Int64_u.OptionThis allows us to represent t option without allocating for Some _ tags. Some (min_value ()) is not representable because its representation would overlap with the representation of None.
type value = tval to_option : t -> Boxed.t Base.optionval of_option : Boxed.t Base.option -> tval to_local_option : t -> Boxed.t Base.option @ localval of_local_option : Boxed.t Base.option @ local -> tmodule Optional_syntax : sig ... end