Exhaustive check during pattern matching on Coproduct

[a-nigredo]

It would be nice to have compilation error if there is a pattern matching on not all injected values.
e.g.

type Primitive = Cop[String :: Boolean :: TNil
object Primitive {
  val Str= Cop.Inject[String, Primitive]
  val Bool= Cop.Inject[Boolean, Primitive]
}
def print(v: Primitive) =
  v match {
    case Str(v) => println(v)
  }

should throw compilation error since there is not Bool case