I\'ve discovered that std::strings are very slow compared to old-fashioned null-terminated strings, so much slow that they significantly slow down my overall pr
You are most certainly doing something wrong, or at least not comparing "fairly" between STL and your own code. Of course, it's hard to be more specific without code to look at.
It could be that you're structuring your code using STL in a way that causes more constructors to run, or not re-using allocated objects in a way that matches what you do when you implement the operations yourself, and so on.