let printf : string -> int -> int -> ('a, unit, string, unit) format4 -> 'a =
    let start_time = Sys.time () in
    (fun brick_name brick_verb verb message ->
     Printf.ksprintf
       (fun s ->
        if true
        then Printf.printf "[%s][%.3f]%s" brick_name start_time s else ())
       message);;
              val printf : string -> int -> int -> ('_a, unit, string, unit) format4 -> '_a =
  <fun>
# printf "hi" 5 1 "Bonjour %s !" "tobias";;
[hi][0.061]Bonjour tobias !- : unit = ()
# printf "hi" 5 1 "Bonjour %d !" 5;;
Characters 16-30:
  printf "hi" 5 1 "Bonjour %d !" 5;;
                  ^^^^^^^^^^^^^^
Error: This expression has type
         (string -> unit, string -> unit) CamlinternalFormatBasics.precision
       but an expression was expected of type
         (string -> unit, int -> 'a) CamlinternalFormatBasics.precision
       Type string is not compatible with type int