Autoprojection

autoproject.scala

// Finds a R in an T
trait Select[T, R] {
  def apply(t: T): R
}

trait LowPrio {
  implicit def autoLeft[T, R, O]: Select[(R, O), R] = ???
}
object Select extends LowPrio {
  implicit def autoRight[T, R, O]: Select[(O, R), R] = ???
}
def select[T, R](t: T)(implicit sel: Select[T, R]): R = sel(t)

val x = (12, "hello")
val y: Int    = select(x)
val z: String = select(x)