title: Converting from C++ string to unsigned char* and back
body: <p>What would be the code to convert an std::string to unsigned char* and back?</p>
  
  <pre><code>str = "1234567891234567"
  unsigned char* unsignedStr = ConvertStrToUnsignedCharPointer(str);
  str1 = ConvertUnsignedCharToStr(unsignedStr);
  </code></pre>
  
  <p><code>str</code> and <code>str1</code> must be same with no loss of precision.</p>