> C++ has a lot of features which are not best practices. For example, you're not supposed to use the builtin arrays anymore, in favor of vector<>.

Again, you know better than this. I don't know why you are making these claims, and it's very disappointing to see you make whole sequences of them.

There are no "built-in" arrays in C++. There's C-style arrays, which are there for compatibility with C, and then there's C++'s STL. Since C++'s inception, the recommendation is to use C++'s containers. In STL, there is std::array and std::vector. Which one you pick, it's up to your use case.

This isn't a gotcha. This is C++ 101.