Bidir_tbl.Make
module A : ARG
type t_from = A.From.t
type t_into = A.Into.t
type t
val create : int -> t
val length : t -> int
val add : t -> t_from -> t_into -> unit
val mem_from : t -> t_from -> bool
val get_from : t -> t_from -> t_into option
val mem_into : t -> t_into -> bool
val get_into : t -> t_into -> t_from option
val remove : t -> t_from -> unit