title: number of passed arguments in a va_list
body: <p>All,</p>
  
  <p>I want to control <code>the number of passed parameters</code> in a va_list.</p>
  
  <pre><code>va_list args;
  va_start(args, fmts);
          vfprintf(stdout, fmts, args);
  va_end(args);
  </code></pre>
  
  <p>Is there any possibility to get the number of parameters  just after a <code>va_start</code>?</p>