C++ has had std::vector::at() - which checks for out-of-bounds indices - since C++98. The reason why it's not used all that much in practice is because indexing is relatively rare - most of the time, you just iterate over collections, or otherwise use iterators rather than raw indices. And there's no ability to opt into bounds checking for C++ iterators in the standard - implementations usually provide some kind of checked iterators for debug builds, but performance is such that you'd never want that enabled for release.