It has not been mentioned in the original post or the comments yet, so here is a working prototype of a similar idea https://github.com/pfultz2/Pythy (for some specific value of working, you will need Clang)

Its birth lies here Having it all: Pythy syntax for C++ [1]. It was a nice read. Unfortunately cpp-next seems to be down right now. Let me try to find it in Google's cache or internet archive.

Here it is https://web.archive.org/web/20130820172127/http://cpp-next.c...

[1] http://cpp-next.com/archive/2011/11/having-it-all-pythy-synt...