template<typename InputIterator , typename Function > Function for_each (InputIterator begin, InputIterator end, Function f, __gnu_parallel::sequential_tag)
template<typename Iterator , typename Function > Function for_each (Iterator begin, Iterator end, Function f, __gnu_parallel::_Parallelism parallelism_tag)
template<typename Iterator , typename Function > Function for_each (Iterator begin, Iterator end, Function f)