title: Rails scope with boolean
body: <p>When you're using a boolean in Rails with Active Record, and you ask (say) <code>visible?</code>, it checks the column for whether it is <code>true</code> or not. If it is <code>false</code> or <code>nil</code>, <code>visible?</code> will return <code>false</code>.</p>
  
  <p>How do you scope a boolean to ask if the <code>?</code> method would return false? I have this:</p>
  
  <pre><code>scope :visible, where(hide: [nil, false])
  </code></pre>
  
  <p>but am wondering if there is a cleaner way. Is there a way to write this scope without explicitly saying both <code>nil</code> and <code>false</code>? If we were after the opposite, we could just write</p>
  
  <pre><code>scope :invisible, where(hide: true)
  </code></pre>
  
  <p>which seems cleaner. What's the best code for the <strong>visible</strong> scope?</p>