CvSize does not exist?

I have installed the official python bindings for OpenCv and I am implementing some standard textbook functions just to get used to the python syntax. I have run into the problem, however, that CvSize does not actually exist, even though it is documented on the site...

The simple function: blah = cv.CvSize(inp.width/2, inp.height/2) yields the error 'module' object has no attribute 'CvSize'. I have imported with 'import cv'.

Is there an equivalent structure? Do I need something more? Thanks.