Re: address of virtual member function passed as template argument

pascal.zschumme@gmail.com wrote:


You can mimic them to some extent. Here's a rough draft:

class PropertyObserver {
public:
    virtual void PropertyChanged() = 0;
};

template <typename T>
class PropertyHolder {
public:
    PropertyHolder(PropertyObserver* observer) : observer_(observer) {}
    operator T() const { return property_; }
    const PropertyHolder& operator=(const T& p) {
        property_ = p;
        observer_->PropertyChanged();
        return *this;
    }
    // Other operators and constructors left as an exercise for the
reader
private:
    T property_;
    PropertyObserver* observer_;
};

class ClassWithIntProperty : private PropertyObserver {
private:
    void PropertyChanged() {}
public:
    PropertyHolder<int> my_property;

    ClassWithIntProperty() : my_property(this) {}
};

// Usage
ClassWithIntProperty c;
c.my_property = 1; // triggers c.PropertyChanged
int n = c.my_property;

--
With best wishes,
    Igor Tandetnik

With sufficient thrust, pigs fly just fine. However, this is not
necessarily a good idea. It is hard to be sure where they are going to
land, and it could be dangerous sitting under them as they fly
overhead. -- RFC 1925