title: C++ default function parameter
body: <p>I want to achieve this:</p>
  
  <pre><code>- second parameter by default set to first argument
  </code></pre>
  
  <p>Something like:</p>
  
  <pre><code>int foo (int a, int b = a);
  </code></pre>
  
  <p>But how to do that?</p>
  
  <p>Thanks a lot!</p>