Faster set intersection

There's a few algorithms that are supposed to be faster than O(m+n) time for a set intersection. Most of this are in academic papers that take 10 pages to describe what surely would have been only 1 page in pseudocode, but.. that's academia.

http://fawx.com/2009/10/26/an-ode-to-set-intersection-part-1/
Guy who implemented the Baeza-Yates fast set intersection algorithm including:
https://github.com/erikfrey/themas/blob/master/src/set_intersection/intersect.hpp
his code.