namespace boost {
  namespace text {
    template<code_point_iter I, std::sentinel_for< I > S = I> 
      struct stream_safe_iterator;
    template<typename I, std::sentinel_for< I > S = I> struct stream_safe_view;
    typedef in_out_result< I, O > copy_result;
    template<typename I, typename S> 
      constexpr auto 
      operator==(stream_safe_iterator< I, S > const & lhs, S rhs);
    template<typename I, typename S> 
      auto operator==(S lhs, stream_safe_iterator< I, S > const & rhs);
    template<typename I, typename S> 
      constexpr auto 
      operator!=(stream_safe_iterator< I, S > const & lhs, S rhs);
    template<typename I, typename S> 
      auto operator!=(S lhs, stream_safe_iterator< I, S > const & rhs);
    namespace v1 {
      template<code_point_iter I, std::sentinel_for< I > S, 
               std::weakly_incrementable O> 
        constexpr copy_result< I, O > stream_safe_copy(I, S, O);
      template<code_point_range R, std::weakly_incrementable O> 
        constexpr copy_result< std::ranges::borrowed_iterator_t< R >, O > 
        stream_safe_copy(R &&, O);
      template<code_point_iter I, std::sentinel_for< I > S> 
        constexpr code_point_iter auto stream_safe(I, S);
      template<code_point_range R> unspecified stream_safe(R &&);
      template<code_point_iter I, std::sentinel_for< I > S> 
        constexpr bool is_stream_safe(I, S);
      template<code_point_range R> constexpr bool is_stream_safe(R &&);
      template<code_point_iter I, std::sentinel_for< I > S> 
        unspecified as_stream_safe(I, S);
      template<code_point_range R> unspecified as_stream_safe(R &&);
      template<typename CPIter, typename Sentinel, typename OutIter> 
        constexpr auto 
        stream_safe_copy(CPIter first, Sentinel last, OutIter out);
      template<typename CPRange, typename OutIter> 
        constexpr auto stream_safe_copy(CPRange && r, OutIter out);
      template<typename CPIter, typename Sentinel> 
        constexpr auto stream_safe(CPIter first, Sentinel last);
      template<typename CPRange> constexpr auto stream_safe(CPRange && r);
      template<typename CPIter, typename Sentinel> 
        constexpr auto is_stream_safe(CPIter first, Sentinel last);
      template<typename CPRange> constexpr auto is_stream_safe(CPRange && r);
    }
  }
}namespace std {
  namespace ranges {
  }
}