Lazy - should not compile, stackoverflow

gistfile1.scala

trait TC[T] {
  def apply(t: T): String
}

object TC {
  implicit def hnilTC: TC[HNil] =
    new TC[HNil] {
      def apply(l: HNil) = "HNil"
    }

  implicit def hconsTC[H, T <: HList](implicit
    headTC: Lazy[TC[H]],
    tailTC: Lazy[TC[T]]
  ): TC[H :: T] =
    new TC[H :: T] {
      def apply(l: H :: T) = s"${headTC.value(l.head)} :: ${tailTC.value(l.tail)}"
    }

  implicit def projectTC[F, G](implicit
    gen: Generic.Aux[F, G],
    tc: Lazy[TC[G]]
  ): TC[F] =
    new TC[F] {
      def apply(f: F) = tc.value(gen.to(f))
    }
}

case class Bar(i: Int, s: String)

object Dummy extends App {
  
  val barTC = implicitly[TC[Bar]]
  
  Console.out.println(barTC(Bar(2, "a")))  
  
}