RFC1951.KLast
val ctor : 'a -> ('b, 'c, 'd) state
val peek_bits : int -> (([< `Rd | `Wr Rd ] as 'a, 'b) Safe.t -> 'c -> ('b, 'd, 'e) t -> ('b, 'd, 'e) res) -> ('a, 'b) Safe.t -> 'c -> ('b, 'd, 'e) t -> ('b, 'd, 'e) res