There is a question of choosing the inner container in the classroom.
The length of the container after initialization will not change. In theory, a class implements an n-dimensional model, but in practice the dimension will not exceed 4.
I understand that there will be no noticeable difference, but from the point of view of the internal structure of these classes - which is faster: references to std::array elements or to std::vector elements?
std::? - PinkTux