Conversion from QProperty to QBinding

[Asperamanca]

I have adopted the following pattern when writing my QML-facing C++ property classes:

class CProp : public QObject
{
    Q_OBJECT
    QML_ELEMENT
    QML_UNCREATABLE("Controlled by C++")

    Q_PROPERTY(qreal x BINDABLE getBindableX READ default FINAL)
private:
    QProperty<qreal> m_X;

public:
     QBindable<qreal> getBindableX() { return &m_X;}
};

It's easy to write, it's convenient, and it seems to work.
Two things trouble me:

• The conversion from QProperty to QBindable via '&' does not seem to be documented. I must have taken it from some blog post or example, but I'm worried that I use an unsupported implicit conversion that might go away in the future
• Could the getter be const? Does a QBindable allow changing the property within?

[Asperamanca]

So I suspect things work because QUntypedBindable (base class of QBindable) has a constructor accepting a template parameter pointer ("Property"), so my guess is that "&m_X" provides a pointer to QProperty<qreal>, which is accepted as template parameter in the constructor of QUntypedBindable. Then the whole thing is cast to QBindable, but is that safe?