add CCThread.spawn{1,2}

src/threads/CCThread.ml

@@ -6,6 +6,10 @@ type t = Thread.t
 
 let spawn f = Thread.create f ()
 
+let spawn1 f x = Thread.create f x
+
+let spawn2 f x y = Thread.create (fun () -> f x y) ()
+
 let detach f = ignore (Thread.create f ())
 
 module Arr = struct

src/threads/CCThread.mli

@@ -7,9 +7,17 @@
 
 type t = Thread.t
 
-val spawn : (unit -> 'a) -> t
+val spawn : (unit -> _) -> t
 (** [spawn f] creates a new thread that runs [f ()] *)
 
+val spawn1 : ('a -> _) -> 'a -> t
+(** [spawn1 f x] is like [spawn (fun () -> f x)].
+    @since NEXT_RELEASE *)
+
+val spawn2 : ('a -> 'b -> _) -> 'a -> 'b -> t
+(** [spawn2 f x y] is like [spawn (fun () -> f x y)].
+    @since NEXT_RELEASE *)
+
 val detach : (unit -> 'a) -> unit
 (** [detach f] is the same as [ignore (spawn f)] *)