title: std::function and std::bind: what are they, and when should they be used?
body: <p>I know what functors are and when to use them with <code>std</code> algorithms, but I haven't understood what Stroustrup says about them in the <a href="http://www.stroustrup.com/C++11FAQ.html#std-function" rel="noreferrer">C++11 FAQ</a>.</p>
  
  <p>Can anyone explain what <code>std::bind</code> and <code>std::function</code> are, when they should be used, and give some examples for newbies?</p>