title: Using Regex in new MongoDB library for PHP7/HHVM
body: <p>Trying to figure out how to use Regex in new <a href="http://fi2.php.net/manual/en/set.mongodb.php" rel="nofollow">MongoDB library</a> </p>
  
  <p>I didn't find real world example of usage MongoDB\BSON\Regex so I come up with the code below:</p>
  
  <pre><code>$manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");
  
  $bulk = new MongoDB\Driver\BulkWrite;
  $bulk-&gt;insert(['word' =&gt; ['word' =&gt; 'heelo']]);
  $bulk-&gt;insert(['word' =&gt; ['word' =&gt; 'hello']]);
  $manager-&gt;executeBulkWrite('db.collection', $bulk);
  
  $filter = ['word' =&gt; ['word' =&gt; new MongoDB\BSON\Regex("hello","i")]];
  
  $query = new MongoDB\Driver\Query($filter);
  $cursor = $manager-&gt;executeQuery('db.collection', $query);
  
  foreach ($cursor as $document) {
      var_dump($document);
  }
  </code></pre>
  
  <p>But it shows nothing. Does anyone know how to use it?</p>