defprotocol XMAVLink.Message do @spec pack(XMAVLink.Message.t(), 1 | 2) :: { :ok, XMAVLink.Types.message_id(), { :ok, XMAVLink.Types.crc_extra(), pos_integer, :broadcast | :system | :system_component | :component }, binary() } | {:error, String.t()} def pack(message, version) end defimpl XMAVLink.Message, for: [Atom, BitString, Float, Function, Integer, List, Map, PID, Port, Reference, Tuple] do def pack(not_a_message, _), do: {:error, "pack(): #{inspect(not_a_message)} is not a MAVLink message"} end