From the perspective of pulling some C++ programmer in 1993 into 2024, and dropping them into a large C++ code base consistently written with the latest C++ idioms.
(And yes, this is humorous exaggeration. But the name of C++ is apt. A C language dedicated to accumulating features.)
It's a pre-increment operator. If it was called ++C you'd have a point :)
I just don't understand how someone could have been working in C++ and not picked up the largest changes even just by osmosis. My code-based "upgraded" to C++11 about a year ago, but I can still read C++17 and am not intimidated by C++20 fragments. YMMV I suppose.
(Giving you the benefit of the doubt you may have taken the comment literally, if so I'd maybe apologize for insulting someone with 41 years of experience in a field that is still young whilst having no knowledge of exactly who you are talking to)