Printf

`sig
val fprintf :
Stdlib.out_channel -> ('a, Stdlib.out_channel, unit) Stdlib.format -> 'a
val printf : ('a, Stdlib.out_channel, unit) Stdlib.format -> 'a
val eprintf : ('a, Stdlib.out_channel, unit) Stdlib.format -> 'a
val sprintf : ('a, unit, string) Stdlib.format -> 'a
val bprintf :
Stdlib.Buffer.t -> ('a, Stdlib.Buffer.t, unit) Stdlib.format -> 'a
val ifprintf : 'b -> ('a, 'b, 'c, unit) Stdlib.format4 -> 'a
val kfprintf :
(Stdlib.out_channel -> 'd) ->
Stdlib.out_channel ->
('a, Stdlib.out_channel, unit, 'd) Stdlib.format4 -> 'a
val ikfprintf : ('b -> 'd) -> 'b -> ('a, 'b, 'c, 'd) Stdlib.format4 -> 'a
val ksprintf :
(string -> 'd) -> ('a, unit, string, 'd) Stdlib.format4 -> 'a
val kbprintf :
(Stdlib.Buffer.t -> 'd) ->
Stdlib.Buffer.t -> ('a, Stdlib.Buffer.t, unit, 'd) Stdlib.format4 -> 'a
val kprintf : (string -> 'b) -> ('a, unit, string, 'b) Stdlib.format4 -> 'a
end`