标准库头文件 <set>

此头文件是容器库的一部分。

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 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)	按照字典顺序比较 set 中的值 (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 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)	按照字典顺序比较 multiset 中的值 (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 set
  template<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)));
 
  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 multiset
  template<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)));
 
  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 InputIt>
      set(InputIt first, InputIt last,
          const Compare& comp = Compare(), const Allocator& = Allocator());
    set(const set& x);
    set(set&& x);
    explicit set(const Allocator&);
    set(const set&, const Allocator&);
    set(set&&, const Allocator&);
    set(initializer_list<value_type>, const Compare& = Compare(),
        const Allocator& = Allocator());
    template<class InputIt>
      set(InputIt first, InputIt last, const Allocator& a)
        : set(first, last, 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() const noexcept;
 
    // 迭代器
    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;
 
    // 容量
    [[nodiscard]] bool empty() const noexcept;
    size_type size() const noexcept;
    size_type max_size() const noexcept;
 
    // 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);
    iterator insert(const_iterator position, const value_type& x);
    iterator insert(const_iterator position, value_type&& x);
    template<class InputIt>
      void insert(InputIt first, InputIt last);
    void insert(initializer_list<value_type>);
 
    node_type extract(const_iterator position);
    node_type extract(const key_type& x);
    insert_return_type 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);
    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 InputIt,
           class Compare = less</*iter-value-type*/<InputIt>>,
           class Allocator = allocator</*iter-value-type*/<InputIt>>>
    set(InputIt, InputIt,
        Compare = Compare(), Allocator = Allocator())
      -> set</*iter-value-type*/<InputIt>, 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 InputIt, class Allocator>
    set(InputIt, InputIt, Allocator)
      -> set</*iter-value-type*/<InputIt>,
             less</*iter-value-type*/<InputIt>>, Allocator>;
 
  template<class Key, class Allocator>
    set(initializer_list<Key>, Allocator) -> set<Key, less<Key>, Allocator>;
 
  // 交换
  template<class Key, class Compare, class Allocator>
    void swap(set<Key, Compare, Allocator>& x,
              set<Key, Compare, Allocator>& y)
      noexcept(noexcept(x.swap(y)));
}

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 InputIt>
      multiset(InputIt first, InputIt last,
               const Compare& comp = Compare(), const Allocator& = Allocator());
    multiset(const multiset& x);
    multiset(multiset&& x);
    explicit multiset(const Allocator&);
    multiset(const multiset&, const Allocator&);
    multiset(multiset&&, const Allocator&);
    multiset(initializer_list<value_type>, const Compare& = Compare(),
             const Allocator& = Allocator());
    template<class InputIt>
      multiset(InputIt first, InputIt last, const Allocator& a)
        : multiset(first, last, 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() const noexcept;
 
    // 迭代器
    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;
 
    // 容量
    [[nodiscard]] bool empty() const noexcept;
    size_type size() const noexcept;
    size_type max_size() const noexcept;
 
    // 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 InputIt>
      void insert(InputIt first, InputIt last);
    void insert(initializer_list<value_type>);
 
    node_type extract(const_iterator position);
    node_type extract(const key_type& 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);
    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 InputIt,
           class Compare = less</*iter-value-type*/<InputIt>>,
           class Allocator = allocator</*iter-value-type*/<InputIt>>>
    multiset(InputIt, InputIt,
             Compare = Compare(), Allocator = Allocator())
      -> multiset</*iter-value-type*/<InputIt>, 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 InputIt, class Allocator>
    multiset(InputIt, InputIt, Allocator)
      -> multiset</*iter-value-type*/<InputIt>,
                  less<iter-value-type<InputIt>>, Allocator>;
 
  template<class Key, class Allocator>
    multiset(initializer_list<Key>, Allocator) -> multiset<Key, less<Key>, Allocator>;
 
  // 交换
  template<class Key, class Compare, class Allocator>
    void swap(multiset<Key, Compare, Allocator>& x,
              multiset<Key, Compare, Allocator>& y)
      noexcept(noexcept(x.swap(y)));
}

语言
标准库头文件
自立与有宿主实现
具名要求
语言支持库
概念库 (C++20)
诊断库
工具库
字符串库
容器库
迭代器库
范围库 (C++20)
算法库
数值库
本地化库
输入/输出库
文件系统库 (C++17)
正则表达式库 (C++11)
原子操作库 (C++11)
线程支持库 (C++11)
技术规范

标准库头文件 <set>

包含

类

函数

范围访问

概要

类模板 std::set

类模板 std::multiset