# #show_module Set;;
module Set :
  sig
    module type OrderedType = sig type t val compare : t -> t -> int end
    module type S =
      sig
        type elt
        type t
        val empty : t
        val is_empty : t -> bool
        val mem : elt -> t -> bool
        val add : elt -> t -> t
        val singleton : elt -> t
        val remove : elt -> t -> t
        val union : t -> t -> t
        val inter : t -> t -> t
        val diff : t -> t -> t
        val compare : t -> t -> int
        val equal : t -> t -> bool
        val subset : t -> t -> bool
        val iter : (elt -> unit) -> t -> unit
        val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a
        val for_all : (elt -> bool) -> t -> bool
        val exists : (elt -> bool) -> t -> bool
        val filter : (elt -> bool) -> t -> t
        val partition : (elt -> bool) -> t -> t * t
        val cardinal : t -> int
        val elements : t -> elt list
        val min_elt : t -> elt
        val max_elt : t -> elt
        val choose : t -> elt
        val split : elt -> t -> t * bool * t
        val find : elt -> t -> elt
        val of_list : elt list -> t
      end
    module Make : functor (Ord : OrderedType) -> sig  end
  end
# module StrSet = Set.Make(String);;
module StrSet :
  sig
    type elt = String.t
    type t = Set.Make(String).t
    val empty : t
    val is_empty : t -> bool
    val mem : elt -> t -> bool
    val add : elt -> t -> t
    val singleton : elt -> t
    val remove : elt -> t -> t
    val union : t -> t -> t
    val inter : t -> t -> t
    val diff : t -> t -> t
    val compare : t -> t -> int
    val equal : t -> t -> bool
    val subset : t -> t -> bool
    val iter : (elt -> unit) -> t -> unit
    val fold : (elt -> 'a -> 'a) -> t -> 'a -> 'a
    val for_all : (elt -> bool) -> t -> bool
    val exists : (elt -> bool) -> t -> bool
    val filter : (elt -> bool) -> t -> t
    val partition : (elt -> bool) -> t -> t * t
    val cardinal : t -> int
    val elements : t -> elt list
    val min_elt : t -> elt
    val max_elt : t -> elt
    val choose : t -> elt
    val split : elt -> t -> t * bool * t
    val find : elt -> t -> elt
    val of_list : elt list -> t
  end
# #show_module String;;
module String :
  sig
    external length : string -> int = "%string_length"
    external get : string -> int -> char = "%string_safe_get"
    external set : bytes -> int -> char -> unit = "%string_safe_set"
    external create : int -> bytes = "caml_create_string"
    val make : int -> char -> string
    val copy : string -> string
    val sub : string -> int -> int -> string
    val fill : bytes -> int -> int -> char -> unit
    val blit : string -> int -> bytes -> int -> int -> unit
    val concat : string -> string list -> string
    val iter : (char -> unit) -> string -> unit
    val iteri : (int -> char -> unit) -> string -> unit
    val map : (char -> char) -> string -> string
    val trim : string -> string
    val escaped : string -> string
    val index : string -> char -> int
    val rindex : string -> char -> int
    val index_from : string -> int -> char -> int
    val rindex_from : string -> int -> char -> int
    val contains : string -> char -> bool
    val contains_from : string -> int -> char -> bool
    val rcontains_from : string -> int -> char -> bool
    val uppercase : string -> string
    val lowercase : string -> string
    val capitalize : string -> string
    val uncapitalize : string -> string
    type t = string
    val compare : t -> t -> int
    external unsafe_get : string -> int -> char = "%string_unsafe_get"
    external unsafe_set : bytes -> int -> char -> unit = "%string_unsafe_set"
    external unsafe_blit : string -> int -> bytes -> int -> int -> unit
      = "caml_blit_string" "noalloc"
    external unsafe_fill : bytes -> int -> int -> char -> unit
      = "caml_fill_string" "noalloc"
  end
# let s = StrSet.of_list ["dsf"; "fds"];;
val s : StrSet.t = <abstr>
# StrSet.elements s;;
- : StrSet.elt list = ["dsf"; "fds"]