hlist-func.scala

import shapeless._

object PrintPoly extends Poly1 {
  implicit def default[T] = at[(String,T)](_ match {
    case (s, Some(x))        => () => println(s"option: $s = $x")
    case (s, None)           => () => println(s"option: $s = None")
    case (s, x)              => () => println(s"normal: $s = $x")
  })
}

object StringPoly extends Poly1 {
  implicit def default[T] = at[(String,T)](_ match {
    case (s, Some(x))        => s"option: $s = $x"
    case (s, None)           => s"option: $s = None"
    case (s, x)              => s"normal: $s = $x"
  })
}

val list = ("title", "the job title") :: ("id", 99) :: ("isactive", true) :: ("property", Some("value"))  :: ("property2", None) :: HNil

list.map(PrintPoly).toList.foreach { _ () }

list.map(StringPoly).toList.foreach { println }