sig type !'a t val make : 'a -> 'a Atomic.t val get : 'a Atomic.t -> 'a val set : 'a Atomic.t -> 'a -> unit val exchange : 'a Atomic.t -> 'a -> 'a val compare_and_set : 'a Atomic.t -> 'a -> 'a -> bool val fetch_and_add : int Atomic.t -> int -> int val incr : int Atomic.t -> unit val decr : int Atomic.t -> unit end