title: How to concatenate a string with chrono::milliseconds?
body: <p>I need to have a string with timestamp in milliseconds in it.
  I got the milliseconds that way (after looking for it here on stackoverflow):</p>
  
  <pre><code>milliseconds ms = duration_cast&lt; milliseconds &gt;(
      system_clock::now().time_since_epoch()
  );
  </code></pre>
  
  <p>now I have to concatenate it like:</p>
  
  <pre><code>string = "something " + ms + " something else";
  </code></pre>
  
  <p>Any help?
  Thank you in advance :)</p>