How efficient is std::string compared to null-terminated strings?

Question

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

Answer 1

Good performance isn't always easy with STL, but generally, it is designed to give you the power. I found Scott Meyers' "Effective STL" an eye-opener for understanding how to deal with the STL efficiently. Read!

As others said, you are probably running into frequent deep copies of the string, and compare that to a pointer assignment / reference counting implementation.

Generally, any class designed towards your specific needs, will beat a generic class that's designed for the general case. But learn to use the generic class well, and learn to ride the 80:20 rules, and you will be much more efficient than someone rolling everything on their own.

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One specific drawback of std::string is that it doesn't give performance guarantees, which makes sense. As Tim Cooper mentioned, STL does not say whether a string assignment creates a deep copy. That's good for a generic class, because reference counting can become a real killer in highly concurrent applications, even though it's usually the best way for a single threaded app.