let mk ?(ocaml_stdlib = true) ?(camlp4_stdlib = true) () =
          let q = Queue.create ()
          in
            (if ocaml_stdlib
             then include_dir q Camlp4_config.ocaml_standard_library
             else ();
             if camlp4_stdlib
             then
               (include_dir q Camlp4_config.camlp4_standard_library;
                include_dir q
                  (Filename.concat Camlp4_config.camlp4_standard_library
                     "Camlp4Parsers");
                include_dir q
                  (Filename.concat Camlp4_config.camlp4_standard_library
                     "Camlp4Printers");
                include_dir q
                  (Filename.concat Camlp4_config.camlp4_standard_library
                     "Camlp4Filters"))
             else ();
             include_dir q ".";
             q)