module Flags:sig..end
type t 
Epoll.Flags.t is an immutable set of flags for which one can register
        interest for a file descriptor.  It is implemented as a bitmask, and so all
        operations (+, -, etc.) are constant time with no allocation.
        sexp_of_t produces a human-readable list of bits, e.g. "(in out)".
include Flags.S
val none : t
val in_ : t
val out : t
val pri : t
val err : t
val hup : t
val et : t
val oneshot : t
val sexp_of_t : t -> Sexplib.Sexp.t