Should I return std::string or const char* from a getter?

Question

I'm trying to use std::string instead of char* whenever possible, but I worry I may be degrading performance too much. Is this a good way of returning strings (no error checking for brevity)?

std::string linux_settings_provider::get_home_folder() {
    return std::string(getenv("HOME"));
}

Also, a related question: when accepting strings as parameters, should I receive them as const std::string& or const char*?

Answer 1

Return the string.

I think the better abstraction is worth it. Until you can measure a meaningful performance difference, I'd argue that it's a micro-optimization that only exists in your imagination.

It took many years to get a good string abstraction into C++. I don't believe that Bjarne Stroustroup, so famous for his conservative "only pay for what you use" dictum, would have permitted an obvious performance killer into the language. Higher abstraction is good.