(primaryPreferred: StringAdd).self
(primaryPreferred: StringFormat).self
(primaryPreferred: ArrowAssoc[PrimaryPreferred]).x
(Since version 2.10.0) Use leftOfArrow
instead
(primaryPreferred: Ensuring[PrimaryPreferred]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
Read from the primary if it is available, or secondaries if it is not.