title: How to use the TBB task_arena class with enqueue and wait_until_empty
body: <p>I am looking for an example of how to use the <strong>Threaded Building Blocks</strong> <a href="http://software.intel.com/en-us/node/468318" rel="nofollow">task_arena</a> class with <code>enqueue</code> and <code>wait_until_empty</code>.</p>
  
  <p>Here is the process I am following. As described in the documentation above, add these includes:</p>
  
  <pre><code>#define TBB_PREVIEW_TASK_ARENA 1
  #include "tbb/task.h"
  #include “tbb/task_arena.h”
  </code></pre>
  
  <p>Then, create the tasks with <code>tbb::task::allocate_root</code> and enqueue them using <code>tbb::arena::enqueue</code>.</p>
  
  <p>However, I receive this error on the arena <code>wait_until_empty()</code> method:</p>
  
  <p><strong>error: ‘class tbb::interface7::task_arena’ has no member named ‘wait_until_empty’</strong></p>
  
  <p>I am using the most current release version 4.3, update 3. </p>
  
  <p>Please provide a simple working example.</p>