> So, going back to my question, it seems like the small leap from C to C++, if the author embraces the STL, does categorically prevent this class of overflow.

> So, going back to my question, it seems like the small leap from C to C++, if the author embraces the STL, does categorically prevent this class of overflow. "Categorically" is a bit strong; if any index were ever truncated to a 32-bit integer before writing to s[i], that could also cause major issues. Also, the C++ standard library does not have a monopoly on safe interfaces; all of the relevant APIs can be trivially reimplemented in C. It's just that C libraries have not historically made safe internal interfaces a priority.