title: Remove all xml tags from a std::string
body: <p>I have a <code>std::string xmlString = "&lt;out&gt;&lt;return&gt;Hello&lt;/return&gt;&lt;/out&gt;"</code> and I want to
  remove all of the tags! (without an additional library, except tinyXML -> already loaded)</p>
  
  <p>result -> Hello</p>
  
  <p>Thx</p>