>>>>> "D" == Daniel Berger <djberg96 / hotmail.com> writes: D> I'm confused - what conversion is it trying to do? I thought these two D> were equivalent: D> if(NIL_P(rbNum)) D> if(Qnil == rbNum) if you want to write the same with rb_scan_args(), you must write if (rb_scan_args(argc, argv, "01", &rbNum)) { rb_thread_wait_for(rb_time_interval(rbNum)); } else { rb_thread_sleep_forever(); } and you see that the ruby version is faster :-) Guy Decoux