+- Some classes (notably wxBitmap and wxImage) don't define operator==() as it
+ used to work in somewhat unexpected way as it compared only internal pointers
+ and not the object data. The code using it will have to be updated:
+ * If the object was compared with wxNullXXX, use IsOk() method instead
+ * If valid object need to be compated, use IsSameAs() to reproduce the old
+ behaviour or change the code to avoid comparing bitmaps &c