ref: 2f5e8d6a9a76d8a51a5d33146913cde4530a6501 dir: /lib/thread/ncpu+plan9.myr/
use std pkg thread = const ncpu : (-> int) ;; const ncpu = { match std.intparse(std.getenvv("NPROC", "")) | `std.Some n: -> n | `std.None: -> 1 ;; }