val return : 'a -> 'a Deferred.tval bind : 'a Deferred.t -> f:('a -> 'a Deferred.t) -> 'a Deferred.tval map : 'a Deferred.t -> f:('a -> 'b) -> 'a Deferred.tval both : 'a Deferred.t -> 'a Deferred.t -> 'a Deferred.tmodule Open_on_rhs : sig ... end