package monocle.function import monocle.Lens import scala.annotation.implicitNotFound @implicitNotFound("Could not find an instance of Field4[${S},${A}], please check Monocle instance location policy to " + "find out which import is necessary") trait Field4[S, A] extends Serializable { /** Creates a Lens from S to it is fourth element */ def fourth: Lens[S, A] } object Field4 extends Field4Functions trait Field4Functions { def fourth[S, A](implicit ev: Field4[S, A]): Lens[S, A] = ev.fourth }