(************************************************************
   return_thread_value.ml	Created      : Tue Oct  7 13:19:08 2003
  			Last modified: Tue Oct 07 13:28:58 2003
  Compile: ocamlc -thread unix.cma threads.cma return_thread_value.ml -o return_thread_value #
  FTP Directory: sources/ocaml #
************************************************************)
(**

  @author Takashi Masuyama <mamewo@dk9.so-net.ne.jp>

*)

let future f x = 
  (* 結果の書き込み先をローカルにする。 *)
  let result = ref [] in
  let t = Thread.create (fun x -> result := (f x)::!result) x in
  (t, result)
;;

(* ううむ、なにか違う名前だったような.... *)
let attach (t, result) =
  begin
    Thread.join t;
    match !result with
      hd::[] -> hd
    | _ -> failwith "???"
  end
;;

let _ =
  let id = future (fun x -> "Mr. "^x) "mamewo" in
  print_endline "hoge";
  print_endline (attach id)