I think there are actually 2 questions: Among professional programmers, at what percentile are you, in terms of C++ knowledge? Of all there is to know about C

I think there are actually 2 questions: Among professional programmers, at what percentile are you, in terms of C++ knowledge? Of all there is to know about C++, how much (in%) do you know? Your answer will depend a great deal on which question you believe this is about.