title: Convert string to Unicode hex representation and back in C++
body: <p>I want to convert a string into a string which contains all characters of the given string in their Unicode hex notation and back again. Target language is C++.</p>
  
  <p>For example, given the German word <code>Hände</code>, I want to be able to convert this string into it's Unicode hex notation <code>U+0068 U+00E4 U+006E U+0064 U+0065</code>, and from it back to its original representation <code>Hände</code>. </p>
  
  <p>How can this be accomplished in C++? </p>