It would be helpful if clazy could check if a class is able to register itself in Qt's meta-object-system.

Sometimes it is a forgotten include (forward declared) or something like this that the moc cannot see the whole class and won't generate the "qRegisterMetaType" itself. Most times the developer will add qRegisterMetaType somewhere because Qt said it at runtime. But clazy could help here to warn if a class is used in signal/slot and moc is not able to generate the registration as it is the better way to let moc do the registration.

moc can generate q qt_static_metacall with stuff like this:

    } else if (_c == QMetaObject::RegisterMethodArgumentMetaType) {
        switch (_id) {
        default: *reinterpret_cast<int*>(_a[0]) = -1; break;
        case 0:
            switch (*reinterpret_cast<int*>(_a[1])) {
            default: *reinterpret_cast<int*>(_a[0]) = -1; break;
            case 1:
                *reinterpret_cast<int*>(_a[0]) = qRegisterMetaType< QSharedPointer<CUSTOM_CLASS> >(); break;
            }
            break;


moc has some more possibilities to detect own types like Q_PROPERTY usage.

See:
https://code.qt.io/cgit/qt/qtbase.git/tree/src/tools/moc/generator.cpp
https://woboq.com/blog/qmetatype-knows-your-types.html