The changes literally landed in the past three days; The implementation is theoretically perfect, but once it's (seriously) observed by users it will decay into bugs. That's just basic quantum CS. :-)
I love seeing the difference between Python and C/C++ coder cultures: To a Python'er, bonus points are given for performance and friendly coding is nearly assumed. To a C++'er, bonus points are awarded for friendly coding, and performance is nearly assumed.
(Even more, I love how we're seeing some convergence here: no-compromise improvements to weak spots on each "side" of the programming language spectrum.)