title: Why don't the push_back in vector<> and list<> containers return the reference to the inserted element?
body: <p>I realize I can get the <strike>iterator</strike> reference by calling <code>back()</code> but why not return it with <code>push_back()</code> as well? Is it for performance reasons? Or is it due to exception safety (similar to why <code>pop_back()</code> doesn't return the popped value)? In either case, please explain.</p>