title: MongoDB opposite of $addToSet
body: <p>I'm aware of the <a href="http://docs.mongodb.org/manual/reference/operator/addToSet/" rel="noreferrer">$addToSet</a> method for MongoDB, but I can't find a &quot;remove&quot; equivalent anywhere in the docs.</p>
  <p>What's the best way to achieve this? Trying to achieve something like the following:</p>
  <pre><code>obj = {
    name: 'object1',
    tags: ['fus', 'ro', 'dah']
  }
  
  db.collection.update({
    name: 'object1'
  }, {
    $removeFromSet: {
      tags: 'dah'
    }
  });
  </code></pre>