title: Creation of unique type ID with c++11
body: <p>Why is the following code guaranteed to be a unique typeID ?!</p>
  
  <pre><code>using TypeId = uintptr_t; 
  
  template &lt; typename T &gt;
  static TypeId GetTypeId()
  {
     static uint32_t placeHolder;
     return (reinterpret_cast&lt;TypeId&gt;(&amp;placeHolder));
  } 
  </code></pre>
  
  <p><a href="http://www.codeproject.com/Articles/723656/SW-Message-Bus" rel="noreferrer">Source</a></p>
  
  <p>I don't understand why this is not just a kind of random memory location as a kind of "misused"... Thanks for answers in advance.</p>