title: stringify arbitrary number of variables
body: <p>For a single variable (or a given number of variables), it's easy to use macros to stringify variables. E.g. for 2 variables, I can do:</p>
  
  <pre><code>#define STRINGIFY(var1, var2) (std::string(#var1) + " " + #var2)
  </code></pre>
  
  <p>Is there a way to extend the above with either variadic macros or some other sort of compile-time trickery, to ultimately get a <code>STRINGIFY</code> function that accepts an arbitrary number of arguments?</p>