(data, other.data); std::cout << "Copy Constructor: " << data << std::endl; } // 赋值运算符,实现深拷贝 MyClass& operator=(const MyClass& other) { if (this == &other) { return *this; } delete[] data; data = new char[strlen(other.data)...
cout << p1.get() << endl; // copy constructor called, this makes p1 empty. auto_ptr <A> p2(p1); p2 -> show(); // p1 is empty now cout << p1.get() << endl; // p1 gets copied in p2 cout<< p2.get() << endl; return 0; } Output: A::show() 0x1b42c20 A::sh...
一: All member functions (including copy constructor and copy assignment) can be called by multiple threads on different instances of shared_ptr withou
If the lambda or function doesn't store the pointer, then pass the shared_ptr by reference to avoid invoking the copy constructor for each element. C++ Afrita void use_shared_ptr_by_value(shared_ptr<int> sp); void use_shared_ptr_by_reference(shared_ptr<int>& sp); void use_shared_...
copy构造函数的话,引用计数都会增加{std::cout<<"constructor with object\n";std::shared_ptr<Foo>sh2(newFoo);std::shared_ptr<Foo>sh3(sh2);std::cout<<sh2.use_count()<<'\n';std::cout<<sh3.use_count()<<'\n';}// 可以指定删除的函数,并传递给构造函数{std::cout<<"constructor ...
4.重载copy constructor,使其引用次数加一。 5.重载operator=,如果原来的shared_ptr已经有对象,则让其引用次数减一并判断引用是否为零(是否调用delete)。 然后将新的对象引用次数加一。 6.重载析构函数,使引用次数减一并判断引用是否为零(是否调用delete)。
std::shared_ptr<int> b(a, p); // alias constructor std::cout << "comparing a and b...\n" << std::boolalpha; std::cout << "value-based: " << (!(a < b) && !(b < a)) << '\n'; std::cout << "owner-based: " << (!a.owner_before(b) && !b.owner_before(a)...
Copy This prints: Resource acquired Killing one shared pointer Killing another shared pointer Resource destroyed In the above code, we create a dynamic Resource object, and set a std::shared_ptr named ptr1 to manage it. Inside the nested block, we use the copy constructor to create a secon...
4.重载copy constructor,使其引用次数加一。 5.重载operator=,如果原来的shared_ptr已经有对象,则让其引用次数减一并判断引用是否为零(是否调用delete)。 然后将新的对象引用次数加一。 6.重载析构函数,使引用次数减一并判断引用是否为零(是否调用delete)。
P ptr; // copy constructor must not throw D del; // copy constructor must not throw public: sp_counted_base_impl(P p, D d): ptr(p), del(d) { } }; sp_counted_base的构造函数应该先被调用: class sp_counted_base { public: ...