#include <string>
#include <boost/regex/icu.hpp>
#include <iostream>

const std::string find_exp = "(?s)(?x)(?<=<(?'maintag'italic)>)(?'main'\\((?'innertext'(?>(?|(?:(?:(?![()])(?!<(?!WRK)\\b)(?!</(?!WRK)\\b).)++(?:<(?'tagname'\\w++)[^>]*+>(?'tagbody'(?>(?:(?!<\\k'tagname'\\b)(?!</\\k'tagname'\\b).)++|<\\k'tagname'\\b[^>]*+>(?&tagbody))*+</\\k'tagname'>))?)|(?:<(?'tagname'\\w++)[^>]*+>(?'tagbody'(?>(?:(?!<\\k'tagname'\\b)(?!</\\k'tagname'\\b).)++|<\\k'tagname'\\b[^>]*+>(?&tagbody))*+</\\k'tagname'>))|(?&main)))*+)\\))(?=</\\k'maintag'>)";

const std::string replace_exp = "~~$+{innertext}~~";

const std::string search_in = "<para>The third and final section, <italic>(Part (III))</italic>, consists of the following appendixes</para>";

int test()
{
  boost::u32regex expr = boost::make_u32regex(find_exp);
  boost::u32regex_iterator<std::string::const_iterator> match(search_in.begin(), search_in.end(), expr);
  boost::u32regex_iterator<std::string::const_iterator> end;
  for (; match != end; ++match)
  {
    boost::match_results<std::string::const_iterator> result = *match;
    std::cout << "hit" << std::endl;
    std::string replace_str = result.format(replace_exp, boost::format_perl);
    std::cout << replace_str << std::endl;
  }

  std::cout << "Finished!" << std::endl;

  return 0;
}

int main()
{
  return test();
}