title: std::string& vs boost::string_ref
body: <p>Does it matter anymore if I use <code>boost::string_ref</code> over <code>std::string&amp;</code> ? I mean, is it really more efficient to use <code>boost::string_ref</code> over the std version when you are processing strings ? I don't really get the explanation offered here: <a href="http://www.boost.org/doc/libs/1_61_0/libs/utility/doc/html/string_ref.html" rel="noreferrer">http://www.boost.org/doc/libs/1_61_0/libs/utility/doc/html/string_ref.html</a> . What really confuses me is the fact that <code>std::string</code> is also a handle class that only points to the allocated memory, and since c++11, with move semantics the copy operations noted in the article above are not going to happen. So, which one is more efficient ?</p>