title: Unicode std::string class replacement
body: <p>I'm looking for suggestions regarding unicode aware std::string library replacements. I have a bunch of code that uses std::string, its iterators etc, and would like to now support unicode strings (free or open source implementations preferred, regex capabilities would be great!). </p>
  
  <p>I'm not sure at this point if I require a complete rewrite or if I can get away with dropping in a new string library that supports all of the std::string interfaces. The unicode world seems very complex and I'm just wanting to enable it in my applications not have to learn every single aspect of it.</p>
  
  <p>btw how does the index operator work when it has to pass back a reference to either a 1, 2,3 or 4 structure which could in theory change to either a 1,2,3 or 4 byte structure.  if a larger or smaller sized value is passed, does the shifting back and forth of the internal data representation occur insitu?</p>