(roundRobiner: StringAdd).self
(roundRobiner: StringFormat).self
(roundRobiner: ArrowAssoc[RoundRobiner[A, M]]).x
(Since version 2.10.0) Use leftOfArrow instead
(roundRobiner: Ensuring[RoundRobiner[A, M]]).x
(Since version 2.10.0) Use resultOfEnsuring instead
(Since version 0.11.10) Will be made private