passing method pointer as a function pointer

Hi!

i have this code:

Code:

---

class MainWindow
{
        void                load();
[...]
        void                ee_resize_cb (Ecore_Evas * _ee);
};

void
MainWindow::load()
{
        [...]
        ecore_evas_callback_resize_set(ee, ee_resize_cb);
}

---

The protorype for ecore_evas_callback_resize_set() is:

Code:

---

void ecore_evas_callback_resize_set ( Ecore_Evas * ee, void(*)(Ecore_Evas *ee) func)

---

The compiler gives error:

Code:

---

main-window.cpp:79: error: argument of type
‘void (MainWindow::)(Ecore_Evas*)’ does not match ‘void (*)(Ecore_Evas*)’

---

If I try to pass &ee_resize_cb to the function, i get another error:

Code:

---

main-window.cpp:79: error: ISO C++ forbids taking the address
of an unqualified or parenthesized non-static member function to form a pointer to member function. 
Say ‘&MainWindow::ee_resize_cb’

---

How can I pass a method pointer as a function pointer, then?
Thanks for your help!

This will get you up-to-speed with function pointers in C/C++: http://www.newty.de/fpt/index.html

gg

For the second error, you must do &MainWindow::ee_resize_cb, as the compile error says. Just doing ee_resize_cb or &ee_resize_cb on a class function is illegal.
But class function pointers and non-class function pointers use different syntax so be sure to read the link.

Ok, I think I understand the problem now. If I declare ee_resize_cb() as an instance method, it takes an extra hidden argument, the this pointer.

But what could be the solution? If I declare ee_resize_cb() as a static method, I have no access to the members of MainWindow.

Read the link. It is possible to use class function pointers - they just use a different syntax and require the address of the instance of the class whose function you want to call.

Thanks for the help! I declared ee_resize_cb() as a static method and I made a static pointer which points to this. That tutorial is really elaborated!

Unfortunately, using multiple instances could make this solution much more complex. But luckily i need only one MainWindow ^^