sig
type elem = hashable
type t = elem Hash_set.t
type sexpable = t
val sexp_of_t : sexpable -> Sexplib.Sexp.t
val t_of_sexp : Sexplib.Sexp.t -> sexpable
val create : ?growth_allowed:bool -> ?size:int -> unit -> t
val of_list : elem list -> t
end