std::owner_less

 

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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
template<> struct owner_less<void>;		(C++17 起)

std::owner_less<void> 是拥有待推导形参类型的 std::owner_less 特化。

嵌套类型

嵌套类型	定义
is_transparent	未指定

成员函数

operator()

用基于所有者的语义比较其实参 (函数)

std::owner_less<void>::operator()

template< class T, class U > bool operator()( const std::shared_ptr<T>& lhs,                  const std::shared_ptr<U>& rhs ) const noexcept;		(C++17 起)
template< class T, class U > bool operator()( const std::shared_ptr<T>& lhs,                  const std::weak_ptr<U>& rhs ) const noexcept;		(C++17 起)
template< class T, class U > bool operator()( const std::weak_ptr<T>& lhs,                  const std::shared_ptr<U>& rhs ) const noexcept;		(C++17 起)
template< class T, class U > bool operator()( const std::weak_ptr<T>& lhs,                  const std::weak_ptr<U>& rhs ) const noexcept;		(C++17 起)

用基于所有者的语义比较 lhs 与 rhs。相当于调用 lhs.owner_before(rhs)。

顺序是严格弱序关系。

仅当 lhs 与 rhs 都为空或共享所有权时才等价。

参数

lhs, rhs

-

要比较的共享所有权指针

返回值

在基于所有者的顺序确定 lhs 小于 rhs 时返回 true。

注解

功能特性测试宏	值	标准	功能特性
__cpp_lib_transparent_operators	201510L	(C++17)	透明的 std::owner_less（std::owner_less<void>）

参阅

owner_before	提供基于持有者的共享指针排序 (std::shared_ptr<T> 的公开成员函数)
owner_before	提供弱指针的基于拥有者的排序 (std::weak_ptr<T> 的公开成员函数)