title: What is the difference between std::reference_wrapper and a simple pointer?
body: <p>Why is there a need to have <a href="http://en.cppreference.com/w/cpp/utility/functional/reference_wrapper" rel="noreferrer"><code>std::reference_wrapper</code></a>? Where should it be used? How is it different from a simple pointer? How its performance compares to a simple pointer?</p>