(doubleOps: StringAdd).+(other)
(doubleOps: StringAdd).self
(doubleOps: StringFormat).self
(doubleOps: ArrowAssoc[DoubleOps]).x
(Since version 2.10.0) Use leftOfArrow
instead
(doubleOps: Ensuring[DoubleOps]).x
(Since version 2.10.0) Use resultOfEnsuring
instead