title: When is it wise to use Singleton classes in Ruby?
body: <p>I was reading about Singletons in Ruby. I never really had the need to use them before, but I got curious and decided to look them up, to see if I should've used them in the past, or maybe  I could use them in the future if I knew <em>what</em> they are used for.</p>
  
  <p>The only times I can think of to use this is:</p>
  
  <ul>
  <li><strong>?</strong> When I need to have a special object. Example: "smart" <code>Hash</code> object, that acts like a normal Ruby hash with a few additional quirks.</li>
  <li>When I want to make it so only one instance of a class can exist.</li>
  </ul>
  
  <p>However, I am not really sure I had the need for either of the above.</p>