title: Golang mgo result into simple slice
body: <p>I'm fairly new to both Go and MongoDB. Trying to select a single field from the DB and save it in an int slice without any avail.</p>
  
  <pre><code>userIDs := []int64{}
  
  coll.Find(bson.M{"isdeleted": false}).Select(bson.M{"userid": 1}).All(&amp;userIDs)
  </code></pre>
  
  <p>The above prints out an empty slice. However, if I create a struct with a single <code>ID</code> field that is int64 with marshalling then it works fine.</p>
  
  <p>All I am trying to do is work with a simple slice containing IDs that I need instead of a struct with a single field. All help is appreciated.</p>