C++ and backwards compatibility
with the exception of 'auto' and some other minor 'nits', C++ code using the old style from the early days SHOULD still compile and run as expected, even with the newest/shiniest C++ standard supported by the compiler.
(At least I haven't run into anything, though a few sloppy constructs "you used to get away with" might cause a bit of grief and require some fixin' with things like explicit casts and proper rvalue/lvalue handling).
Can't say the same thing about Python 2 to 3, now can we??