title: Can multiple objects be inserted with the << operator in Rails 3.1?
body: <p><strong>Could I write the following ...</strong>   </p>
  
  <pre><code>      raw_data.categories.each do |category|
            obj.categories &lt;&lt; category
        end
  </code></pre>
  
  <p><strong>As the following instead? ...</strong></p>
  
  <pre><code>      obj.categories &lt;&lt; raw_data.categories
  </code></pre>