correct use of Q_OBJECT_COMPAT_PROPERTY is difficult

void setValue(parameter_type t)
{
    QBindingStorage *storage = qGetBindingStorage(owner());
    auto *bd = storage->bindingData(this);
    // make sure we don't remove the binding if called from the bindingWrapper
    const bool inWrapper = inBindingWrapper(storage);
    if (bd && !inWrapper)
        bd->removeBinding();
    if constexpr (QTypeTraits::has_operator_equal_v<T>)
        if (this->val == t)
            return;
    this->val = t;
    if (!inWrapper)
        notify(bd);
}

QObjectCompatProperty &operator=(parameter_type newValue)
{
    setValue(newValue);
    return *this;
}

#include <QObject>
#include <QDebug>

#include <private/qproperty_p.h>

class Foo : public QObject {
    Q_OBJECT
    Q_PROPERTY(int a READ a WRITE setA BINDABLE bindableA)

public:
    int a() const { return Adata; }
    void setA(int value) {
        if(value == Adata)
            return;
        Adata = value;
        // do some important updates after a changed
    }
    QBindable<int> bindableA() { return &Adata; }

private:
    Q_OBJECT_COMPAT_PROPERTY(Foo, int, Adata, &Foo::setA)
};

int main(){
    QProperty<int> refvalue(5);

    Foo myfoo;
    myfoo.bindableA().setBinding([&](){ return refvalue.value(); });

    // change refvalue, myfoo.a follows
    refvalue = 6;
    assert(myfoo.a() == 6);

    // set myfoo.a to 6, should disconnect property binding (but doesn't)
    myfoo.setA(6);

    refvalue = 8;
    assert(myfoo.a() == 6); // this fails
}

#include "main.moc"