title: How to compare a long long with a double?
body: <p><sup>(This <em>has</em> to be a duplicate, but I can't find a duplicate...)</sup><br>
  How do I properly compare a <code>long long</code> with a <code>double</code> in C++?  </p>
  
  <p>Casting either to the other can cause loss of precision and possibly overflow, so I'm not sure what to do...</p>