ref: f2e8e641bf8ee06fa5128c522b151a7f4d9d003b
dir: /lib/thread/util.myr/
use std
use thread
pkg thrtestutil =
	const mkherd : (n : uint32, fn : (-> void) ->void)
;;
const mkherd = {n, fn
	for var i = 0; i < n; i++
		std.try(thread.spawn(fn))
	;;
}