std::vector and std::string were designed in the '90s, and came with C++98. They have been modernized, somewhat, with move constructors and the like, but in answer to your implied question, no, they are not modern designs, and they still have sharp edges. That is a burden of backward compatibility.

But you knew they came from C++98. Maybe you meant to ask if I still use them? I do. But I don't store references to their elements.