Contains the definition of the class template sub_match<> and associated helper functions

namespace boost {
  namespace xpressive {
    template<typename BidiIter> struct sub_match;
    template<typename BidiIter, typename Char, typename Traits> 
      std::basic_ostream< Char, Traits > & 
      operator<<(std::basic_ostream< Char, Traits > &, 
                 sub_match< BidiIter > const &);
    template<typename BidiIter> 
      bool operator==(sub_match< BidiIter > const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator!=(sub_match< BidiIter > const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator<(sub_match< BidiIter > const & lhs, 
                     sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator<=(sub_match< BidiIter > const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator>=(sub_match< BidiIter > const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator>(sub_match< BidiIter > const & lhs, 
                     sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator==(typename iterator_value< BidiIter >::type const * lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator!=(typename iterator_value< BidiIter >::type const * lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator<(typename iterator_value< BidiIter >::type const * lhs, 
                     sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator>(typename iterator_value< BidiIter >::type const * lhs, 
                     sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator>=(typename iterator_value< BidiIter >::type const * lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator<=(typename iterator_value< BidiIter >::type const * lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator==(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const * rhs);
    template<typename BidiIter> 
      bool operator!=(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const * rhs);
    template<typename BidiIter> 
      bool operator<(sub_match< BidiIter > const & lhs, 
                     typename iterator_value< BidiIter >::type const * rhs);
    template<typename BidiIter> 
      bool operator>(sub_match< BidiIter > const & lhs, 
                     typename iterator_value< BidiIter >::type const * rhs);
    template<typename BidiIter> 
      bool operator>=(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const * rhs);
    template<typename BidiIter> 
      bool operator<=(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const * rhs);
    template<typename BidiIter> 
      bool operator==(typename iterator_value< BidiIter >::type const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator!=(typename iterator_value< BidiIter >::type const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator<(typename iterator_value< BidiIter >::type const & lhs, 
                     sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator>(typename iterator_value< BidiIter >::type const & lhs, 
                     sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator>=(typename iterator_value< BidiIter >::type const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator<=(typename iterator_value< BidiIter >::type const & lhs, 
                      sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      bool operator==(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const & rhs);
    template<typename BidiIter> 
      bool operator!=(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const & rhs);
    template<typename BidiIter> 
      bool operator<(sub_match< BidiIter > const & lhs, 
                     typename iterator_value< BidiIter >::type const & rhs);
    template<typename BidiIter> 
      bool operator>(sub_match< BidiIter > const & lhs, 
                     typename iterator_value< BidiIter >::type const & rhs);
    template<typename BidiIter> 
      bool operator>=(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const & rhs);
    template<typename BidiIter> 
      bool operator<=(sub_match< BidiIter > const & lhs, 
                      typename iterator_value< BidiIter >::type const & rhs);
    template<typename BidiIter> 
      sub_match< BidiIter >::string_type 
      operator+(sub_match< BidiIter > const & lhs, 
                sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      sub_match< BidiIter >::string_type 
      operator+(sub_match< BidiIter > const & lhs, 
                typename iterator_value< BidiIter >::type const & rhs);
    template<typename BidiIter> 
      sub_match< BidiIter >::string_type 
      operator+(typename iterator_value< BidiIter >::type const & lhs, 
                sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      sub_match< BidiIter >::string_type 
      operator+(sub_match< BidiIter > const & lhs, 
                typename iterator_value< BidiIter >::type const * rhs);
    template<typename BidiIter> 
      sub_match< BidiIter >::string_type 
      operator+(typename iterator_value< BidiIter >::type const * lhs, 
                sub_match< BidiIter > const & rhs);
    template<typename BidiIter> 
      sub_match< BidiIter >::string_type 
      operator+(sub_match< BidiIter > const & lhs, 
                typename sub_match< BidiIter >::string_type const & rhs);
    template<typename BidiIter> 
      sub_match< BidiIter >::string_type 
      operator+(typename sub_match< BidiIter >::string_type const & lhs, 
                sub_match< BidiIter > const & rhs);
  }
}