person.scala

  object Person {
    def unapply(arg: Person): Option[(String, Int, Boolean)] =
      Some(arg.name, arg.age, arg.valid)
  }

  trait Person {
    def name: String
    def age: Int
    def valid: Boolean
  }

  case class MarriedPerson(
    name: String,
    age: Int,
    valid: Boolean,
    spouse: Person) extends Person

  val bob = MarriedPerson("bob", 27, false, null)
  val alice = MarriedPerson("alice", 27, true, bob)

  println(alice match {
    case MarriedPerson("charlotte", _, _, Person("bob", _, _)) => "charlotte is married to bob"
    case MarriedPerson("alice", _, _, Person("desmond", _, _)) => "alice is married to desmond"
    case MarriedPerson("alice", _, _, Person("bob", _, _)) => "alice is married to bob"
    case _ => "no one is married"
  })