std::weak_ptr 的推導指引

 

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std::weak_ptr

成員函式

weak_ptr::weak_ptr

weak_ptr::~weak_ptr

weak_ptr::operator=

修改器

weak_ptr::reset

weak_ptr::swap

觀察器

weak_ptr::use_count

weak_ptr::expired

weak_ptr::lock

weak_ptr::owner_before

weak_ptr::owner_hash (C++26)

weak_ptr::owner_equal (C++26)

非成員函式

swap(std::weak_ptr)

輔助類

atomic<std::weak_ptr> (C++20)

推導指南(C++17)

 

定義於標頭檔案 <memory>
template< class T > weak_ptr( std::shared_ptr<T> ) -> weak_ptr<T>;		(C++17 起)

為 std::weak_ptr 提供了一個推導指引，以處理隱式推導指引遺漏的邊緣情況。

示例

執行此程式碼

#include <memory>
 
int main()
{
    auto p = std::make_shared<int>(42);
    std::weak_ptr w{p}; // explicit deduction guide is used in this case
}