title: What is the proper name for a container with these requirements?
body: <p>I need to implement additional container for my library. I need it for holding profile points in my profiler module. Everything is ready to begin coding, however, I am not sure what is the proper name for this kind of container.</p>
  
  <p>What I need, is data structure described as following:</p>
  
  <ul>
  <li>It's a 'multi-level' container (entries can have children).</li>
  <li>There is no root node.</li>
  <li>At the 'top level' it holds list of elements.</li>
  <li>Elements are stored in order they were added.</li>
  <li>Each node can have any number of child nodes.</li>
  </ul>
  
  <p>Example usage:</p>
  
  <pre><code>Container c;
  c.push(5);
  c.push(7);
  c.push_level(); //now, new elements will be added as children of '7'.
  c.push(3);
  c.push(14);
  c.pop_level();
  c.push(6); //this entry will be added to 'root list'.
  </code></pre>
  
  <p>Any ideas?</p>