include Core.Invariant.S1 with type 'a t := 'a t
val invariant : 'a Base__.Invariant_intf.inv -> 'a t Base__.Invariant_intf.invval use_is_allowed : _ t -> boolval value_exn : 'a t -> 'aval on_update_exn : 'a t -> f:('a Update.t -> unit) -> unitval disallow_future_use : _ t -> unit