Handmade Shapeless. Naive, but functional and still succinct.

NaiveShapeless.scala

trait SList[T] {
  def ::[H](head: H): ::[H, T] = new ::(head, this)
}
type SNil = Nothing
case object SNil extends SList[SNil]
case class ::[H, T](head: H, tail: SList[T]) extends SList[H :: T] {
  override def toString = s"$head :: $tail"
}

println(
  "A" :: 1 :: SNil
)
List(
  "A" :: 1 :: SNil,
  "B" :: 2 :: 3 :: SNil,
  "C" :: "D" :: SNil
).foreach(slist => slist match {
  case (s: String) :: (i: Int) :: _ =>
    println(s"string: $s, than int: $i")
  case a :: (b: String) :: _ =>
    println(s"something: $a than string: $b")
})

case class Example(ds: Double :: String :: SNil)
val e = Example(2.72 :: "e" :: SNil)
println(e)

In the future I may implement a CSV converter using the CSV converter example from the original Shapeless:
https://github.com/milessabin/shapeless/blob/main/examples/src/main/scala/shapeless/examples/csv.scala
(This example shows how to createa a serializer/deserializer from CSV to products.)