23 Iterators library [iterators]

23.5 Iterator adaptors [predef.iterators]

23.5.2 Insert iterators [insert.iterators]

23.5.2.3 Class template front_­insert_­iterator [front.insert.iterator]

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

23.5.2.3.1 Operations [front.insert.iter.ops]

constexpr explicit front_insert_iterator(Container& x);
Effects: Initializes container with addressof(x).
constexpr front_insert_iterator& operator=(const typename Container::value_type& value);
Effects: As if by: container->push_­front(value);
Returns: *this.
constexpr front_insert_iterator& operator=(typename Container::value_type&& value);
Effects: As if by: container->push_­front(std​::​move(value));
Returns: *this.
constexpr front_insert_iterator& operator*();
Returns: *this.
constexpr front_insert_iterator& operator++(); constexpr front_insert_iterator operator++(int);
Returns: *this.

23.5.2.3.2 front_­inserter [front.inserter]

template<class Container> constexpr front_insert_iterator<Container> front_inserter(Container& x);
Returns: front_­insert_­iterator<Container>(x).