Enable_shared_from_this 知乎
WebJun 27, 2016 · The problem with the member function get_shared in the question is that it allows calls by both unique_ptr and shared_ptr with a difficult to distinguish between the two, thus unique_ptr is allowed to call this method and fails.. Moving the get_shared to be a static method which gets the pointer to share from, allows the distinguishing between … WebJul 8, 2024 · C++11 开始支持 enable_shared_from_this ,它是一个模板类,定义在头文件 ,其原型为:. template< class T > class enable_shared_from_this; …
Enable_shared_from_this 知乎
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Web解决这个问题很简单,只要 std::enable_shared_from_this 作为 Student 的基类: 正确代码: class Student : public std::enable_shared_from_this { public: Student( const string &name ) : name_( name ) { } void addToGroup( vector> &group ) { group.push_back( shared_from_this() ); } … WebMar 15, 2024 · enable_shared_from_this 类中定义了一个 weak_ptr, 起到了上文提到的从obj指针生成 shared_ptr 对象的作用. 按照先前的原理, 我们可能认为是在obj初始化的时候, 同时对 weak_this 进行初始化, 但是在这段代码里显然没有对 weak_this 进行任何初始化工作 (原始代码里也没有 ...
Web若一个类 T 继承 std::enable_shared_from_this ,则会为该类 T 提供成员函数: shared_from_this 。 当 T 类型对象 t 被一个为名为 pt 的 std::shared_ptr 类对象管理时,调用 T::shared_from_this 成员函数,将会返回一个新的 std::shared_ptr 对象,它与 pt 共享 t 的所有权。 成员函数 成员对象 注意 enable_shared_from_this 的常见实现为: … WebAug 2, 2024 · shared_ptr shared_from_this (); shared_ptr shared_from_this () const; Remarks When you derive objects from the enable_shared_from_this base class, the shared_from_this template member functions return a shared_ptr Class object that shares ownership of this instance with existing shared_ptr owners.
WebJan 29, 2024 · shared_from_this. enable_shared_from_this是一个类,将有上述需求的类继承自它,就可以解决上面所提出的问题。. enable_shared_from_this 有一个私有成员 … http://blog.guorongfei.com/2024/01/25/enbale-shared-from-this-implementaion/
WebNov 16, 2024 · 从 enable_shared_from_this 派生的对象可以在成员函数中使用 shared_from_this 方法来创建实例的 shared_ptr 所有者,这些所有者与现有 shared_ptr …
Webstd::enable_shared_from_this Returns a std::weak_ptr that tracks ownership of *this by all existing std::shared_ptr that refer to *this . Notes This is a copy of the private mutable weak_ptr member that is part of enable_shared_from_this. Return value std::weak_ptr that shares ownership of *this with pre-existing std::shared_ptr s Example firmware cho dvd androidWebenable_shared_from_this provides the safe alternative to an expression like std::shared_ptr(this), which is likely to result in this being destructed more than once by multiple owners that are unaware of each other (see … firmware cirkuit planetWebJul 26, 2024 · TL;DR. std::enable_shared_from_this必须要public继承,否则调用shared_from_this()不会编译失败,但运行时会抛std::bad_weak_ptr的异常。. 我看到项 … firmware cianet gw24acWebNov 17, 2024 · 1 Answer. Sorted by: 3. You appear to have a misunderstanding about shared_ptr and shared_from_this. You don't need to use shared_from_this in order to retrieve a shared_ptr if you already have one. In your example, you could just do: auto ptr_a = std::make_shared firmware chip macbook pro(); auto ptr_b = ptr_a; firmware cisco 6821WebMar 15, 2024 · enable_shared_from_this 类中定义了一个 weak_ptr, 起到了上文提到的从obj指针生成 shared_ptr 对象的作用. 按照先前的原理, 我们可能认为是在obj … firmware cho vinabox x2WebMar 18, 2024 · 1. The automatic linkage to enable_shared_from_this that gets set up when a shared_ptr is created only works if the class type T inherits exactly one unambiguous public enable_shared_from_this base. But B inherits two different enable_shared_from_this bases. Instead, you can have just the … firmware check point 1100