Function dds_lget_data_available 

pub unsafe extern "C" fn dds_lget_data_available(
    listener: *const dds_listener_t,
    callback: *mut dds_on_data_available_fn,
)

@ingroup listener_getters @component listener_obj @brief Get the data_available callback from the listener structure.

Equivalent to calling @ref dds_lget_data_available_arg with arg and reset_on_invoke set to a null pointer and throwing away the result.

@param[in] listener The pointer to the listener structure, where the callback will be retrieved from @param[out] callback Callback function; may be a null pointer