namespace std { template <class Container> class front_insert_iterator { protected: Container* container; public: using iterator_category = output_iterator_tag; using value_type = void; using difference_type = void; using pointer = void; using reference = void; using container_type = Container; explicit front_insert_iterator(Container& x); front_insert_iterator& operator=(const typename Container::value_type& value); front_insert_iterator& operator=(typename Container::value_type&& value); front_insert_iterator& operator*(); front_insert_iterator& operator++(); front_insert_iterator operator++(int); }; template <class Container> front_insert_iterator<Container> front_inserter(Container& x); }