std::owner_hash

 

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智能指针 unique_ptr (C++11) shared_ptr (C++11) weak_ptr (C++11) auto_ptr (C++17 前*) owner_less (C++11) owner_less<void> (C++17) owner_hash (C++26) owner_equal (C++26) enable_shared_from_this (C++11) bad_weak_ptr (C++11) default_delete (C++11) out_ptr_t (C++23) inout_ptr_t (C++23) 低层内存管理 operator new operator new[] operator delete operator delete[] get_new_handler (C++11) set_new_handler launder (C++17) bad_alloc bad_array_new_length (C++11) nothrow_t align_val_t (C++17) destroying_delete_t (C++20) new_handler nothrow 杂项 pointer_traits (C++11) to_address (C++20) addressof (C++11) align (C++11) assume_aligned (C++20) C 库 malloc calloc realloc    aligned_alloc (C++17) free

 

在标头 <memory> 定义
struct owner_hash;		(C++26 起)

此函数对象为 std::weak_ptr 和 std::shared_ptr 提供基于所有者（而非基于值）的散列计算。

嵌套类型

嵌套类型	定义
is_transparent	未指明

成员函数

operator()

计算共享所有权指针的散列 (函数)

std::owner_less::operator()

template< class T > std::size_t operator()( const std::shared_ptr<T>& key ) const noexcept;	(1)	(C++26 起)
template< class T > std::size_t operator()( const std::weak_ptr<T>& key ) const noexcept;	(2)	(C++26 起)

等价于 return key.owner_hash();。

参数

key

-

要散列的共享所有权指针

返回值

对于共享相同所有权的任何 std::shared_ptr 或 std::weak_ptr 对象都相同的散列值。

注解

功能特性测试宏	值	标准	功能特性
__cpp_lib_smart_ptr_owner_equality	202306L	(C++26)	使 std::shared_ptr 和 std::weak_ptr 可用作无序关联容器中的键

参阅

owner_hash (C++26)	提供基于所有者的共享指针散列 (std::shared_ptr<T> 的公开成员函数)
owner_hash (C++26)	提供弱指针的基于所有者的散列 (std::weak_ptr<T> 的公开成员函数)