object typerep extends App { class TypeRep[T] {} case object IntRep extends TypeRep[Int] { override def toString = "Int" } case object BooleanRep extends TypeRep[Boolean] { override def toString = "Boolean" } case class ListRep[T](elemrep: TypeRep[T]) extends TypeRep[List[T]] { override def toString = "List" } implicit def intRep: TypeRep[Int] = IntRep implicit def booleanRep: TypeRep[Boolean] = BooleanRep implicit def listRep[T](implicit elemrep: TypeRep[T]): TypeRep[List[T]] = ListRep(elemrep) def getType[T](x: T)(implicit rep: TypeRep[T]): TypeRep[T] = rep println(getType(1)) println(getType(List(1))) }