MergeableEither

Allows use of a merge method to extract values from Either instances regardless of whether they are Left or Right.

val l = Left(List(1)): Either[List[Int], Vector[Int]]
val r = Right(Vector(1)): Either[List[Int], Vector[Int]]
l.merge: Seq[Int] // List(1)
r.merge: Seq[Int] // Vector(1)