title: C++ vector of vectors declaration
body: <p>I am not really sure what this line of code does.</p>
  
  <pre><code> vector&lt;vector&lt;A&gt;&gt; someth;
  </code></pre>
  
  <p>Does this mean that creates a vector with elements vectors with objects of class A? 
  Can please someone explain this?</p>
  
  <p>Thanks </p>