text: // Copyright (c) 2009-2014 Vladimir Batov.
  // Use, modification and distribution are subject to the Boost Software License,
  // Version 1.0. See http://www.boost.org/LICENSE_1_0.txt.
  
  #ifndef BOOST_CONVERT_SPIRIT_BASED_CONVERTER_HPP
  #define BOOST_CONVERT_SPIRIT_BASED_CONVERTER_HPP
  
  #include <boost/convert/base.hpp>
  #include <boost/convert/detail/forward.hpp>
  #include <boost/spirit/include/qi.hpp>
  #include <boost/spirit/include/karma.hpp>
  
  namespace boost { namespace cnv
  {
      struct spirit;
  }}
  
  struct boost::cnv::spirit : public boost::cnv::cnvbase<boost::cnv::spirit>
  {
      typedef boost::cnv::spirit             this_type;
      typedef boost::cnv::cnvbase<this_type> base_type;
  
      using base_type::operator();
  
      template<typename string_type, typename out_type>
      void
      str_to(cnv::range<string_type> range, optional<out_type>& result_out) const
      {
          typedef typename cnv::range<string_type>::iterator                  iterator;
          typedef typename boost::spirit::traits::create_parser<out_type>::type parser;
  
          iterator    beg = range.begin();
          iterator    end = range.end();
          out_type result;
  
          if (boost::spirit::qi::parse(beg, end, parser(), result))
              if (beg == end) // ensure the whole string has been parsed
                  result_out = result;
      }
      template<typename in_type, typename char_type>
      cnv::range<char_type*>
      to_str(in_type value_in, char_type* beg) const
      {
          typedef typename boost::spirit::traits::create_generator<in_type>::type generator;
  
          char_type* end = beg;
          bool      good = boost::spirit::karma::generate(end, generator(), value_in);
          
          return cnv::range<char_type*>(beg, good ? end : beg);
      }
  };
  
  #endif // BOOST_CONVERT_SPIRIT_BASED_CONVERTER_HPP
  
  