title: Simple string concatenation
body: <p>If I have a string <code>x='wow'</code> in Python, I can concatenate this string with itself using the <code>__add__</code> function, like so:</p>
  
  <pre><code>x='wow'  
  x.__add__(x)  
  'wowwow'
  </code></pre>
  
  <p>How can I do this in C++?</p>