Setting function pointer inside class - c++

Question

Im trying to create a simple windows api.
I need a little help in setting a function pointer in side class
Im getting errors trying to set the function to a function that is inside a class, Is there anyway this can be done without using static in the class?
class Window
{
public:
WIN_API Window();
struct WIN_API
{
bool(*OnMouseClick)(Vector2D position, MouseButton button);
bool(*OnCreate)();
}Event;
};
class MainWindow : public Window
{
public:
MainWindow() : Window()
{
//error here
this->Event.OnCreate = OnCreate;
this->Event.OnMouseClick = OnMouseClick;
}
bool OnCreate()
{
return true;
}
bool OnMouseClick(Vector2D position, MouseButton button)
{
return true;
}
};

Answer 1

You have to bind the member function of a particular instance. This is best done using a lambda and std::function objects.
class Window
{
public:
Window();
struct WIN_API
{
std::function<bool(Vector2D, MouseButton)> OnMouseClick;
std::function<bool()> OnCreate;
} Event;
};
class MainWindow : public Window
{
public:
MainWindow()
{
this->Event.OnCreate =
[this] () { return this->OnCreate(); };
this->Event.OnMouseClick =
[this] (Vector2D position, MouseButton button)
{ return this->OnMouseClick(position, button); };
}
bool OnCreate()
{
return true;
}
bool OnMouseClick(Vector2D position, MouseButton button)
{
return true;
}
};