object typerep { class TypeRep[T] { def getType: TypeRep[T] = this } object BooleanRep extends TypeRep[Boolean] { override def toString = "Boolean" } object CharRep extends TypeRep[Char] { override def toString = "Char" } object IntRep extends TypeRep[Int] { override def toString = "Int" } object LongRep extends TypeRep[Long] { override def toString = "Long" } object FloatRep extends TypeRep[Float] { override def toString = "Float" } object DoubleRep extends TypeRep[Double] { override def toString = "Double" } class ListRep[U, T <: List[U]](val elemRep: TypeRep[U]) extends TypeRep[T] { override def toString = "List[" + elemRep + "]" } implicit def typeRep(x: Boolean): TypeRep[Boolean] = BooleanRep implicit def typeRep(x: Char ): TypeRep[Char ] = CharRep implicit def typeRep(x: Long ): TypeRep[Long ] = LongRep implicit def typeRep(x: Float ): TypeRep[Float ] = FloatRep implicit def typeRep(x: Double ): TypeRep[Double ] = DoubleRep implicit def typeRep(x: Int ): TypeRep[Int ] = IntRep /* implicit def typeRep[T](xs: List[T])(implicit rep: T => TypeRep[T]): TypeRep[List[T]] = new ListRep(rep(xs.head)) */ implicit def typeRep[T <% TypeRep[T]](xs: List[T]): TypeRep[List[T]] = new ListRep(xs.head) } object test extends App { import typerep._ println(3.getType) println(List(3).getType) }