operator overload

[Renato Araujo <renatox gmail com>]

Hi,

How to make the operator overload in gtk?
Ex:

X is a class Y whit 2 operators overload  (GTK_BUTTON  and GTK_LABEL)
if (GTK_BUTTON(x)) return the gtk_button; 
if (GTK_LABEL(x)) return the gtk_label;