title: aws-s3 gem unless defined? @@{:instance_writer=>true}
body: <p>I am trying to integrate the <a href="https://github.com/marcel/aws-s3">aws-s3</a> gem with the latest version of Rails (4.1.0), and when starting the server I receive this error:</p>
  
  <pre><code>aws-s3-0.6.3/lib/aws/s3/extensions.rb:223:in `class_eval': ///.rvm/gems/ruby-1.9.3-p385/gems/aws-s3-0.6.3/lib/aws/s3/extensions.rb:223: syntax error, unexpected $undefined (SyntaxError) unless defined? @@{:instance_writer=&gt;true}
  </code></pre>
  
  <p>Has anyone got any ideas?</p>
  
  <p>The bulk of the gem has not been updated for over two years so I am thinking that it may finally be out of date.</p>