Hacker News Reader

STL uses 'value semantics'. Just use push_back in a loop and observe how often the whole data in std::vector is copied. Not to mention std::sort.

vector::emplace_back ameliorates by allowing new elements to be constructed in-place [1]

Value semantics are the only sensible default in a language like C++. If you need reference semantics, store (smart) pointers explicitly.