title: What does (~0L) mean?
body: <p>I'm doing some X11 ctypes coding, I don't know C but need some help understanding this.</p>
  
  <p>In the C code below (might be C++ im not sure) we see <code>(~0L)</code> what does that mean? In Javascript and Python <code>~0</code> means <code>-1</code>.</p>
  
  <pre><code>812   int result = GetProperty(window, property_name,
  813                            (~0L), // (all of them)
  814                            &amp;type, &amp;format, &amp;num_items, &amp;properties);
  </code></pre>
  
  <p>Thanks</p>