sig type t external repr : 'a ->Obj.t = "%identity" external obj : Obj.t ->'a = "%identity" external magic : 'a ->'b = "%identity" external is_block : Obj.t -> bool = "obj_is_block" external is_int : Obj.t -> bool = "%obj_is_int" external tag : Obj.t -> int = "obj_tag" external set_tag : Obj.t -> int -> unit = "obj_set_tag" external size : Obj.t -> int = "%obj_size" external truncate : Obj.t -> int -> unit = "obj_truncate" external field : Obj.t -> int ->Obj.t = "%obj_field" external set_field : Obj.t -> int ->Obj.t -> unit = "%obj_set_field" external new_block : int -> int ->Obj.t = "obj_block" external dup : Obj.t ->Obj.t = "obj_dup" val lazy_tag : int val closure_tag : int val object_tag : int val infix_tag : int val forward_tag : int val no_scan_tag : int val abstract_tag : int val string_tag : int val double_tag : int val double_array_tag : int val custom_tag : int val final_tag : int val marshal : Obj.t -> string val unmarshal : string -> int ->Obj.t * int
