标准库头文件 <map>
来自 cppreference.com
此头文件是 容器 库的一部分。
包含 | ||
(C++20) |
三路比较运算符 支持 | |
(C++11) |
std::initializer_list 类模板 | |
类 | ||
键值对集合,按键排序,键唯一 (类模板) | ||
键值对集合,按键排序 (类模板) | ||
函数 | ||
(C++20 中移除)(C++20 中移除)(C++20 中移除)(C++20 中移除)(C++20 中移除)(C++20) |
按字典序比较两个 map 的值(函数模板) | |
专门化 std::swap 算法 (函数模板) | ||
(C++20) |
删除所有满足特定条件的元素 (函数模板) | |
(C++20 中移除)(C++20 中移除)(C++20 中移除)(C++20 中移除)(C++20 中移除)(C++20) |
按字典序比较两个 multimap 的值(函数模板) | |
专门化 std::swap 算法 (函数模板) | ||
(C++20) |
删除所有满足特定条件的元素 (函数模板) | |
范围访问 | ||
(C++11)(C++14) |
返回指向容器或数组开头的迭代器 (函数模板) | |
(C++11)(C++14) |
返回指向容器或数组末尾的迭代器 (函数模板) | |
(C++14) |
返回指向容器或数组开头的反向迭代器 (函数模板) | |
(C++14) |
返回容器或数组的反向末尾迭代器 (函数模板) | |
(C++17)(C++20) |
返回容器或数组的大小 (函数模板) | |
(C++17) |
检查容器是否为空 (函数模板) | |
(C++17) |
获取指向底层数组的指针 (函数模板) |
[编辑] 概要
#include <compare> #include <initializer_list> namespace std { // class template map template<class Key, class T, class Compare = less<Key>, class Allocator = allocator<pair<const Key, T>>> class map; template<class Key, class T, class Compare, class Allocator> bool operator==(const map<Key, T, Compare, Allocator>& x, const map<Key, T, Compare, Allocator>& y); template<class Key, class T, class Compare, class Allocator> /*synth-three-way-result*/<pair<const Key, T>> operator<=>( const map<Key, T, Compare, Allocator>& x, const map<Key, T, Compare, Allocator>& y); template<class Key, class T, class Compare, class Allocator> void swap(map<Key, T, Compare, Allocator>& x, map<Key, T, Compare, Allocator>& y) noexcept(noexcept(x.swap(y))); // erasure for map template<class Key, class T, class Compare, class Allocator, class Predicate> typename map<Key, T, Compare, Allocator>::size_type erase_if( map<Key, T, Compare, Allocator>& c, Predicate pred); // class template multimap template<class Key, class T, class Compare = less<Key>, class Allocator = allocator<pair<const Key, T>>> class multimap; template<class Key, class T, class Compare, class Allocator> bool operator==(const multimap<Key, T, Compare, Allocator>& x, const multimap<Key, T, Compare, Allocator>& y); template<class Key, class T, class Compare, class Allocator> /*synth-three-way-result*/<pair<const Key, T>> operator<=>( const multimap<Key, T, Compare, Allocator>& x, const multimap<Key, T, Compare, Allocator>& y); template<class Key, class T, class Compare, class Allocator> void swap(multimap<Key, T, Compare, Allocator>& x, multimap<Key, T, Compare, Allocator>& y) noexcept(noexcept(x.swap(y))); // erasure for multimap template<class Key, class T, class Compare, class Allocator, class Predicate> typename multimap<Key, T, Compare, Allocator>::size_type erase_if( multimap<Key, T, Compare, Allocator>& c, Predicate pred); namespace pmr { template<class Key, class T, class Compare = less<Key>> using map = std::map<Key, T, Compare, polymorphic_allocator<pair<const Key, T>>>; template<class Key, class T, class Compare = less<Key>> using multimap = std::multimap<Key, T, Compare, polymorphic_allocator<pair<const Key, T>>>; } }
[编辑] 类模板 std::map
namespace std { template<class Key, class T, class Compare = less<Key>, class Allocator = allocator<pair<const Key, T>>> class map { public: // types using key_type = Key; using mapped_type = T; using value_type = pair<const Key, T>; using key_compare = Compare; using allocator_type = Allocator; using pointer = typename allocator_traits<Allocator>::pointer; using const_pointer = typename allocator_traits<Allocator>::const_pointer; using reference = value_type&; using const_reference = const value_type&; using size_type = /* implementation-defined */; using difference_type = /* implementation-defined */; using iterator = /* implementation-defined */; using const_iterator = /* implementation-defined */; using reverse_iterator = std::reverse_iterator<iterator>; using const_reverse_iterator = std::reverse_iterator<const_iterator>; using node_type = /* unspecified */; using insert_return_type = /*insert-return-type*/<iterator, node_type>; class value_compare { protected: Compare comp; value_compare(Compare c) : comp(c) { } public: bool operator()(const value_type& x, const value_type& y) const { return comp(x.first, y.first); } }; // construct/copy/destroy map() : map(Compare()) { } explicit map(const Compare& comp, const Allocator& = Allocator()); template<class InputIter> map(InputIter first, InputIter last, const Compare& comp = Compare(), const Allocator& = Allocator()); template<container-compatible-range<value_type> R> map(from_range_t, R&& rg, const Compare& comp = Compare(), const Allocator& = Allocator()); map(const map& x); map(map&& x); explicit map(const Allocator&); map(const map&, const type_identity_t<Allocator>&); map(map&&, const type_identity_t<Allocator>&); map(initializer_list<value_type>, const Compare& = Compare(), const Allocator& = Allocator()); template<class InputIter> map(InputIter first, InputIter last, const Allocator& a) : map(first, last, Compare(), a) { } template<container-compatible-range<value_type> R> map(from_range_t, R&& rg, const Allocator& a)) : map(from_range, std::forward<R>(rg), Compare(), a) { } map(initializer_list<value_type> il, const Allocator& a) : map(il, Compare(), a) { } ~map(); map& operator=(const map& x); map& operator=(map&& x) noexcept(allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_move_assignable_v<Compare>); map& operator=(initializer_list<value_type>); allocator_type get_allocator() const noexcept; // iterators iterator begin() noexcept; const_iterator begin() const noexcept; iterator end() noexcept; const_iterator end() const noexcept; reverse_iterator rbegin() noexcept; const_reverse_iterator rbegin() const noexcept; reverse_iterator rend() noexcept; const_reverse_iterator rend() const noexcept; const_iterator cbegin() const noexcept; const_iterator cend() const noexcept; const_reverse_iterator crbegin() const noexcept; const_reverse_iterator crend() const noexcept; // capacity bool empty() const noexcept; size_type size() const noexcept; size_type max_size() const noexcept; // element access mapped_type& operator[](const key_type& x); mapped_type& operator[](key_type&& x); template<class K> mapped_type& operator[](K&& x); mapped_type& at(const key_type& x); const mapped_type& at(const key_type& x) const; template<class K> mapped_type& at(const K& x); template<class K> const mapped_type& at(const K& x) const; // modifiers template<class... Args> pair<iterator, bool> emplace(Args&&... args); template<class... Args> iterator emplace_hint(const_iterator position, Args&&... args); pair<iterator, bool> insert(const value_type& x); pair<iterator, bool> insert(value_type&& x); template<class P> pair<iterator, bool> insert(P&& x); iterator insert(const_iterator position, const value_type& x); iterator insert(const_iterator position, value_type&& x); template<class P> iterator insert(const_iterator position, P&&); template<class InputIter> void insert(InputIter first, InputIter last); template<container-compatible-range<value_type> R> void insert_range(R&& rg); void insert(initializer_list<value_type>); node_type extract(const_iterator position); node_type extract(const key_type& x); template<class K> node_type extract(K&& x); insert_return_type insert(node_type&& nh); iterator insert(const_iterator hint, node_type&& nh); template<class... Args> pair<iterator, bool> try_emplace(const key_type& k, Args&&... args); template<class... Args> pair<iterator, bool> try_emplace(key_type&& k, Args&&... args); template<class K, class... Args> pair<iterator, bool> try_emplace(K&& k, Args&&... args); 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); template<class M> pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj); template<class M> pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj); template<class K, class M> pair<iterator, bool> insert_or_assign(K&& k, M&& obj); 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); iterator erase(iterator position); iterator erase(const_iterator position); size_type erase(const key_type& x); template<class K> size_type erase(K&& x); iterator erase(const_iterator first, const_iterator last); void swap(map&) noexcept(allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_swappable_v<Compare>); void clear() noexcept; template<class C2> void merge(map<Key, T, C2, Allocator>& source); template<class C2> void merge(map<Key, T, C2, Allocator>&& source); template<class C2> void merge(multimap<Key, T, C2, Allocator>& source); template<class C2> void merge(multimap<Key, T, C2, Allocator>&& source); // observers key_compare key_comp() const; value_compare value_comp() const; // map operations iterator find(const key_type& x); const_iterator find(const key_type& x) const; template<class K> iterator find(const K& x); template<class K> const_iterator find(const K& x) const; size_type count(const key_type& x) const; template<class K> size_type count(const K& x) const; bool contains(const key_type& x) const; template<class K> bool contains(const K& x) const; iterator lower_bound(const key_type& x); const_iterator lower_bound(const key_type& x) const; template<class K> iterator lower_bound(const K& x); template<class K> const_iterator lower_bound(const K& x) const; iterator upper_bound(const key_type& x); const_iterator upper_bound(const key_type& x) const; template<class K> iterator upper_bound(const K& x); template<class K> const_iterator upper_bound(const K& x) const; pair<iterator, iterator> equal_range(const key_type& x); pair<const_iterator, const_iterator> equal_range(const key_type& x) const; template<class K> pair<iterator, iterator> equal_range(const K& x); template<class K> pair<const_iterator, const_iterator> equal_range(const K& x) const; }; template<class InputIter, class Compare = less</*iter-key-type*/<InputIter>>, class Allocator = allocator</*iter-to-alloc-type*/<InputIter>>> map(InputIter, InputIter, Compare = Compare(), Allocator = Allocator()) -> map</*iter-key-type*/<InputIter>, /*iter-mapped-type*/<InputIter>, Compare, Allocator>; template< ranges::input_range R, class Compare = less</*range-key-type*/<R>, class Allocator = allocator</*range-to-alloc-type*/<R>>> map(from_range_t, R&&, Compare = Compare(), Allocator = Allocator()) -> map</*range-key-type*/<R>, /*range-mapped-type*/<R>, Compare, Allocator>; template<class Key, class T, class Compare = less<Key>, class Allocator = allocator<pair<const Key, T>>> map(initializer_list<pair<Key, T>>, Compare = Compare(), Allocator = Allocator()) -> map<Key, T, Compare, Allocator>; template<class InputIter, class Allocator> map(InputIter, InputIter, Allocator) -> map</*iter-key-type*/<InputIter>, /*iter-mapped-type*/<InputIter>, less</*iter-key-type*/<InputIter>>, Allocator>; template<ranges::input_range R, class Allocator> map(from_range_t, R&&, Allocator) -> map</*range-key-type*/<R>, /*range-mapped-type*/<R>, less</*range-key-type*/<R>>, Allocator>; template<class Key, class T, class Allocator> map(initializer_list<pair<Key, T>>, Allocator) -> map<Key, T, less<Key>, Allocator>; }
[编辑] 类模板 std::multimap
namespace std { template<class Key, class T, class Compare = less<Key>, class Allocator = allocator<pair<const Key, T>>> class multimap { public: // types using key_type = Key; using mapped_type = T; using value_type = pair<const Key, T>; using key_compare = Compare; using allocator_type = Allocator; using pointer = typename allocator_traits<Allocator>::pointer; using const_pointer = typename allocator_traits<Allocator>::const_pointer; using reference = value_type&; using const_reference = const value_type&; using size_type = /* implementation-defined */; using difference_type = /* implementation-defined */; using iterator = /* implementation-defined */; using const_iterator = /* implementation-defined */; using reverse_iterator = std::reverse_iterator<iterator>; using const_reverse_iterator = std::reverse_iterator<const_iterator>; using node_type = /* unspecified */; class value_compare { protected: Compare comp; value_compare(Compare c) : comp(c) { } public: bool operator()(const value_type& x, const value_type& y) const { return comp(x.first, y.first); } }; // construct/copy/destroy multimap() : multimap(Compare()) { } explicit multimap(const Compare& comp, const Allocator& = Allocator()); template<class InputIter> multimap(InputIter first, InputIter last, const Compare& comp = Compare(), const Allocator& = Allocator()); template<container-compatible-range<value_type> R> multimap(from_range_t, R&& rg, const Compare& comp = Compare(), const Allocator& = Allocator()); multimap(const multimap& x); multimap(multimap&& x); explicit multimap(const Allocator&); multimap(const multimap&, const type_identity_t<Allocator>&); multimap(multimap&&, const type_identity_t<Allocator>&); multimap(initializer_list<value_type>, const Compare& = Compare(), const Allocator& = Allocator()); template<class InputIter> multimap(InputIter first, InputIter last, const Allocator& a) : multimap(first, last, Compare(), a) { } template<container-compatible-range<value_type> R> multimap(from_range_t, R&& rg, const Allocator& a)) : multimap(from_range, std::forward<R>(rg), Compare(), a) { } multimap(initializer_list<value_type> il, const Allocator& a) : multimap(il, Compare(), a) { } ~multimap(); multimap& operator=(const multimap& x); multimap& operator=(multimap&& x) noexcept( allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_move_assignable_v<Compare>); multimap& operator=(initializer_list<value_type>); allocator_type get_allocator() const noexcept; // iterators iterator begin() noexcept; const_iterator begin() const noexcept; iterator end() noexcept; const_iterator end() const noexcept; reverse_iterator rbegin() noexcept; const_reverse_iterator rbegin() const noexcept; reverse_iterator rend() noexcept; const_reverse_iterator rend() const noexcept; const_iterator cbegin() const noexcept; const_iterator cend() const noexcept; const_reverse_iterator crbegin() const noexcept; const_reverse_iterator crend() const noexcept; // capacity bool empty() const noexcept; size_type size() const noexcept; size_type max_size() const noexcept; // modifiers template<class... Args> iterator emplace(Args&&... args); template<class... Args> iterator emplace_hint(const_iterator position, Args&&... args); iterator insert(const value_type& x); iterator insert(value_type&& x); template<class P> iterator insert(P&& x); iterator insert(const_iterator position, const value_type& x); iterator insert(const_iterator position, value_type&& x); template<class P> iterator insert(const_iterator position, P&& x); template<class InputIter> void insert(InputIter first, InputIter last); template<container-compatible-range<value_type> R> void insert_range(R&& rg); void insert(initializer_list<value_type>); node_type extract(const_iterator position); node_type extract(const key_type& x); template<class K> node_type extract(K&& x); iterator insert(node_type&& nh); iterator insert(const_iterator hint, node_type&& nh); iterator erase(iterator position); iterator erase(const_iterator position); size_type erase(const key_type& x); template<class K> size_type erase(K&& x); iterator erase(const_iterator first, const_iterator last); void swap(multimap&) noexcept(allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_swappable_v<Compare>); void clear() noexcept; template<class C2> void merge(multimap<Key, T, C2, Allocator>& source); template<class C2> void merge(multimap<Key, T, C2, Allocator>&& source); template<class C2> void merge(map<Key, T, C2, Allocator>& source); template<class C2> void merge(map<Key, T, C2, Allocator>&& source); // observers key_compare key_comp() const; value_compare value_comp() const; // map operations iterator find(const key_type& x); const_iterator find(const key_type& x) const; template<class K> iterator find(const K& x); template<class K> const_iterator find(const K& x) const; size_type count(const key_type& x) const; template<class K> size_type count(const K& x) const; bool contains(const key_type& x) const; template<class K> bool contains(const K& x) const; iterator lower_bound(const key_type& x); const_iterator lower_bound(const key_type& x) const; template<class K> iterator lower_bound(const K& x); template<class K> const_iterator lower_bound(const K& x) const; iterator upper_bound(const key_type& x); const_iterator upper_bound(const key_type& x) const; template<class K> iterator upper_bound(const K& x); template<class K> const_iterator upper_bound(const K& x) const; pair<iterator, iterator> equal_range(const key_type& x); pair<const_iterator, const_iterator> equal_range(const key_type& x) const; template<class K> pair<iterator, iterator> equal_range(const K& x); template<class K> pair<const_iterator, const_iterator> equal_range(const K& x) const; }; template<class InputIter, class Compare = less</*iter-key-type*/<InputIter>>, class Allocator = allocator</*iter-to-alloc-type*/<InputIter>>> multimap(InputIter, InputIter, Compare = Compare(), Allocator = Allocator()) -> multimap</*iter-key-type*/<InputIter>, /*iter-mapped-type*/<InputIter>, Compare, Allocator>; template<ranges::input_range R, class Compare = less</*range-key-type*/<R>>, class Allocator = allocator</*range-to-alloc-type*/<R>>> multimap(from_range_t, R&&, Compare = Compare(), Allocator = Allocator()) -> multimap</*range-key-type*/<R>, /*range-mapped-type*/<R>, Compare, Allocator>; template<class Key, class T, class Compare = less<Key>, class Allocator = allocator<pair<const Key, T>>> multimap(initializer_list<pair<Key, T>>, Compare = Compare(), Allocator = Allocator()) -> multimap<Key, T, Compare, Allocator>; template<class InputIter, class Allocator> multimap(InputIter, InputIter, Allocator) -> multimap</*iter-key-type*/<InputIter>, /*iter-mapped-type*/<InputIter>, less</*iter-key-type*/<InputIter>>, Allocator>; template<ranges::input_range R, class Allocator> multimap(from_range_t, R&&, Allocator) -> multimap</*range-key-type*/<R>, /*range-mapped-type*/<R>, less</*range-key-type*/<R>>, Allocator>; template<class Key, class T, class Allocator> multimap(initializer_list<pair<Key, T>>, Allocator) -> multimap<Key, T, less<Key>, Allocator>; }
[编辑] 缺陷报告
以下行为变更缺陷报告被追溯应用于先前发布的 C++ 标准。
DR | 应用于 | 已发布的行为 | 正确行为 |
---|---|---|---|
LWG 133 | C++98 | map::get_allocator 在概要中缺失 | 添加 |