Function rcl_sys::rcl::wait::rcl_wait_set_add_guard_condition

pub unsafe extern "C" fn rcl_wait_set_add_guard_condition(
    wait_set: *mut rcl_wait_set_t, 
    guard_condition: *const rcl_guard_condition_t, 
    index: *mut usize
) -> rcl_ret_t

Store a pointer to the guard condition in the next empty spot in the set.