Both CLIF and pybind11clif aka pybind11k aka pywrapcc seem to be stopped. I thought these were pretty cool projects, I had been following what they did, and even have some of their stuff patched in my local python/c++ ffi code. Did the team just get shifted to something else?
it never gained any real adoption inside google or outside, because it was a lot of work just to get even the most basic bindings. it was really just created because the authors hated swig.