I having typing issues with sprintf:

# Printf.sprintf "%a";;
- : (unit -> '_a -> string) -> '_a -> string = <fun>

whereas:

# Printf.printf "%a";;
- : (out_channel -> '_a -> unit) -> '_a -> unit = <fun>

Am I missing something out here? If not why can't sprintf accept the
same printers as the other?

Cheers,
Till

PS: This affects Ocaml 3.9.03 and 3.10 beta, Format and Printf...