`sig
val fprintf :
Pervasives.out_channel ->
('r, Pervasives.out_channel, unit) Pervasives.format -> 'r
val printf : ('r, Pervasives.out_channel, unit) Pervasives.format -> 'r
val eprintf : ('r, Pervasives.out_channel, unit) Pervasives.format -> 'r
val ifprintf : 'a -> ('r, 'a, unit) Pervasives.format -> 'r
val sprintf : ('r, unit, string) Pervasives.format -> 'r
val bprintf : Buffer.t -> ('r, Buffer.t, unit) Pervasives.format -> 'r
val kfprintf :
(Pervasives.out_channel -> 'a) ->
Pervasives.out_channel ->
('r, Pervasives.out_channel, unit, 'a) Pervasives.format4 -> 'r
val ksprintf :
(string -> 'a) -> ('r, unit, string, 'a) Pervasives.format4 -> 'r
val kbprintf :
(Buffer.t -> 'a) ->
Buffer.t -> ('r, Buffer.t, unit, 'a) Pervasives.format4 -> 'r
val failwithf : ('r, unit, string, unit -> 'a) Pervasives.format4 -> 'r
val invalid_argf : ('r, unit, string, unit -> 'a) Pervasives.format4 -> 'r
val exitf : ('r, unit, string, unit -> 'a) Pervasives.format4 -> 'r
end`