val get_uint16 : bytes -> int -> int
val get_int16 : bytes -> int -> int
val get_int32 : bytes -> int -> int32
val get_int64 : bytes -> int -> int64
val set_int16 : bytes -> int -> int -> unit
val set_int32 : bytes -> int -> int32 -> unit
val set_int64 : bytes -> int -> int64 -> unit