Function fdf_dispatcher_downcast_async_dispatcher 

pub unsafe extern "C" fn fdf_dispatcher_downcast_async_dispatcher(
    async_dispatcher: *mut async_dispatcher_t,
) -> *mut fdf_dispatcher_t

Returns an unowned dispatcher provided an async dispatcher. If |async_dispatcher| was not retrieved via |fdf_dispatcher_get_async_dispatcher|, the call will result in a crash.