title: Calling closure assigned to object property directly
body: <p>I would like to be able to call a closure that I assign to an object's property directly without reassigning the closure to a variable and then calling it. Is this possible?</p>
  
  <p>The code below doesn't work and causes <code>Fatal error: Call to undefined method stdClass::callback()</code>.</p>
  
  <pre><code>$obj = new stdClass();
  $obj-&gt;callback = function() {
      print "HelloWorld!";
  };
  $obj-&gt;callback();
  </code></pre>