trying to convert HList to List[LUB]

Test.scala

import shapeless.{::, HList, HNil}
import shapeless.LUBConstraint._
import shapeless.ops.hlist.ToTraversable._

import scala.util.Try
import shapeless.ops.hlist._

object Path {
  def /(s: String) = Path(PathLiteral(s) :: HNil)

  def param[T](name: String) = PathParameter(name)
}


sealed trait PathSegment[+T]
case class PathLiteral(value: String) extends PathSegment[String]
case class PathParameter[+T](name: String) extends PathSegment[T]


case class Path[L <: HList : <<:[PathSegment[_]]#λ](segments: L)
                                                   (implicit ev: ToList[L, PathSegment[_]])
{
  def /(literal: String) = Path(PathLiteral(literal) :: segments)

  def /[T](param: PathParameter[T]) = Path(param :: segments)

  override def toString: String = s"Path(${segments.toList.reverse})"
}

object Test extends App {

  import Path.param
  val myPath = Path / "v1" / "pets" / param[String]("name") / "pictures"
  println(myPath)

}