object MyHList {

    trait HL[A] {
      type Head <: A
      type Tail <: HL[_]
    }
    /*class HNil extends HL[Nothing] {
      type Tail = Nothing
    }*/
    type HNil = HL[Nothing] { type Tail = Nothing }
    type ::[A,B <: HL[_]] = HL[A] {
      type Head=A
      type Tail = B
    }
    //type hl2func[A <: HL[_],O] = hl2func[A#Tail,A#Head] => O

    trait HL2Func[HList <: HL[_], O] {
      type hl2func = HL2Func[HList#Tail,HList#Head]#hl2func => O
    }

    type x = Int :: String :: HNil
    //type x = ::[Int, ::[String, HNil]]
  }