How to properly use qRegisterMetaType on a class derived from QObject?

Question

I\'ve been searching far and wide for an answer to this but to no avail. My lament is as follows:

I have a ClassA that roughly looks like this:

Answer 1

Here's an update to Chris' solution #2 for Qt 5:

namespace QtMetaTypePrivate {
    template <>
    struct QMetaTypeFunctionHelper {
        static void Delete(void *t)
        {
            delete static_cast(t);
        }

        static void *Create(const void *t)
        {
            Q_UNUSED(t)
            return new ClassA();
        }

        static void Destruct(void *t)
        {
            Q_UNUSED(t) // Silence MSVC that warns for POD types.
            static_cast(t)->~ClassA();
        }

        static void *Construct(void *where, const void *t)
        {
            Q_UNUSED(t)
            return new (where) ClassA;
        }
    #ifndef QT_NO_DATASTREAM
        static void Save(QDataStream &stream, const void *t)
        {
            stream << *static_cast(t);
        }

        static void Load(QDataStream &stream, void *t)
        {
            stream >> *static_cast(t);
        }
    #endif // QT_NO_DATASTREAM
    };
}

If your ClassA doesn't implement operator<< and operator>> helpers for QDataStream, comment out the bodies of Save and Load or you'll still have a compiler error.