Printf

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