Many also need to learn that there are configuration settings on their compilers that make those two cases the same, enabling bounds checking on operator[]().
Sure, but at() is guaranteed to throw an exception and operator[] can throw an exception when you go out of bounds. C++26 is tweaking this, but it's still going to differ implementation to implementation.
At least that's my understanding of the situation. Happy to be corrected though.
At least that's my understanding of the situation. Happy to be corrected though.