Create pyside widget in C/C++

I have a very complex custom widget derived from QWidget in PySide.

At first its paintEvent was taking more than 1sec to complete. Then I've implemented a lot of caching with QPixmap to each layer of the "image" that I'm drawing. Now my paintEvent finishes in about 90ms, that is really fine, but not enough.

I'm wondering if I can implement this custom widget in plain C or C++ and them use it as an abstract widget in PySide (like PySide does with all other available widget).

I found here that in PyQt I could use sip for this. But I can't find a match for this in PySide.

Does any one knows who to do that?