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1545 lines
64 KiB
Plaintext
1545 lines
64 KiB
Plaintext
[#unordered_node_map]
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== Class Template unordered_node_map
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:idprefix: unordered_node_map_
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`boost::unordered_node_map` — A node-based, open-addressing unordered associative container that associates unique keys with another value.
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`boost::unordered_node_map` uses an open-addressing layout like `boost::unordered_flat_map`, but,
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being node-based, it provides pointer/iterator stability and node handling functionalities.
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Its performance lies between those of `boost::unordered_map` and `boost::unordered_flat_map`.
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As a result of its using open addressing, the interface of `boost::unordered_node_map` deviates in
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a number of aspects from that of `boost::unordered_map`/`std::unordered_map`:
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- `begin()` is not constant-time.
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- `erase(iterator)` returns `void`.
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- There is no API for bucket handling (except `bucket_count`).
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- The maximum load factor of the container is managed internally and can't be set by the user.
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Other than this, `boost::unordered_node_map` is mostly a drop-in replacement of standard
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unordered associative containers.
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=== Synopsis
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[listing,subs="+macros,+quotes"]
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-----
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// #include <boost/unordered/unordered_node_map.hpp>
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namespace boost {
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template<class Key,
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class T,
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class Hash = boost::hash<Key>,
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class Pred = std::equal_to<Key>,
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class Allocator = std::allocator<std::pair<const Key, T>>>
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class unordered_node_map {
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public:
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// types
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using key_type = Key;
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using mapped_type = T;
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using value_type = std::pair<const Key, T>;
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using init_type = std::pair<
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typename std::remove_const<Key>::type,
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typename std::remove_const<T>::type
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>;
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using hasher = Hash;
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using key_equal = Pred;
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using allocator_type = Allocator;
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using pointer = typename std::allocator_traits<Allocator>::pointer;
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using const_pointer = typename std::allocator_traits<Allocator>::const_pointer;
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using reference = value_type&;
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using const_reference = const value_type&;
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using size_type = std::size_t;
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using difference_type = std::ptrdiff_t;
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using iterator = _implementation-defined_;
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using const_iterator = _implementation-defined_;
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using node_type = _implementation-defined_;
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using insert_return_type = _implementation-defined_;
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// construct/copy/destroy
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xref:#unordered_node_map_default_constructor[unordered_node_map]();
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explicit xref:#unordered_node_map_bucket_count_constructor[unordered_node_map](size_type n,
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const hasher& hf = hasher(),
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const key_equal& eql = key_equal(),
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const allocator_type& a = allocator_type());
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template<class InputIterator>
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xref:#unordered_node_map_iterator_range_constructor[unordered_node_map](InputIterator f, InputIterator l,
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size_type n = _implementation-defined_,
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const hasher& hf = hasher(),
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const key_equal& eql = key_equal(),
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const allocator_type& a = allocator_type());
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xref:#unordered_node_map_copy_constructor[unordered_node_map](const unordered_node_map& other);
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xref:#unordered_node_map_move_constructor[unordered_node_map](unordered_node_map&& other);
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template<class InputIterator>
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xref:#unordered_node_map_iterator_range_constructor_with_allocator[unordered_node_map](InputIterator f, InputIterator l, const allocator_type& a);
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explicit xref:#unordered_node_map_allocator_constructor[unordered_node_map](const Allocator& a);
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xref:#unordered_node_map_copy_constructor_with_allocator[unordered_node_map](const unordered_node_map& other, const Allocator& a);
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xref:#unordered_node_map_move_constructor_with_allocator[unordered_node_map](unordered_node_map&& other, const Allocator& a);
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xref:#unordered_node_map_initializer_list_constructor[unordered_node_map](std::initializer_list<value_type> il,
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size_type n = _implementation-defined_
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const hasher& hf = hasher(),
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const key_equal& eql = key_equal(),
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const allocator_type& a = allocator_type());
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xref:#unordered_node_map_bucket_count_constructor_with_allocator[unordered_node_map](size_type n, const allocator_type& a);
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xref:#unordered_node_map_bucket_count_constructor_with_hasher_and_allocator[unordered_node_map](size_type n, const hasher& hf, const allocator_type& a);
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template<class InputIterator>
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xref:#unordered_node_map_iterator_range_constructor_with_bucket_count_and_allocator[unordered_node_map](InputIterator f, InputIterator l, size_type n, const allocator_type& a);
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template<class InputIterator>
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xref:#unordered_node_map_iterator_range_constructor_with_bucket_count_and_hasher[unordered_node_map](InputIterator f, InputIterator l, size_type n, const hasher& hf,
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const allocator_type& a);
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xref:#unordered_node_map_initializer_list_constructor_with_allocator[unordered_node_map](std::initializer_list<value_type> il, const allocator_type& a);
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xref:#unordered_node_map_initializer_list_constructor_with_bucket_count_and_allocator[unordered_node_map](std::initializer_list<value_type> il, size_type n,
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const allocator_type& a);
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xref:#unordered_node_map_initializer_list_constructor_with_bucket_count_and_hasher_and_allocator[unordered_node_map](std::initializer_list<value_type> il, size_type n, const hasher& hf,
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const allocator_type& a);
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xref:#unordered_node_map_destructor[~unordered_node_map]();
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unordered_node_map& xref:#unordered_node_map_copy_assignment[operator++=++](const unordered_node_map& other);
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unordered_node_map& xref:#unordered_node_map_move_assignment[operator++=++](unordered_node_map&& other)
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noexcept(boost::allocator_traits<Allocator>::is_always_equal::value ||
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boost::allocator_traits<Allocator>::propagate_on_container_move_assignment::value);
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unordered_node_map& xref:#unordered_node_map_initializer_list_assignment[operator++=++](std::initializer_list<value_type>);
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allocator_type xref:#unordered_node_map_get_allocator[get_allocator]() const noexcept;
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// iterators
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iterator xref:#unordered_node_map_begin[begin]() noexcept;
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const_iterator xref:#unordered_node_map_begin[begin]() const noexcept;
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iterator xref:#unordered_node_map_end[end]() noexcept;
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const_iterator xref:#unordered_node_map_end[end]() const noexcept;
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const_iterator xref:#unordered_node_map_cbegin[cbegin]() const noexcept;
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const_iterator xref:#unordered_node_map_cend[cend]() const noexcept;
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// capacity
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++[[nodiscard]]++ bool xref:#unordered_node_map_empty[empty]() const noexcept;
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size_type xref:#unordered_node_map_size[size]() const noexcept;
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size_type xref:#unordered_node_map_max_size[max_size]() const noexcept;
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// modifiers
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template<class... Args> std::pair<iterator, bool> xref:#unordered_node_map_emplace[emplace](Args&&... args);
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template<class... Args> iterator xref:#unordered_node_map_emplace_hint[emplace_hint](const_iterator position, Args&&... args);
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std::pair<iterator, bool> xref:#unordered_node_map_copy_insert[insert](const value_type& obj);
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std::pair<iterator, bool> xref:#unordered_node_map_copy_insert[insert](const init_type& obj);
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std::pair<iterator, bool> xref:#unordered_node_map_move_insert[insert](value_type&& obj);
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std::pair<iterator, bool> xref:#unordered_node_map_move_insert[insert](init_type&& obj);
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iterator xref:#unordered_node_map_copy_insert_with_hint[insert](const_iterator hint, const value_type& obj);
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iterator xref:#unordered_node_map_copy_insert_with_hint[insert](const_iterator hint, const init_type& obj);
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iterator xref:#unordered_node_map_move_insert_with_hint[insert](const_iterator hint, value_type&& obj);
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iterator xref:#unordered_node_map_copy_insert_with_hint[insert](const_iterator hint, init_type&& obj);
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template<class InputIterator> void xref:#unordered_node_map_insert_iterator_range[insert](InputIterator first, InputIterator last);
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void xref:#unordered_node_map_insert_initializer_list[insert](std::initializer_list<value_type>);
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insert_return_type xref:#unordered_node_map_insert_node[insert](node_type&& nh);
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iterator xref:#unordered_node_map_insert_node_with_hint[insert](const_iterator hint, node_type&& nh);
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template<class... Args>
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std::pair<iterator, bool> xref:#unordered_node_map_try_emplace[try_emplace](const key_type& k, Args&&... args);
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template<class... Args>
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std::pair<iterator, bool> xref:#unordered_node_map_try_emplace[try_emplace](key_type&& k, Args&&... args);
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template<class K, class... Args>
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std::pair<iterator, bool> xref:#unordered_node_map_try_emplace[try_emplace](K&& k, Args&&... args);
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template<class... Args>
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iterator xref:#unordered_node_map_try_emplace_with_hint[try_emplace](const_iterator hint, const key_type& k, Args&&... args);
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template<class... Args>
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iterator xref:#unordered_node_map_try_emplace_with_hint[try_emplace](const_iterator hint, key_type&& k, Args&&... args);
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template<class K, class... Args>
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iterator xref:#unordered_node_map_try_emplace_with_hint[try_emplace](const_iterator hint, K&& k, Args&&... args);
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template<class M>
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std::pair<iterator, bool> xref:#unordered_node_map_insert_or_assign[insert_or_assign](const key_type& k, M&& obj);
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template<class M>
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std::pair<iterator, bool> xref:#unordered_node_map_insert_or_assign[insert_or_assign](key_type&& k, M&& obj);
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template<class K, class M>
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std::pair<iterator, bool> xref:#unordered_node_map_insert_or_assign[insert_or_assign](K&& k, M&& obj);
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template<class M>
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iterator xref:#unordered_node_map_insert_or_assign_with_hint[insert_or_assign](const_iterator hint, const key_type& k, M&& obj);
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template<class M>
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iterator xref:#unordered_node_map_insert_or_assign_with_hint[insert_or_assign](const_iterator hint, key_type&& k, M&& obj);
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template<class K, class M>
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iterator xref:#unordered_node_map_insert_or_assign_with_hint[insert_or_assign](const_iterator hint, K&& k, M&& obj);
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void xref:#unordered_node_map_erase_by_position[erase](iterator position);
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void xref:#unordered_node_map_erase_by_position[erase](const_iterator position);
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size_type xref:#unordered_node_map_erase_by_key[erase](const key_type& k);
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template<class K> size_type xref:#unordered_node_map_erase_by_key[erase](K&& k);
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iterator xref:#unordered_node_map_erase_range[erase](const_iterator first, const_iterator last);
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void xref:#unordered_node_map_swap[swap](unordered_node_map& other)
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noexcept(boost::allocator_traits<Allocator>::is_always_equal::value ||
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boost::allocator_traits<Allocator>::propagate_on_container_swap::value);
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node_type xref:#unordered_node_map_extract_by_position[extract](const_iterator position);
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node_type xref:#unordered_node_map_extract_by_key[extract](const key_type& key);
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template<class K> node_type xref:#unordered_node_map_extract_by_key[extract](K&& key);
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void xref:#unordered_node_map_clear[clear]() noexcept;
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template<class H2, class P2>
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void xref:#unordered_node_map_merge[merge](unordered_node_map<Key, T, H2, P2, Allocator>& source);
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template<class H2, class P2>
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void xref:#unordered_node_map_merge[merge](unordered_node_map<Key, T, H2, P2, Allocator>&& source);
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// observers
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hasher xref:#unordered_node_map_hash_function[hash_function]() const;
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key_equal xref:#unordered_node_map_key_eq[key_eq]() const;
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// map operations
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iterator xref:#unordered_node_map_find[find](const key_type& k);
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const_iterator xref:#unordered_node_map_find[find](const key_type& k) const;
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template<class K>
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iterator xref:#unordered_node_map_find[find](const K& k);
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template<class K>
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const_iterator xref:#unordered_node_map_find[find](const K& k) const;
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size_type xref:#unordered_node_map_count[count](const key_type& k) const;
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template<class K>
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size_type xref:#unordered_node_map_count[count](const K& k) const;
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bool xref:#unordered_node_map_contains[contains](const key_type& k) const;
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template<class K>
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bool xref:#unordered_node_map_contains[contains](const K& k) const;
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std::pair<iterator, iterator> xref:#unordered_node_map_equal_range[equal_range](const key_type& k);
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std::pair<const_iterator, const_iterator> xref:#unordered_node_map_equal_range[equal_range](const key_type& k) const;
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template<class K>
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std::pair<iterator, iterator> xref:#unordered_node_map_equal_range[equal_range](const K& k);
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template<class K>
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std::pair<const_iterator, const_iterator> xref:#unordered_node_map_equal_range[equal_range](const K& k) const;
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// element access
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mapped_type& xref:#unordered_node_map_operator[operator[+]+](const key_type& k);
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mapped_type& xref:#unordered_node_map_operator[operator[+]+](key_type&& k);
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template<class K> mapped_type& xref:#unordered_node_map_operator[operator[+]+](K&& k);
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mapped_type& xref:#unordered_node_map_at[at](const key_type& k);
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const mapped_type& xref:#unordered_node_map_at[at](const key_type& k) const;
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template<class K> mapped_type& xref:#unordered_node_map_at[at](const K& k);
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template<class K> const mapped_type& xref:#unordered_node_map_at[at](const K& k) const;
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// bucket interface
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size_type xref:#unordered_node_map_bucket_count[bucket_count]() const noexcept;
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// hash policy
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float xref:#unordered_node_map_load_factor[load_factor]() const noexcept;
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float xref:#unordered_node_map_max_load_factor[max_load_factor]() const noexcept;
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void xref:#unordered_node_map_set_max_load_factor[max_load_factor](float z);
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size_type xref:#unordered_node_map_max_load[max_load]() const noexcept;
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void xref:#unordered_node_map_rehash[rehash](size_type n);
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void xref:#unordered_node_map_reserve[reserve](size_type n);
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};
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// Deduction Guides
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template<class InputIterator,
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class Hash = boost::hash<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>>,
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class Pred = std::equal_to<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>>,
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class Allocator = std::allocator<xref:#unordered_node_map_iter_to_alloc_type[__iter-to-alloc-type__]<InputIterator>>>
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unordered_node_map(InputIterator, InputIterator, typename xref:#unordered_node_map_deduction_guides[__see below__]::size_type = xref:#unordered_node_map_deduction_guides[__see below__],
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Hash = Hash(), Pred = Pred(), Allocator = Allocator())
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-> unordered_node_map<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>, xref:#unordered_node_map_iter_mapped_type[__iter-mapped-type__]<InputIterator>, Hash,
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Pred, Allocator>;
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template<class Key, class T, class Hash = boost::hash<Key>,
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class Pred = std::equal_to<Key>,
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class Allocator = std::allocator<std::pair<const Key, T>>>
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unordered_node_map(std::initializer_list<std::pair<Key, T>>,
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typename xref:#unordered_node_map_deduction_guides[__see below__]::size_type = xref:#unordered_node_map_deduction_guides[__see below__], Hash = Hash(),
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Pred = Pred(), Allocator = Allocator())
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-> unordered_node_map<Key, T, Hash, Pred, Allocator>;
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template<class InputIterator, class Allocator>
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unordered_node_map(InputIterator, InputIterator, typename xref:#unordered_node_map_deduction_guides[__see below__]::size_type, Allocator)
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-> unordered_node_map<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>, xref:#unordered_node_map_iter_mapped_type[__iter-mapped-type__]<InputIterator>,
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boost::hash<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>>,
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std::equal_to<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>>, Allocator>;
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template<class InputIterator, class Allocator>
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unordered_node_map(InputIterator, InputIterator, Allocator)
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-> unordered_node_map<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>, xref:#unordered_node_map_iter_mapped_type[__iter-mapped-type__]<InputIterator>,
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boost::hash<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>>,
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std::equal_to<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>>, Allocator>;
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template<class InputIterator, class Hash, class Allocator>
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unordered_node_map(InputIterator, InputIterator, typename xref:#unordered_node_map_deduction_guides[__see below__]::size_type, Hash,
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Allocator)
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-> unordered_node_map<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>, xref:#unordered_node_map_iter_mapped_type[__iter-mapped-type__]<InputIterator>, Hash,
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std::equal_to<xref:#unordered_node_map_iter_key_type[__iter-key-type__]<InputIterator>>, Allocator>;
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template<class Key, class T, class Allocator>
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unordered_node_map(std::initializer_list<std::pair<Key, T>>, typename xref:#unordered_node_map_deduction_guides[__see below__]::size_type,
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Allocator)
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-> unordered_node_map<Key, T, boost::hash<Key>, std::equal_to<Key>, Allocator>;
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template<class Key, class T, class Allocator>
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unordered_node_map(std::initializer_list<std::pair<Key, T>>, Allocator)
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-> unordered_node_map<Key, T, boost::hash<Key>, std::equal_to<Key>, Allocator>;
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template<class Key, class T, class Hash, class Allocator>
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unordered_node_map(std::initializer_list<std::pair<Key, T>>, typename xref:#unordered_node_map_deduction_guides[__see below__]::size_type,
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Hash, Allocator)
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-> unordered_node_map<Key, T, Hash, std::equal_to<Key>, Allocator>;
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// Equality Comparisons
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template<class Key, class T, class Hash, class Pred, class Alloc>
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bool xref:#unordered_node_map_operator_2[operator==](const unordered_node_map<Key, T, Hash, Pred, Alloc>& x,
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const unordered_node_map<Key, T, Hash, Pred, Alloc>& y);
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template<class Key, class T, class Hash, class Pred, class Alloc>
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bool xref:#unordered_node_map_operator_3[operator!=](const unordered_node_map<Key, T, Hash, Pred, Alloc>& x,
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const unordered_node_map<Key, T, Hash, Pred, Alloc>& y);
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// swap
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template<class Key, class T, class Hash, class Pred, class Alloc>
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void xref:#unordered_node_map_swap_2[swap](unordered_node_map<Key, T, Hash, Pred, Alloc>& x,
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unordered_node_map<Key, T, Hash, Pred, Alloc>& y)
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noexcept(noexcept(x.swap(y)));
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template<class K, class T, class H, class P, class A, class Predicate>
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typename unordered_node_map<K, T, H, P, A>::size_type
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xref:#unordered_node_map_erase_if[erase_if](unordered_node_map<K, T, H, P, A>& c, Predicate pred);
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}
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-----
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---
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=== Description
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*Template Parameters*
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[cols="1,1"]
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|===
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|_Key_
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.2+|`std::pair<const Key, T>` must be https://en.cppreference.com/w/cpp/named_req/EmplaceConstructible[EmplaceConstructible^]
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into the container from any `std::pair` object convertible to it, and it also must be
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https://en.cppreference.com/w/cpp/named_req/Erasable[Erasable^] from the container.
|
||
|
||
|_T_
|
||
|
||
|_Hash_
|
||
|A unary function object type that acts a hash function for a `Key`. It takes a single argument of type `Key` and returns a value of type `std::size_t`.
|
||
|
||
|_Pred_
|
||
|A binary function object that induces an equivalence relation on values of type `Key`. It takes two arguments of type `Key` and returns a value of type `bool`.
|
||
|
||
|_Allocator_
|
||
|An allocator whose value type is the same as the container's value type.
|
||
`std::allocator_traits<Allocator>::pointer` and `std::allocator_traits<Allocator>::const_pointer`
|
||
must be convertible to/from `value_type*` and `const value_type*`, respectively.
|
||
|
||
|===
|
||
|
||
The element nodes of the container are held into an internal _bucket array_. A node is inserted into a bucket determined by the
|
||
hash code of its element, but if the bucket is already occupied (a _collision_), an available one in the vicinity of the
|
||
original position is used.
|
||
|
||
The size of the bucket array can be automatically increased by a call to `insert`/`emplace`, or as a result of calling
|
||
`rehash`/`reserve`. The _load factor_ of the container (number of elements divided by number of buckets) is never
|
||
greater than `max_load_factor()`, except possibly for small sizes where the implementation may decide to
|
||
allow for higher loads.
|
||
|
||
If `xref:hash_traits_hash_is_avalanching[hash_is_avalanching]<Hash>::value` is `true`, the hash function
|
||
is used as-is; otherwise, a bit-mixing post-processing stage is added to increase the quality of hashing
|
||
at the expense of extra computational cost.
|
||
|
||
---
|
||
|
||
=== Typedefs
|
||
|
||
[source,c++,subs=+quotes]
|
||
----
|
||
typedef _implementation-defined_ iterator;
|
||
----
|
||
|
||
An iterator whose value type is `value_type`.
|
||
|
||
The iterator category is at least a forward iterator.
|
||
|
||
Convertible to `const_iterator`.
|
||
|
||
---
|
||
|
||
[source,c++,subs=+quotes]
|
||
----
|
||
typedef _implementation-defined_ const_iterator;
|
||
----
|
||
|
||
A constant iterator whose value type is `value_type`.
|
||
|
||
The iterator category is at least a forward iterator.
|
||
|
||
---
|
||
|
||
[source,c++,subs=+quotes]
|
||
----
|
||
typedef _implementation-defined_ node_type;
|
||
----
|
||
|
||
A class for holding extracted container elements, modelling
|
||
https://en.cppreference.com/w/cpp/container/node_handle[NodeHandle].
|
||
|
||
---
|
||
|
||
[source,c++,subs=+quotes]
|
||
----
|
||
typedef _implementation-defined_ insert_return_type;
|
||
----
|
||
|
||
A specialization of an internal class template:
|
||
|
||
[source,c++,subs=+quotes]
|
||
----
|
||
template<class Iterator, class NodeType>
|
||
struct _insert_return_type_ // name is exposition only
|
||
{
|
||
Iterator position;
|
||
bool inserted;
|
||
NodeType node;
|
||
};
|
||
----
|
||
|
||
with `Iterator` = `iterator` and `NodeType` = `node_type`.
|
||
|
||
---
|
||
|
||
=== Constructors
|
||
|
||
==== Default Constructor
|
||
```c++
|
||
unordered_node_map();
|
||
```
|
||
|
||
Constructs an empty container using `hasher()` as the hash function,
|
||
`key_equal()` as the key equality predicate and `allocator_type()` as the allocator.
|
||
|
||
[horizontal]
|
||
Postconditions:;; `size() == 0`
|
||
Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Bucket Count Constructor
|
||
```c++
|
||
explicit unordered_node_map(size_type n,
|
||
const hasher& hf = hasher(),
|
||
const key_equal& eql = key_equal(),
|
||
const allocator_type& a = allocator_type());
|
||
```
|
||
|
||
Constructs an empty container with at least `n` buckets, using `hf` as the hash
|
||
function, `eql` as the key equality predicate, and `a` as the allocator.
|
||
|
||
[horizontal]
|
||
Postconditions:;; `size() == 0`
|
||
Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Iterator Range Constructor
|
||
[source,c++,subs="+quotes"]
|
||
----
|
||
template<class InputIterator>
|
||
unordered_node_map(InputIterator f, InputIterator l,
|
||
size_type n = _implementation-defined_,
|
||
const hasher& hf = hasher(),
|
||
const key_equal& eql = key_equal(),
|
||
const allocator_type& a = allocator_type());
|
||
----
|
||
|
||
Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `eql` as the key equality predicate and `a` as the allocator, and inserts the elements from `[f, l)` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Copy Constructor
|
||
```c++
|
||
unordered_node_map(unordered_node_map const& other);
|
||
```
|
||
|
||
The copy constructor. Copies the contained elements, hash function, predicate and allocator.
|
||
|
||
If `Allocator::select_on_container_copy_construction` exists and has the right signature, the allocator will be constructed from its result.
|
||
|
||
---
|
||
|
||
==== Move Constructor
|
||
```c++
|
||
unordered_node_map(unordered_node_map&& other);
|
||
```
|
||
|
||
The move constructor. The internal bucket array of `other` is transferred directly to the new container.
|
||
The hash function, predicate and allocator are moved-constructed from `other`.
|
||
|
||
---
|
||
|
||
==== Iterator Range Constructor with Allocator
|
||
```c++
|
||
template<class InputIterator>
|
||
unordered_node_map(InputIterator f, InputIterator l, const allocator_type& a);
|
||
```
|
||
|
||
Constructs an empty container using `a` as the allocator, with the default hash function and key equality predicate and inserts the elements from `[f, l)` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; `hasher`, `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Allocator Constructor
|
||
```c++
|
||
explicit unordered_node_map(Allocator const& a);
|
||
```
|
||
|
||
Constructs an empty container, using allocator `a`.
|
||
|
||
---
|
||
|
||
==== Copy Constructor with Allocator
|
||
```c++
|
||
unordered_node_map(unordered_node_map const& other, Allocator const& a);
|
||
```
|
||
|
||
Constructs a container, copying ``other``'s contained elements, hash function, and predicate, but using allocator `a`.
|
||
|
||
---
|
||
|
||
==== Move Constructor with Allocator
|
||
```c++
|
||
unordered_node_map(unordered_node_map&& other, Allocator const& a);
|
||
```
|
||
|
||
If `a == other.get_allocator()`, the element nodes of `other` are transferred directly to the new container;
|
||
otherwise, elements are moved-constructed from those of `other`. The hash function and predicate are moved-constructed
|
||
from `other`, and the allocator is copy-constructed from `a`.
|
||
|
||
---
|
||
|
||
==== Initializer List Constructor
|
||
[source,c++,subs="+quotes"]
|
||
----
|
||
unordered_node_map(std::initializer_list<value_type> il,
|
||
size_type n = _implementation-defined_
|
||
const hasher& hf = hasher(),
|
||
const key_equal& eql = key_equal(),
|
||
const allocator_type& a = allocator_type());
|
||
----
|
||
|
||
Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `eql` as the key equality predicate and `a`, and inserts the elements from `il` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; If the defaults are used, `hasher`, `key_equal` and `allocator_type` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Bucket Count Constructor with Allocator
|
||
```c++
|
||
unordered_node_map(size_type n, allocator_type const& a);
|
||
```
|
||
|
||
Constructs an empty container with at least `n` buckets, using `hf` as the hash function, the default hash function and key equality predicate and `a` as the allocator.
|
||
|
||
[horizontal]
|
||
Postconditions:;; `size() == 0`
|
||
Requires:;; `hasher` and `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Bucket Count Constructor with Hasher and Allocator
|
||
```c++
|
||
unordered_node_map(size_type n, hasher const& hf, allocator_type const& a);
|
||
```
|
||
|
||
Constructs an empty container with at least `n` buckets, using `hf` as the hash function, the default key equality predicate and `a` as the allocator.
|
||
|
||
[horizontal]
|
||
Postconditions:;; `size() == 0`
|
||
Requires:;; `key_equal` needs to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Iterator Range Constructor with Bucket Count and Allocator
|
||
[source,c++,subs="+quotes"]
|
||
----
|
||
template<class InputIterator>
|
||
unordered_node_map(InputIterator f, InputIterator l, size_type n, const allocator_type& a);
|
||
----
|
||
|
||
Constructs an empty container with at least `n` buckets, using `a` as the allocator and default hash function and key equality predicate, and inserts the elements from `[f, l)` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; `hasher`, `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== Iterator Range Constructor with Bucket Count and Hasher
|
||
[source,c++,subs="+quotes"]
|
||
----
|
||
template<class InputIterator>
|
||
unordered_node_map(InputIterator f, InputIterator l, size_type n, const hasher& hf,
|
||
const allocator_type& a);
|
||
----
|
||
|
||
Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `a` as the allocator, with the default key equality predicate, and inserts the elements from `[f, l)` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; `key_equal` needs to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== initializer_list Constructor with Allocator
|
||
|
||
```c++
|
||
unordered_node_map(std::initializer_list<value_type> il, const allocator_type& a);
|
||
```
|
||
|
||
Constructs an empty container using `a` and default hash function and key equality predicate, and inserts the elements from `il` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; `hasher` and `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== initializer_list Constructor with Bucket Count and Allocator
|
||
|
||
```c++
|
||
unordered_node_map(std::initializer_list<value_type> il, size_type n, const allocator_type& a);
|
||
```
|
||
|
||
Constructs an empty container with at least `n` buckets, using `a` and default hash function and key equality predicate, and inserts the elements from `il` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; `hasher` and `key_equal` need to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
==== initializer_list Constructor with Bucket Count and Hasher and Allocator
|
||
|
||
```c++
|
||
unordered_node_map(std::initializer_list<value_type> il, size_type n, const hasher& hf,
|
||
const allocator_type& a);
|
||
```
|
||
|
||
Constructs an empty container with at least `n` buckets, using `hf` as the hash function, `a` as the allocator and default key equality predicate,and inserts the elements from `il` into it.
|
||
|
||
[horizontal]
|
||
Requires:;; `key_equal` needs to be https://en.cppreference.com/w/cpp/named_req/DefaultConstructible[DefaultConstructible^].
|
||
|
||
---
|
||
|
||
=== Destructor
|
||
|
||
```c++
|
||
~unordered_node_map();
|
||
```
|
||
|
||
[horizontal]
|
||
Note:;; The destructor is applied to every element, and all memory is deallocated
|
||
|
||
---
|
||
|
||
=== Assignment
|
||
|
||
==== Copy Assignment
|
||
|
||
```c++
|
||
unordered_node_map& operator=(unordered_node_map const& other);
|
||
```
|
||
|
||
The assignment operator. Destroys previously existing elements, copy-assigns the hash function and predicate from `other`,
|
||
copy-assigns the allocator from `other` if `Alloc::propagate_on_container_copy_assignment` exists and `Alloc::propagate_on_container_copy_assignment::value` is `true`,
|
||
and finally inserts copies of the elements of `other`.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^]
|
||
|
||
---
|
||
|
||
==== Move Assignment
|
||
```c++
|
||
unordered_node_map& operator=(unordered_node_map&& other)
|
||
noexcept(boost::allocator_traits<Allocator>::is_always_equal::value ||
|
||
boost::allocator_traits<Allocator>::propagate_on_container_move_assignment::value);
|
||
```
|
||
The move assignment operator. Destroys previously existing elements, swaps the hash function and predicate from `other`,
|
||
and move-assigns the allocator from `other` if `Alloc::propagate_on_container_move_assignment` exists and `Alloc::propagate_on_container_move_assignment::value` is `true`.
|
||
If at this point the allocator is equal to `other.get_allocator()`, the internal bucket array of `other` is transferred directly to the new container;
|
||
otherwise, inserts move-constructed copies of the elements of `other`.
|
||
|
||
---
|
||
|
||
==== Initializer List Assignment
|
||
```c++
|
||
unordered_node_map& operator=(std::initializer_list<value_type> il);
|
||
```
|
||
|
||
Assign from values in initializer list. All previously existing elements are destroyed.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^]
|
||
|
||
=== Iterators
|
||
|
||
==== begin
|
||
```c++
|
||
iterator begin() noexcept;
|
||
const_iterator begin() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; An iterator referring to the first element of the container, or if the container is empty the past-the-end value for the container.
|
||
Complexity:;; O(`bucket_count()`)
|
||
|
||
---
|
||
|
||
==== end
|
||
```c++
|
||
iterator end() noexcept;
|
||
const_iterator end() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; An iterator which refers to the past-the-end value for the container.
|
||
|
||
---
|
||
|
||
==== cbegin
|
||
```c++
|
||
const_iterator cbegin() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; A `const_iterator` referring to the first element of the container, or if the container is empty the past-the-end value for the container.
|
||
Complexity:;; O(`bucket_count()`)
|
||
|
||
---
|
||
|
||
==== cend
|
||
```c++
|
||
const_iterator cend() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; A `const_iterator` which refers to the past-the-end value for the container.
|
||
|
||
---
|
||
|
||
=== Size and Capacity
|
||
|
||
==== empty
|
||
|
||
```c++
|
||
[[nodiscard]] bool empty() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; `size() == 0`
|
||
|
||
---
|
||
|
||
==== size
|
||
|
||
```c++
|
||
size_type size() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; `std::distance(begin(), end())`
|
||
|
||
---
|
||
|
||
==== max_size
|
||
|
||
```c++
|
||
size_type max_size() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; `size()` of the largest possible container.
|
||
|
||
---
|
||
|
||
=== Modifiers
|
||
|
||
==== emplace
|
||
```c++
|
||
template<class... Args> std::pair<iterator, bool> emplace(Args&&... args);
|
||
```
|
||
|
||
Inserts an object, constructed with the arguments `args`, in the container if and only if there is no element in the container with an equivalent key.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is constructible from `args`.
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
|
||
---
|
||
|
||
==== emplace_hint
|
||
```c++
|
||
template<class... Args> iterator emplace_hint(const_iterator position, Args&&... args);
|
||
```
|
||
|
||
Inserts an object, constructed with the arguments `args`, in the container if and only if there is no element in the container with an equivalent key.
|
||
|
||
`position` is a suggestion to where the element should be inserted. This implementation ignores it.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is constructible from `args`.
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
|
||
---
|
||
|
||
==== Copy Insert
|
||
```c++
|
||
std::pair<iterator, bool> insert(const value_type& obj);
|
||
std::pair<iterator, bool> insert(const init_type& obj);
|
||
```
|
||
|
||
Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^].
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
+
|
||
A call of the form `insert(x)`, where `x` is equally convertible to both `const value_type&` and `const init_type&`, is not ambiguous and selects the `init_type` overload.
|
||
|
||
---
|
||
|
||
==== Move Insert
|
||
```c++
|
||
std::pair<iterator, bool> insert(value_type&& obj);
|
||
std::pair<iterator, bool> insert(init_type&& obj);
|
||
```
|
||
|
||
Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/MoveInsertable[MoveInsertable^].
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
+
|
||
A call of the form `insert(x)`, where `x` is equally convertible to both `value_type&&` and `init_type&&`, is not ambiguous and selects the `init_type` overload.
|
||
|
||
---
|
||
|
||
==== Copy Insert with Hint
|
||
```c++
|
||
iterator insert(const_iterator hint, const value_type& obj);
|
||
iterator insert(const_iterator hint, const init_type& obj);
|
||
```
|
||
Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
|
||
|
||
`hint` is a suggestion to where the element should be inserted. This implementation ignores it.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/CopyInsertable[CopyInsertable^].
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
+
|
||
A call of the form `insert(hint, x)`, where `x` is equally convertible to both `const value_type&` and `const init_type&`, is not ambiguous and selects the `init_type` overload.
|
||
|
||
---
|
||
|
||
==== Move Insert with Hint
|
||
```c++
|
||
iterator insert(const_iterator hint, value_type&& obj);
|
||
iterator insert(const_iterator hint, init_type&& obj);
|
||
```
|
||
|
||
Inserts `obj` in the container if and only if there is no element in the container with an equivalent key.
|
||
|
||
`hint` is a suggestion to where the element should be inserted. This implementation ignores it.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/MoveInsertable[MoveInsertable^].
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
+
|
||
A call of the form `insert(hint, x)`, where `x` is equally convertible to both `value_type&&` and `init_type&&`, is not ambiguous and selects the `init_type` overload.
|
||
|
||
---
|
||
|
||
==== Insert Iterator Range
|
||
```c++
|
||
template<class InputIterator> void insert(InputIterator first, InputIterator last);
|
||
```
|
||
|
||
Inserts a range of elements into the container. Elements are inserted if and only if there is no element in the container with an equivalent key.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/EmplaceConstructible[EmplaceConstructible^] into the container from `*first`.
|
||
Throws:;; When inserting a single element, if an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
|
||
|
||
---
|
||
|
||
==== Insert Initializer List
|
||
```c++
|
||
void insert(std::initializer_list<value_type>);
|
||
```
|
||
|
||
Inserts a range of elements into the container. Elements are inserted if and only if there is no element in the container with an equivalent key.
|
||
|
||
[horizontal]
|
||
Requires:;; `value_type` is https://en.cppreference.com/w/cpp/named_req/EmplaceConstructible[EmplaceConstructible^] into the container from `*first`.
|
||
Throws:;; When inserting a single element, if an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
|
||
|
||
---
|
||
|
||
==== Insert Node
|
||
```c++
|
||
insert_return_type insert(node_type&& nh);
|
||
```
|
||
|
||
If `nh` is not empty, inserts the associated element in the container if and only if there is no element in the container with a key equivalent to `nh.key()`.
|
||
`nh` is empty when the function returns.
|
||
|
||
[horizontal]
|
||
Returns:;; An `insert_return_type` object constructed from `position`, `inserted` and `node`: +
|
||
* If `nh` is empty, `inserted` is `false`, `position` is `end()`, and `node` is empty.
|
||
* Otherwise if the insertion took place, `inserted` is true, `position` points to the inserted element, and `node` is empty.
|
||
* If the insertion failed, `inserted` is false, `node` has the previous value of `nh`, and `position` points to an element with a key equivalent to `nh.key()`.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Behavior is undefined if `nh` is not empty and the allocators of `nh` and the container are not equal.
|
||
|
||
---
|
||
|
||
==== Insert Node with Hint
|
||
```c++
|
||
iterator insert(const_iterator hint, node_type&& nh);
|
||
```
|
||
|
||
If `nh` is not empty, inserts the associated element in the container if and only if there is no element in the container with a key equivalent to `nh.key()`.
|
||
`nh` becomes empty if insertion took place, otherwise it is not changed.
|
||
|
||
`hint` is a suggestion to where the element should be inserted. This implementation ignores it.
|
||
|
||
[horizontal]
|
||
Returns:;; The iterator returned is `end()` if `nh` is empty.
|
||
If insertion took place, then the iterator points to the newly inserted element; otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Behavior is undefined if `nh` is not empty and the allocators of `nh` and the container are not equal.
|
||
|
||
---
|
||
|
||
==== try_emplace
|
||
```c++
|
||
template<class... Args>
|
||
std::pair<iterator, bool> try_emplace(const key_type& k, Args&&... args);
|
||
template<class... Args>
|
||
std::pair<iterator, bool> try_emplace(key_type&& k, Args&&... args);
|
||
template<class K, class... Args>
|
||
std::pair<iterator, bool> try_emplace(K&& k, Args&&... args);
|
||
```
|
||
|
||
Inserts a new node into the container if there is no existing element with key `k` contained within it.
|
||
|
||
If there is an existing element with key `k` this function does nothing.
|
||
|
||
[horizontal]
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; This function is similiar to xref:#unordered_node_map_emplace[emplace], with the difference that no `value_type` is constructed
|
||
if there is an element with an equivalent key; otherwise, the construction is of the form: +
|
||
+
|
||
--
|
||
```c++
|
||
// first two overloads
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<Key>(k)),
|
||
std::forward_as_tuple(boost::forward<Args>(args)...))
|
||
|
||
// third overload
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<K>(k)),
|
||
std::forward_as_tuple(boost::forward<Args>(args)...))
|
||
```
|
||
|
||
unlike xref:#unordered_node_map_emplace[emplace], which simply forwards all arguments to ``value_type``'s constructor.
|
||
|
||
Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
|
||
|
||
The `template <class K, class... Args>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs and neither `iterator` nor `const_iterator` are implicitly convertible from `K`. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
--
|
||
|
||
---
|
||
|
||
==== try_emplace with Hint
|
||
```c++
|
||
template<class... Args>
|
||
iterator try_emplace(const_iterator hint, const key_type& k, Args&&... args);
|
||
template<class... Args>
|
||
iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args);
|
||
template<class K, class... Args>
|
||
iterator try_emplace(const_iterator hint, K&& k, Args&&... args);
|
||
```
|
||
|
||
Inserts a new node into the container if there is no existing element with key `k` contained within it.
|
||
|
||
If there is an existing element with key `k` this function does nothing.
|
||
|
||
`hint` is a suggestion to where the element should be inserted. This implementation ignores it.
|
||
|
||
[horizontal]
|
||
Returns:;; If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; This function is similiar to xref:#unordered_node_map_emplace_hint[emplace_hint], with the difference that no `value_type` is constructed
|
||
if there is an element with an equivalent key; otherwise, the construction is of the form: +
|
||
+
|
||
--
|
||
```c++
|
||
// first two overloads
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<Key>(k)),
|
||
std::forward_as_tuple(boost::forward<Args>(args)...))
|
||
|
||
// third overload
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<K>(k)),
|
||
std::forward_as_tuple(boost::forward<Args>(args)...))
|
||
```
|
||
|
||
unlike xref:#unordered_node_map_emplace_hint[emplace_hint], which simply forwards all arguments to ``value_type``'s constructor.
|
||
|
||
Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load.
|
||
|
||
The `template <class K, class... Args>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs and neither `iterator` nor `const_iterator` are implicitly convertible from `K`. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
--
|
||
|
||
---
|
||
|
||
==== insert_or_assign
|
||
```c++
|
||
template<class M>
|
||
std::pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj);
|
||
template<class M>
|
||
std::pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj);
|
||
template<class K, class M>
|
||
std::pair<iterator, bool> insert_or_assign(K&& k, M&& obj);
|
||
```
|
||
|
||
Inserts a new element into the container or updates an existing one by assigning to the contained value.
|
||
|
||
If there is an element with key `k`, then it is updated by assigning `boost::forward<M>(obj)`.
|
||
|
||
If there is no such element, it is added to the container as:
|
||
```c++
|
||
// first two overloads
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<Key>(k)),
|
||
std::forward_as_tuple(boost::forward<M>(obj)))
|
||
|
||
// third overload
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<K>(k)),
|
||
std::forward_as_tuple(boost::forward<M>(obj)))
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; The `bool` component of the return type is `true` if an insert took place. +
|
||
+
|
||
If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
+
|
||
The `template<class K, class M>` only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== insert_or_assign with Hint
|
||
```c++
|
||
template<class M>
|
||
iterator insert_or_assign(const_iterator hint, const key_type& k, M&& obj);
|
||
template<class M>
|
||
iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj);
|
||
template<class K, class M>
|
||
iterator insert_or_assign(const_iterator hint, K&& k, M&& obj);
|
||
```
|
||
|
||
Inserts a new element into the container or updates an existing one by assigning to the contained value.
|
||
|
||
If there is an element with key `k`, then it is updated by assigning `boost::forward<M>(obj)`.
|
||
|
||
If there is no such element, it is added to the container as:
|
||
```c++
|
||
// first two overloads
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<Key>(k)),
|
||
std::forward_as_tuple(boost::forward<M>(obj)))
|
||
|
||
// third overload
|
||
value_type(std::piecewise_construct,
|
||
std::forward_as_tuple(boost::forward<K>(k)),
|
||
std::forward_as_tuple(boost::forward<M>(obj)))
|
||
```
|
||
|
||
`hint` is a suggestion to where the element should be inserted. This implementation ignores it.
|
||
|
||
[horizontal]
|
||
Returns:;; If an insert took place, then the iterator points to the newly inserted element. Otherwise, it points to the element with equivalent key.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
+
|
||
The `template<class K, class M>` only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
|
||
==== Erase by Position
|
||
|
||
```c++
|
||
void erase(iterator position);
|
||
void erase(const_iterator position);
|
||
```
|
||
|
||
Erase the element pointed to by `position`.
|
||
|
||
[horizontal]
|
||
Throws:;; Nothing.
|
||
|
||
---
|
||
|
||
==== Erase by Key
|
||
```c++
|
||
size_type erase(const key_type& k);
|
||
template<class K> size_type erase(K&& k);
|
||
```
|
||
|
||
Erase all elements with key equivalent to `k`.
|
||
|
||
[horizontal]
|
||
Returns:;; The number of elements erased.
|
||
Throws:;; Only throws an exception if it is thrown by `hasher` or `key_equal`.
|
||
Notes:;; The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs and neither `iterator` nor `const_iterator` are implicitly convertible from `K`. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== Erase Range
|
||
|
||
```c++
|
||
iterator erase(const_iterator first, const_iterator last);
|
||
```
|
||
|
||
Erases the elements in the range from `first` to `last`.
|
||
|
||
[horizontal]
|
||
Returns:;; The iterator following the erased elements - i.e. `last`.
|
||
Throws:;; Nothing in this implementation (neither the `hasher` nor the `key_equal` objects are called).
|
||
|
||
---
|
||
|
||
==== swap
|
||
```c++
|
||
void swap(unordered_node_map& other)
|
||
noexcept(boost::allocator_traits<Allocator>::is_always_equal::value ||
|
||
boost::allocator_traits<Allocator>::propagate_on_container_swap::value);
|
||
```
|
||
|
||
Swaps the contents of the container with the parameter.
|
||
|
||
If `Allocator::propagate_on_container_swap` is declared and `Allocator::propagate_on_container_swap::value` is `true` then the containers' allocators are swapped. Otherwise, swapping with unequal allocators results in undefined behavior.
|
||
|
||
[horizontal]
|
||
Throws:;; Nothing unless `key_equal` or `hasher` throw on swapping.
|
||
|
||
---
|
||
|
||
==== Extract by Position
|
||
```c++
|
||
node_type extract(const_iterator position);
|
||
```
|
||
|
||
Extracts the element pointed to by `position`.
|
||
|
||
[horizontal]
|
||
Returns:;; A `node_type` object holding the extracted element.
|
||
Throws:;; Nothing.
|
||
|
||
---
|
||
|
||
==== Extract by Key
|
||
```c++
|
||
node_type erase(const key_type& k);
|
||
template<class K> node_type erase(K&& k);
|
||
```
|
||
|
||
Extracts the element with key equivalent to `k`, if it exists.
|
||
|
||
[horizontal]
|
||
Returns:;; A `node_type` object holding the extracted element, or empty if no element was extracted.
|
||
Throws:;; Only throws an exception if it is thrown by `hasher` or `key_equal`.
|
||
Notes:;; The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs and neither `iterator` nor `const_iterator` are implicitly convertible from `K`. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== clear
|
||
```c++
|
||
void clear() noexcept;
|
||
```
|
||
|
||
Erases all elements in the container.
|
||
|
||
[horizontal]
|
||
Postconditions:;; `size() == 0`, `max_load() >= max_load_factor() * bucket_count()`
|
||
|
||
---
|
||
|
||
==== merge
|
||
```c++
|
||
template<class H2, class P2>
|
||
void merge(unordered_node_map<Key, T, H2, P2, Allocator>& source);
|
||
template<class H2, class P2>
|
||
void merge(unordered_node_map<Key, T, H2, P2, Allocator>&& source);
|
||
```
|
||
|
||
Transfers all the element nodes from `source` whose key is not already present in `*this`.
|
||
|
||
---
|
||
|
||
=== Observers
|
||
|
||
==== get_allocator
|
||
```
|
||
allocator_type get_allocator() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; The container's allocator.
|
||
|
||
---
|
||
|
||
==== hash_function
|
||
```
|
||
hasher hash_function() const;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; The container's hash function.
|
||
|
||
---
|
||
|
||
==== key_eq
|
||
```
|
||
key_equal key_eq() const;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; The container's key equality predicate
|
||
|
||
---
|
||
|
||
=== Lookup
|
||
|
||
==== find
|
||
```c++
|
||
iterator find(const key_type& k);
|
||
const_iterator find(const key_type& k) const;
|
||
template<class K>
|
||
iterator find(const K& k);
|
||
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; An iterator pointing to an element with key equivalent to `k`, or `end()` if no such element exists.
|
||
Notes:;; The `template <typename K>` overloads only participate in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== count
|
||
```c++
|
||
size_type count(const key_type& k) const;
|
||
template<class K>
|
||
size_type count(const K& k) const;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; The number of elements with key equivalent to `k`.
|
||
Notes:;; The `template <typename K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== contains
|
||
```c++
|
||
bool contains(const key_type& k) const;
|
||
template<class K>
|
||
bool contains(const K& k) const;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; A boolean indicating whether or not there is an element with key equal to `key` in the container
|
||
Notes:;; The `template <typename K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== equal_range
|
||
```c++
|
||
std::pair<iterator, iterator> equal_range(const key_type& k);
|
||
std::pair<const_iterator, const_iterator> equal_range(const key_type& k) const;
|
||
template<class K>
|
||
std::pair<iterator, iterator> equal_range(const K& k);
|
||
template<class K>
|
||
std::pair<const_iterator, const_iterator> equal_range(const K& k) const;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; A range containing all elements with key equivalent to `k`. If the container doesn't contain any such elements, returns `std::make_pair(b.end(), b.end())`.
|
||
Notes:;; The `template <typename K>` overloads only participate in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== operator++[++++]++
|
||
```c++
|
||
mapped_type& operator[](const key_type& k);
|
||
mapped_type& operator[](key_type&& k);
|
||
template<class K> mapped_type& operator[](K&& k);
|
||
```
|
||
|
||
[horizontal]
|
||
Effects:;; If the container does not already contain an element with a key equivalent to `k`, inserts the value `std::pair<key_type const, mapped_type>(k, mapped_type())`.
|
||
Returns:;; A reference to `x.second` where `x` is the element already in the container, or the newly inserted element with a key equivalent to `k`.
|
||
Throws:;; If an exception is thrown by an operation other than a call to `hasher` the function has no effect.
|
||
Notes:;; Can invalidate iterators, but only if the insert causes the load to be greater than the maximum load. +
|
||
+
|
||
The `template<class K>` overload only participates in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
==== at
|
||
```c++
|
||
mapped_type& at(const key_type& k);
|
||
const mapped_type& at(const key_type& k) const;
|
||
template<class K> mapped_type& at(const K& k);
|
||
template<class K> const mapped_type& at(const K& k) const;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; A reference to `x.second` where `x` is the (unique) element whose key is equivalent to `k`.
|
||
Throws:;; An exception object of type `std::out_of_range` if no such element is present.
|
||
Notes:;; The `template<class K>` overloads only participate in overload resolution if `Hash::is_transparent` and `Pred::is_transparent` are valid member typedefs. The library assumes that `Hash` is callable with both `K` and `Key` and that `Pred` is transparent. This enables heterogeneous lookup which avoids the cost of instantiating an instance of the `Key` type.
|
||
|
||
---
|
||
|
||
=== Bucket Interface
|
||
|
||
==== bucket_count
|
||
```c++
|
||
size_type bucket_count() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; The size of the bucket array.
|
||
|
||
---
|
||
|
||
=== Hash Policy
|
||
|
||
==== load_factor
|
||
```c++
|
||
float load_factor() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; `static_cast<float>(size())/static_cast<float>(bucket_count())`, or `0` if `bucket_count() == 0`.
|
||
|
||
---
|
||
|
||
==== max_load_factor
|
||
|
||
```c++
|
||
float max_load_factor() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; Returns the container's maximum load factor.
|
||
|
||
---
|
||
|
||
==== Set max_load_factor
|
||
```c++
|
||
void max_load_factor(float z);
|
||
```
|
||
|
||
[horizontal]
|
||
Effects:;; Does nothing, as the user is not allowed to change this parameter. Kept for compatibility with `boost::unordered_map`.
|
||
|
||
---
|
||
|
||
|
||
==== max_load
|
||
|
||
```c++
|
||
size_type max_load() const noexcept;
|
||
```
|
||
|
||
[horizontal]
|
||
Returns:;; The maximum number of elements the container can hold without rehashing, assuming that no further elements will be erased.
|
||
Note:;; After construction, rehash or clearance, the container's maximum load is at least `max_load_factor() * bucket_count()`.
|
||
This number may decrease on erasure under high-load conditions.
|
||
|
||
---
|
||
|
||
==== rehash
|
||
```c++
|
||
void rehash(size_type n);
|
||
```
|
||
|
||
Changes if necessary the size of the bucket array so that there are at least `n` buckets, and so that the load factor is less than or equal to the maximum load factor. When applicable, this will either grow or shrink the `bucket_count()` associated with the container.
|
||
|
||
When `size() == 0`, `rehash(0)` will deallocate the underlying buckets array.
|
||
|
||
Invalidates iterators and changes the order of elements.
|
||
|
||
[horizontal]
|
||
Throws:;; The function has no effect if an exception is thrown, unless it is thrown by the container's hash function or comparison function.
|
||
|
||
---
|
||
|
||
==== reserve
|
||
```c++
|
||
void reserve(size_type n);
|
||
```
|
||
|
||
Equivalent to `a.rehash(ceil(n / a.max_load_factor()))`.
|
||
|
||
Similar to `rehash`, this function can be used to grow or shrink the number of buckets in the container.
|
||
|
||
Invalidates iterators and changes the order of elements.
|
||
|
||
[horizontal]
|
||
Throws:;; The function has no effect if an exception is thrown, unless it is thrown by the container's hash function or comparison function.
|
||
|
||
=== Deduction Guides
|
||
A deduction guide will not participate in overload resolution if any of the following are true:
|
||
|
||
- It has an `InputIterator` template parameter and a type that does not qualify as an input iterator is deduced for that parameter.
|
||
- It has an `Allocator` template parameter and a type that does not qualify as an allocator is deduced for that parameter.
|
||
- It has a `Hash` template parameter and an integral type or a type that qualifies as an allocator is deduced for that parameter.
|
||
- It has a `Pred` template parameter and a type that qualifies as an allocator is deduced for that parameter.
|
||
|
||
A `size_type` parameter type in a deduction guide refers to the `size_type` member type of the
|
||
container type deduced by the deduction guide. Its default value coincides with the default value
|
||
of the constructor selected.
|
||
|
||
==== __iter-value-type__
|
||
[listings,subs="+macros,+quotes"]
|
||
-----
|
||
template<class InputIterator>
|
||
using __iter-value-type__ =
|
||
typename std::iterator_traits<InputIterator>::value_type; // exposition only
|
||
-----
|
||
|
||
==== __iter-key-type__
|
||
[listings,subs="+macros,+quotes"]
|
||
-----
|
||
template<class InputIterator>
|
||
using __iter-key-type__ = std::remove_const_t<
|
||
std::tuple_element_t<0, xref:#unordered_map_iter_value_type[__iter-value-type__]<InputIterator>>>; // exposition only
|
||
-----
|
||
|
||
==== __iter-mapped-type__
|
||
[listings,subs="+macros,+quotes"]
|
||
-----
|
||
template<class InputIterator>
|
||
using __iter-mapped-type__ =
|
||
std::tuple_element_t<1, xref:#unordered_map_iter_value_type[__iter-value-type__]<InputIterator>>; // exposition only
|
||
-----
|
||
|
||
==== __iter-to-alloc-type__
|
||
[listings,subs="+macros,+quotes"]
|
||
-----
|
||
template<class InputIterator>
|
||
using __iter-to-alloc-type__ = std::pair<
|
||
std::add_const_t<std::tuple_element_t<0, xref:#unordered_map_iter_value_type[__iter-value-type__]<InputIterator>>>,
|
||
std::tuple_element_t<1, xref:#unordered_map_iter_value_type[__iter-value-type__]<InputIterator>>>; // exposition only
|
||
-----
|
||
|
||
=== Equality Comparisons
|
||
|
||
==== operator==
|
||
```c++
|
||
template<class Key, class T, class Hash, class Pred, class Alloc>
|
||
bool operator==(const unordered_node_map<Key, T, Hash, Pred, Alloc>& x,
|
||
const unordered_node_map<Key, T, Hash, Pred, Alloc>& y);
|
||
```
|
||
|
||
Return `true` if `x.size() == y.size()` and for every element in `x`, there is an element in `y` with the same key, with an equal value (using `operator==` to compare the value types).
|
||
|
||
[horizontal]
|
||
Notes:;; Behavior is undefined if the two containers don't have equivalent equality predicates.
|
||
|
||
---
|
||
|
||
==== operator!=
|
||
```c++
|
||
template<class Key, class T, class Hash, class Pred, class Alloc>
|
||
bool operator!=(const unordered_node_map<Key, T, Hash, Pred, Alloc>& x,
|
||
const unordered_node_map<Key, T, Hash, Pred, Alloc>& y);
|
||
```
|
||
|
||
Return `false` if `x.size() == y.size()` and for every element in `x`, there is an element in `y` with the same key, with an equal value (using `operator==` to compare the value types).
|
||
|
||
[horizontal]
|
||
Notes:;; Behavior is undefined if the two containers don't have equivalent equality predicates.
|
||
|
||
=== Swap
|
||
```c++
|
||
template<class Key, class T, class Hash, class Pred, class Alloc>
|
||
void swap(unordered_node_map<Key, T, Hash, Pred, Alloc>& x,
|
||
unordered_node_map<Key, T, Hash, Pred, Alloc>& y)
|
||
noexcept(noexcept(x.swap(y)));
|
||
```
|
||
|
||
Swaps the contents of `x` and `y`.
|
||
|
||
If `Allocator::propagate_on_container_swap` is declared and `Allocator::propagate_on_container_swap::value` is `true` then the containers' allocators are swapped. Otherwise, swapping with unequal allocators results in undefined behavior.
|
||
|
||
[horizontal]
|
||
Effects:;; `x.swap(y)`
|
||
Throws:;; Nothing unless `key_equal` or `hasher` throw on swapping.
|
||
|
||
---
|
||
|
||
=== erase_if
|
||
```c++
|
||
template<class K, class T, class H, class P, class A, class Predicate>
|
||
typename unordered_node_map<K, T, H, P, A>::size_type
|
||
erase_if(unordered_node_map<K, T, H, P, A>& c, Predicate pred);
|
||
```
|
||
|
||
Traverses the container `c` and removes all elements for which the supplied predicate returns `true`.
|
||
|
||
[horizontal]
|
||
Returns:;; The number of erased elements.
|
||
Notes:;; Equivalent to: +
|
||
+
|
||
```c++
|
||
auto original_size = c.size();
|
||
for (auto i = c.begin(), last = c.end(); i != last; ) {
|
||
if (pred(*i)) {
|
||
i = c.erase(i);
|
||
} else {
|
||
++i;
|
||
}
|
||
}
|
||
return original_size - c.size();
|
||
```
|
||
|
||
---
|