How to calculate a time difference in C++
<p>What's the best way to calculate a time difference in C++? I'm timing the execution speed of a program, so I'm interested in milliseconds. Better yet, seconds.milliseconds..</p>

<p>The accepted answer works, but needs to include ctime or time.h as noted in the comments. </p>

<blockquote>
  <p>Another answer (dupe) can
  <a href="http://stackoverflow.com/questions/483164/looking-for-benchmarking-code-snippet-c">be found here</a></p>
</blockquote>
