type 'a future

(* future f x executes f x in a separate thread *)
val future : ('a -> 'b) -> 'a -> 'b future

(* block and return the result of the computation when it completes *)
val force : 'a future -> 'a


(* convenient additional functions *)

(* par f x g y executes (f x) and (g y) concurrently *)
val par : ('a -> 'b) -> 'a -> ('c -> 'd) -> 'c -> 'b * 'd

(* f <*> g executes f() and g() concurrently *)
val (<*>) : (unit -> 'a) -> (unit -> 'b) -> 'a * 'b