trouble documenting private enums exported publically to QML

See https://codereview.qt-project.org/#patch,all,70927,3 for details. In this case qquickdialogassets_p.h contains the QQuickStandardButton class which exists only for the purpose of exposing a private enum StandardButton to QML, via

qmlRegisterUncreatableType<QQuickStandardButton>(uri, 1, 1, "StandardButton",
            QLatin1String("Do not create objects of type StandardButton"));

There is no .cpp file because the class has no methods. So I put this in qquickplatformmessagedialog.cpp alongside all the other documentation

    \enum QQuickStandardButton::StandardButton

and get this error

qquickplatformmessagedialog.cpp:325: warning: Cannot find 'QQuickStandardButton::StandardButton' specified with '\enum' in any header file

Perhaps because of that, the table explaining how the enums are used looks weird too: MessageDialog::StandardButton.Ok instead of just StandardButton.Ok, and no known value for it because it didn't "see" the enum itself.