/* USB::Configuration#interfaces */
static VALUE
rusb_config_interfaces(VALUE v)
{
  struct usb_config_descriptor *p = get_usb_config_descriptor(v);
  int i;
  VALUE interface = rb_ary_new2(p->bNumInterfaces);
  for (i = 0; i < p->bNumInterfaces; i++)
    rb_ary_store(interface, i, rusb_interface_make(&p->interface[i], v));
  return interface;
}