标准库标头 <set>

 

C++

编译器支持

自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏(C++20)

语言支持库

概念库(C++20)

诊断库

内存管理库

元编程库(C++11)

通用工具库

容器库

迭代器库

范围库(C++20)

算法库

字符串库

文本处理库

数值库

日期和时间库

输入/输出库

文件系统库(C++17)

并发支持库(C++11)

执行控制库(C++26)

技术规范

符号索引

外部库

 

标准库头

语言支持 <cfloat> <climits> <compare>(C++20) <contracts>(C++26) <coroutine>(C++20) <csetjmp> <csignal> <cstdarg> <cstddef> <cstdint>(C++11) <cstdlib> <exception> <initializer_list>(C++11)    <limits> <new> <source_location>(C++20) <stdfloat>(C++23) <typeinfo> <version>(C++20) 概念 <concepts>(C++20) 诊断 <cassert> <cerrno> <debugging>(C++26) <stacktrace>(C++23) <stdexcept> <system_error>(C++11) 内存管理 <memory> <memory_resource>(C++17) <scoped_allocator>(C++11) 元编程 <type_traits>(C++11) <ratio>(C++11)

通用工具 <any>(C++17) <bitset> <bit>(C++20) <charconv>(C++17) <expected>(C++23) <format>(C++20) <functional> <optional>(C++17) <stdbit.h>(C++26) <tuple>(C++11) <typeindex>(C++11) <utility> <variant>(C++17) 容器 <array>(C++11) <deque> <flat_map>(C++23) <flat_set>(C++23) <forward_list>(C++11) <hive>(C++26) <inplace_vector>(C++26)    <list> <map> <mdspan>(C++23) <queue> <set> <span>(C++20) <stack> <unordered_map>(C++11) <unordered_set>(C++11) <vector> 迭代器 <iterator> 范围 <generator>(C++23) <ranges>(C++20)

算法 <algorithm> <numeric> 字符串 <cctype> <cstring> <cuchar>(C++11) <cwchar> <cwctype> <string_view>(C++17) <string> 文本处理 <clocale> <codecvt>(C++11/17/26*) <locale> <regex>(C++11) <text_encoding>(C++26)    cpp/header#数值库数值 <cfenv>(C++11) <cmath> <complex> <linalg>(C++26) <numbers>(C++20) <random>(C++11) <simd>(C++26) <stdckdint.h>(C++26) <valarray> 时间 <chrono>(C++11) <ctime> C 兼容性 <ccomplex>(C++11/17/20*) <ciso646>(C++20 前) <cstdalign>(C++11/17/20*) <cstdbool>(C++11/17/20*) <ctgmath>(C++11/17/20*)

输入/输出 <cinttypes>(C++11) <cstdio> <filesystem>(C++17) <fstream> <iomanip> <iosfwd> <iostream> <ios> <istream> <ostream> <print>(C++23) <spanstream>(C++23) <sstream> <streambuf> <strstream>(C++98/26*) <syncstream>(C++20) 并发支持 <atomic>(C++11) <barrier>(C++20) <condition_variable>(C++11) <future>(C++11) <hazard_pointer>(C++26) <latch>(C++20) <mutex>(C++11) <rcu>(C++26) <semaphore>(C++20) <shared_mutex>(C++14) <stdatomic.h>(C++23) <stop_token>(C++20) <thread>(C++11) 执行支持 <execution>(C++17)

 

此标头是容器库的一部分。

包含
<compare> (C++20)	三路比较运算符支持
<initializer_list> (C++11)	std::initializer_list 类模板
类
set	唯一键的集合，按照键排序 (类模板)
multiset	键的集合，按照键排序 (类模板)
函数
operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20 移除)(C++20 移除)(C++20 移除)(C++20 移除)(C++20 移除)(C++20)	按照字典顺序比较两个 set 的值 (函数模板)
std::swap(std::set)	特化 std::swap 算法 (函数模板)
erase_if(std::set) (C++20)	擦除所有满足特定判别标准的元素 (函数模板)
operator==operator!=operator<operator<=operator>operator>=operator<=> (C++20 移除)(C++20 移除)(C++20 移除)(C++20 移除)(C++20 移除)(C++20)	按照字典顺序比较两个 multiset 的值 (函数模板)
std::swap(std::multiset)	特化 std::swap 算法 (函数模板)
erase_if(std::multiset) (C++20)	擦除所有满足特定判别标准的元素 (函数模板)
范围访问
begincbegin (C++11)(C++14)	返回指向容器或数组起始的迭代器 (函数模板)
endcend (C++11)(C++14)	返回指向容器或数组结尾的迭代器 (函数模板)
rbegincrbegin (C++14)	返回指向一个容器或数组的逆向迭代器 (函数模板)
rendcrend (C++14)	返回容器或数组的逆向尾迭代器 (函数模板)
sizessize (C++17)(C++20)	返回容器或数组的大小 (函数模板)
empty (C++17)	检查容器是否为空 (函数模板)
data (C++17)	获得指向底层数组的指针 (函数模板)

概要

#include <compare>#include <initializer_list>   namespace std {// 类模板 settemplate<class Key, class Compare = less<Key>, class Allocator = allocator<Key>>class set;   template<class Key, class Compare, class Allocator>bool operator==(const set<Key, Compare, Allocator>& x, const set<Key, Compare, Allocator>& y);template<class Key, class Compare, class Allocator>/*synth-three-way-result*/<Key> operator<=>(const set<Key, Compare, Allocator>& x, const set<Key, Compare, Allocator>& y);   template<class Key, class Compare, class Allocator>void swap(set<Key, Compare, Allocator>& x, set<Key, Compare, Allocator>& y)noexcept(noexcept(x.swap(y)));   // set 的擦除template<class Key, class Compare, class Allocator, class Predicate>typename set<Key, Compare, Allocator>::size_type erase_if( set<Key, Compare, Allocator>& c, Predicate pred);   // 类模板 multisettemplate<class Key, class Compare = less<Key>, class Allocator = allocator<Key>>class multiset;   template<class Key, class Compare, class Allocator>bool operator==(const multiset<Key, Compare, Allocator>& x, const multiset<Key, Compare, Allocator>& y);template<class Key, class Compare, class Allocator>/*synth-three-way-result*/<Key> operator<=>(const multiset<Key, Compare, Allocator>& x, const multiset<Key, Compare, Allocator>& y);   template<class Key, class Compare, class Allocator>void swap(multiset<Key, Compare, Allocator>& x, multiset<Key, Compare, Allocator>& y)noexcept(noexcept(x.swap(y)));   // multiset 的擦除template<class Key, class Compare, class Allocator, class Predicate>typename multiset<Key, Compare, Allocator>::size_type erase_if( multiset<Key, Compare, Allocator>& c, Predicate pred);   namespace pmr {template<class Key, class Compare = less<Key>>using set =std::set<Key, Compare, polymorphic_allocator<Key>>;   template<class Key, class Compare = less<Key>>using multiset =std::multiset<Key, Compare, polymorphic_allocator<Key>>;}}

类模板 std::set

namespace std {template<class Key, class Compare = less<Key>, class Allocator = allocator<Key>>class set {public:// 类型using key_type = Key;using key_compare = Compare;using value_type = Key;using value_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 =/* 由实现定义 */;using difference_type =/* 由实现定义 */;using iterator =/* 由实现定义 */;using const_iterator =/* 由实现定义 */;using reverse_iterator =std::reverse_iterator<iterator>;using const_reverse_iterator =std::reverse_iterator<const_iterator>;using node_type =/* 未指明 */;using insert_return_type =/*insert-return-type*/<iterator, node_type>;   // 构造/复制/销毁 set(): set(Compare()){}explicit set(const Compare& comp, const Allocator&= Allocator());template<class InputIter> set(InputIter first, InputIter last, const Compare& comp = Compare(), const Allocator&= Allocator());template<container-compatible-range<value_type> R> set(from_range_t, R&& rg, const Compare& comp = Compare(), const Allocator&= Allocator()); set(const set& x); set(set&& x);explicit set(const Allocator&); set(const set&, const type_identity_t<Allocator>&); set(set&&, const type_identity_t<Allocator>&); set(initializer_list<value_type>, const Compare&= Compare(), const Allocator&= Allocator());template<class InputIter> set(InputIter first, InputIter last, const Allocator& a): set(first, last, Compare(), a){}template<container-compatible-range<value_type> R> set(from_range_t, R&& rg, const Allocator& a)): set(from_range, std::forward<R>(rg), Compare(), a){} set(initializer_list<value_type> il, const Allocator& a): set(il, Compare(), a){} ~set(); set& operator=(const set& x); set& operator=(set&& x)noexcept(allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_move_assignable_v<Compare>); set& operator=(initializer_list<value_type>); allocator_type get_allocator()constnoexcept;   // 迭代器 iterator begin()noexcept; const_iterator begin()constnoexcept; iterator end()noexcept; const_iterator end()constnoexcept;   reverse_iterator rbegin()noexcept; const_reverse_iterator rbegin()constnoexcept; reverse_iterator rend()noexcept; const_reverse_iterator rend()constnoexcept;   const_iterator cbegin()constnoexcept; const_iterator cend()constnoexcept; const_reverse_iterator crbegin()constnoexcept; const_reverse_iterator crend()constnoexcept;   // 容量bool empty()constnoexcept; size_type size()constnoexcept; size_type max_size()constnoexcept;   // 修改器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 K> pair<iterator, bool> insert(K&& x); iterator insert(const_iterator position, const value_type& x); iterator insert(const_iterator position, value_type&& x);template<class K> iterator insert(const_iterator position, K&& 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); insert_return_type insert(node_type&& nh); iterator insert(const_iterator hint, node_type&& nh);   iterator erase(iterator position) requires(!same_as<iterator, const_iterator>); 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(set&)noexcept(allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_swappable_v<Compare>);void clear()noexcept;   template<class C2>void merge(set<Key, C2, Allocator>& source);template<class C2>void merge(set<Key, C2, Allocator>&& source);template<class C2>void merge(multiset<Key, C2, Allocator>& source);template<class C2>void merge(multiset<Key, C2, Allocator>&& source);   // 观察器 key_compare key_comp()const; value_compare value_comp()const;   // set 操作 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-value-type*/<InputIter>>, class Allocator = allocator</*iter-value-type*/<InputIter>>> set(InputIter, InputIter, Compare = Compare(), Allocator = Allocator())-> set</*iter-value-type*/<InputIter>, Compare, Allocator>;   template<ranges::input_range R, class Compare = less<ranges::range_value_t<R>>, class Allocator = allocator<ranges::range_value_t<R>>> set(from_range_t, R&&, Compare = Compare(), Allocator = Allocator())-> set<ranges::range_value_t<R>, Compare, Allocator>;   template<class Key, class Compare = less<Key>, class Allocator = allocator<Key>> set(initializer_list<Key>, Compare = Compare(), Allocator = Allocator())-> set<Key, Compare, Allocator>;   template<class InputIter, class Allocator> set(InputIter, InputIter, Allocator)-> set</*iter-value-type*/<InputIter>, less</*iter-value-type*/<InputIter>>, Allocator>;   template<ranges::input_range R, class Allocator> set(from_range_t, R&&, Allocator)-> set<ranges::range_value_t<R>, less<ranges::range_value_t<R>>, Allocator>;   template<class Key, class Allocator> set(initializer_list<Key>, Allocator)-> set<Key, less<Key>, Allocator>;}

类模板 std::multiset

namespace std {template<class Key, class Compare = less<Key>, class Allocator = allocator<Key>>class multiset {public:// 类型using key_type = Key;using key_compare = Compare;using value_type = Key;using value_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 =/* 由实现定义 */;using difference_type =/* 由实现定义 */;using iterator =/* 由实现定义 */;using const_iterator =/* 由实现定义 */;using reverse_iterator =std::reverse_iterator<iterator>;using const_reverse_iterator =std::reverse_iterator<const_iterator>;using node_type =/* 未指明 */;   // 构造/复制/销毁 multiset(): multiset(Compare()){}explicit multiset(const Compare& comp, const Allocator&= Allocator());template<class InputIter> multiset(InputIter first, InputIter last, const Compare& comp = Compare(), const Allocator&= Allocator());template<container-compatible-range<value_type> R> multiset(from_range_t, R&& rg, const Compare& comp = Compare(), const Allocator&= Allocator()); multiset(const multiset& x); multiset(multiset&& x);explicit multiset(const Allocator&); multiset(const multiset&, const type_identity_t<Allocator>&); multiset(multiset&&, const type_identity_t<Allocator>&); multiset(initializer_list<value_type>, const Compare&= Compare(), const Allocator&= Allocator());template<class InputIter> multiset(InputIter first, InputIter last, const Allocator& a): multiset(first, last, Compare(), a){}template<container-compatible-range<value_type> R> multiset(from_range_t, R&& rg, const Allocator& a)): multiset(from_range, std::forward<R>(rg), Compare(), a){} multiset(initializer_list<value_type> il, const Allocator& a): multiset(il, Compare(), a){} ~multiset(); multiset& operator=(const multiset& x); multiset& operator=(multiset&& x)noexcept( allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_move_assignable_v<Compare>); multiset& operator=(initializer_list<value_type>); allocator_type get_allocator()constnoexcept;   // 迭代器 iterator begin()noexcept; const_iterator begin()constnoexcept; iterator end()noexcept; const_iterator end()constnoexcept;   reverse_iterator rbegin()noexcept; const_reverse_iterator rbegin()constnoexcept; reverse_iterator rend()noexcept; const_reverse_iterator rend()constnoexcept;   const_iterator cbegin()constnoexcept; const_iterator cend()constnoexcept; const_reverse_iterator crbegin()constnoexcept; const_reverse_iterator crend()constnoexcept;   // 容量bool empty()constnoexcept; size_type size()constnoexcept; size_type max_size()constnoexcept;   // 修改器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); iterator insert(const_iterator position, const value_type& x); iterator insert(const_iterator position, value_type&& 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) requires(!same_as<iterator, const_iterator>); 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(multiset&)noexcept(allocator_traits<Allocator>::is_always_equal::value&& is_nothrow_swappable_v<Compare>);void clear()noexcept;   template<class C2>void merge(multiset<Key, C2, Allocator>& source);template<class C2>void merge(multiset<Key, C2, Allocator>&& source);template<class C2>void merge(set<Key, C2, Allocator>& source);template<class C2>void merge(set<Key, C2, Allocator>&& source);   // 观察器 key_compare key_comp()const; value_compare value_comp()const;   // set 操作 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-value-type*/<InputIter>>, class Allocator = allocator</*iter-value-type*/<InputIter>>> multiset(InputIter, InputIter, Compare = Compare(), Allocator = Allocator())-> multiset</*iter-value-type*/<InputIter>, Compare, Allocator>;   template<ranges::input_range R, class Compare = less<ranges::range_value_t<R>>, class Allocator = allocator<ranges::range_value_t<R>>> multiset(from_range_t, R&&, Compare = Compare(), Allocator = Allocator())-> multiset<ranges::range_value_t<R>, Compare, Allocator>;   template<class Key, class Compare = less<Key>, class Allocator = allocator<Key>> multiset(initializer_list<Key>, Compare = Compare(), Allocator = Allocator())-> multiset<Key, Compare, Allocator>;   template<class InputIter, class Allocator> multiset(InputIter, InputIter, Allocator)-> multiset</*iter-value-type*/<InputIter>, less</*iter-value-type*/<InputIter>>, Allocator>;   template<ranges::input_range R, class Allocator> multiset(from_range_t, R&&, Allocator)-> multiset<ranges::range_value_t<R>, less<ranges::range_value_t<R>>, Allocator>;   template<class Key, class Allocator> multiset(initializer_list<Key>, Allocator)-> multiset<Key, less<Key>, Allocator>;}

缺陷报告

下列更改行为的缺陷报告追溯地应用于以前出版的 C++ 标准。

缺陷报告	应用于	出版时的行为	正确行为
LWG 214	C++98	概要中 std::set 和 std::multiset 的成员 find，lower_bound， upper_bound 和 equal_range 的声明与关联容器的要求不匹配	已改正