open Printf
+external nprocs : unit -> int = "nprocs"
+
let failwithf fs = ksprintf failwith fs
let (//) = Filename.concat
let is_directory d = try Sys.is_directory d with Sys_error _ -> false
+let unique = let i = ref 0 in fun () -> incr i; !i
+
(* From OCaml 4.08 sources. We can remove this when we can
* depend on min OCaml 4.08.
*)