+Q_DECLARE_METATYPE(Transfer::Status)
+Q_DECLARE_METATYPE(Transfer::Direction)
+
+QDataStream &operator<<(QDataStream &out, Transfer::Status state);
+QDataStream &operator>>(QDataStream &in, Transfer::Status &state);
+QDataStream &operator<<(QDataStream &out, Transfer::Direction direction);
+QDataStream &operator>>(QDataStream &in, Transfer::Direction &direction);
+