namespace boost {
  namespace text {
    typedef subrange< Iter, Sentinel > foreach_subrange_range;
    typedef subrange< Iter > search_result;
    template<typename Iter, typename Sentinel> 
      std::ptrdiff_t distance(Iter, Sentinel);
    template<typename BidiIter, typename Sentinel, typename T> 
      BidiIter find(BidiIter, Sentinel, T const &);
    template<typename BidiIter, typename Sentinel, typename T> 
      BidiIter find_not(BidiIter, Sentinel, T const &);
    template<typename BidiIter, typename Sentinel, typename Pred> 
      BidiIter find_if(BidiIter, Sentinel, Pred);
    template<typename BidiIter, typename Sentinel, typename Pred> 
      BidiIter find_if_not(BidiIter, Sentinel, Pred);
    template<typename BidiIter, typename T> 
      BidiIter find_backward(BidiIter, BidiIter, T const &);
    template<typename BidiIter, typename T> 
      BidiIter find_not_backward(BidiIter, BidiIter, T const &);
    template<typename BidiIter, typename Pred> 
      BidiIter find_if_backward(BidiIter, BidiIter, Pred);
    template<typename BidiIter, typename Pred> 
      BidiIter find_if_not_backward(BidiIter, BidiIter, Pred);
    template<typename FwdIter, typename Sentinel, typename Func> 
      Func foreach_subrange(FwdIter, Sentinel, Func);
    template<typename FwdIter, typename Sentinel, typename Func, 
             typename Proj> 
      Func foreach_subrange(FwdIter, Sentinel, Func, Proj);
    template<typename FwdIter, typename Sentinel, typename T, typename Func> 
      Func foreach_subrange_of(FwdIter, Sentinel, T const &, Func);
    template<typename FwdIter, typename Sentinel, typename Pred, 
             typename Func> 
      Func foreach_subrange_if(FwdIter, Sentinel, Pred, Func);
    template<typename Iter, typename Sentinel, typename Pred> 
      bool all_of(Iter, Sentinel, Pred);
    template<typename Iter1, typename Sentinel1, typename Iter2, 
             typename Sentinel2> 
      bool equal(Iter1, Sentinel1, Iter2, Sentinel2);
    template<typename Iter1, typename Sentinel1, typename Iter2, 
             typename Sentinel2> 
      std::pair< Iter1, Iter2 > mismatch(Iter1, Sentinel1, Iter2, Sentinel2);
    template<typename Iter1, typename Sentinel1, typename Iter2, 
             typename Sentinel2> 
      int lexicographical_compare_three_way(Iter1, Sentinel1, Iter2, 
                                            Sentinel2);
    template<typename Iter1, typename Sentinel1, typename Iter2, 
             typename Sentinel2> 
      search_result< Iter1 > search(Iter1, Sentinel1, Iter2, Sentinel2);
    template<typename Iter1, typename Sentinel1, typename Iter2, 
             typename Sentinel2, typename Pred> 
      Iter1 find_first_of(Iter1, Sentinel1, Iter2, Sentinel2, Pred);
  }
}namespace std {
  namespace ranges {
  }
}