namespace boost {
  namespace algorithm {
    template<typename InputIter, typename Sentinel, typename T> 
      BOOST_CXX14_CONSTEXPR InputIter 
      find_not(InputIter first, Sentinel last, const T & x);
    template<typename Range, typename T> 
      BOOST_CXX14_CONSTEXPR boost::range_iterator< Range >::type 
      find_not(Range & r, const T & x);
  }
}