title: Add empty spacer Widget cause memory leak in Qt?
body: <p>In many Qt tutorials, I see people doing this to add in a spacer in toolbar or status bar:</p>
  
  <pre><code>tb = my_toolbar;
  QWidget* empty = new QWidget();
  empty-&gt;setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Preferred);
  tb-&gt;addWidget(empty);
  tb-&gt;addWidget(otherWidget);
  </code></pre>
  
  <p>And they never do:</p>
  
  <pre><code>delete empty
  </code></pre>
  
  <p>at anywhere. Isn't this a memory leak? Why many people is still doing this way?</p>