namespace boost {
  namespace text {
    template<nf Normalization, typename Char, typename String> 
      struct basic_text;
    template<nf Normalization, typename Char, typename String> 
      text_sort_key 
      collation_sort_key(basic_text< Normalization, Char, String > const &, 
                         collation_table const &, 
                         collation_flags = collation_flags::none);
    template<nf Normalization1, typename Char1, typename String1, 
             nf Normalization2, typename Char2, typename String2> 
      int collate(basic_text< Normalization1, Char1, String1 > const &, 
                  basic_text< Normalization2, Char2, String2 > const &, 
                  collation_table const &, 
                  collation_flags = collation_flags::none);
    template<nf Normalization, typename Char, typename String, typename T> 
      basic_text< Normalization, Char, String > 
      operator+(basic_text< Normalization, Char, String >, T const &);
    template<nf Normalization, typename Char, typename String, typename T> 
      basic_text< Normalization, Char, String > 
      operator+(T const &, basic_text< Normalization, Char, String >);
    namespace literals {
      text operator""_t(char const *, std::size_t);
    }
  }
}