class QtQObjectTemplateWorkaround: public QObject
{
    Q_OBJECT
signals:
    void valueChanged();
};

template<typename T>
class BoilerplateHolder: public QtQObjectTemplateWorkaround {
public:
   BoilerplateHolder(T&& value): m_value{std::forward<T>(value)} {}
   BoilerplateHolder(const BoilerplateHolder<T>& bh){ m_value = bh.m_value; }
   void operator =(const BoilerplateHolder<T>& bh) { m_value = bh.m_value;}
   void operator =(T&& value) { m_value = std::forward<T>(value); valueChanged(); }
   operator T() const { return m_value; }
private:
   T m_value;
};

class Something: public QObject
{
    Q_OBJECT
    Q_PROPERTY(BoilerplateHolder<int> minPowerLevel MEMBER m_minPowerLevel)
    Q_PROPERTY(BoilerplateHolder<int> maxPowerLevel MEMBER m_maxPowerLevel)
private:
    BoilerplateHolder<int> m_minPowerLevel{0};
    BoilerplateHolder<int> m_maxPowerLevel{0};
};