title: Polish chars in std::string
body: <p>I have a problem. I'm writing an app in Polish (with, of course, polish chars) for Linux and I receive 80 warnings when compiling. These are just "warning: multi-character character constant" and "warning: case label value exceeds maximum value for type". I'm using std::string.</p>
  
  <p>How do I replace std::string class?</p>
  
  <p>Please help.
  Thanks in advance.
  Regards.</p>