Using a macro to create QObject derived classes

Question

I\'m trying to simplify (i.e. get rid of loads of boilerplate code) the creation of QObject wrapper classes that forward property access of other QObject<

Answer 1

moc doesn't like macros very well. It expands them to some degree, but it fails when they get complicated¹.

You can try to replace signals: with public:² (i.e. manually expanding the signals macro), andtell moc that you want the function to be a signal by putting Q_SIGNAL in front of the function declaration.

Replace

signals:\
    void Notifier( Type value );\

with

public:\
    Q_SIGNAL void Notifier( Type value );\

---

_{¹: for some definition of complicated... I don't know when it fails, but I ran into some different problems in the past. From my experience my guess is that moc has problems when a macro body contains another macro, like signals in your example. But this is just a guess - maybe the kind of macros moc fails at is something else.}

_{²: Before Qt 5, that used to be protected.}