#include <iostream> #include <memory> using namespace std; struct Task { int mId; Task(int id) :mId(id) { cout << "Task::Constructor" << endl; } ~Task() { cout << "Task::Destructor" << endl; } }; int main() { //
In the first case, you manually created a newSobject, and then passed a pointer to it to theshared_ptrconstructor. Theshared_ptradopts the raw pointer and creates a control block to monitor its lifetime. When the last shared pointer destructs, theDispose()method deletes the pointer you pass...
owner_before() 理解了aliasing constructor之后,shared_pointer::owner_before()就更好理解了;(参考https://www.zhihu.com/question/24816143) 在标准库的shared_ptr中,operator<,比较的是stored pointer,因此上面举例的那种情况,p9和obj两个shared_ptr是不相等的;而owner_before()是基于owner pointer的比较,因此p9...
constructorwithno managed object1// shared_ptr 默认构造函数分配的是空指针constructorwithobject Foo...2// sh2 和sh3指向的都是同一个内存,所以他们的引用计数都是22~Foo...constructorwithobject and deleter Foo...Foo...Calldeletefrom lambda...~Foo...Calldeletefromfunctionobject...~Foo.. 2.reset...
Theshared_ptrconstructor detects the presence of a uniquestd::enable_shared_from_thisbase class by using theesft_detectorthat I put in the expository declaration. template<typename T, typename = void> struct supports_esft : std::false_type {}; ...
std::shared_ptr alias constructor structX {inta; }; shared_ptr<X> px(newX); shared_ptr<int> pi(px, &px->a); shared_ptr<X> sp1(newX); shared_ptr<X> sp2(sp1,newX);//ERROR: delete for this X will never be calledsp1.reset();//deletes first X; makes sp1 emptyshared_ptr<...
MyClass() { cout "MyClass constructor" endl; } ~MyClass() { cout "MyClass destructor" endl; } };int main() { std::shared\_ptr<MyClass> p1 = std::make\_shared<MyClass>();std::shared\_ptr<MyClass> p2 = p1;p2->something();p2.reset();return 0;} ```在这个示例中，p1和p2...
让你好好体会一下，“The object does not own p ”意思：// shared_ptr constructor example#include...
std::shared_ptrmay be used with an incomplete typeT. However, the constructor from a raw pointer (template shared_ptr(Y)) and the templatevoid reset(Y) member function may only be called with a pointer to a complete type (note that std::unique_ptr may be constructed from a raw pointer...
classMyClass{public:MyClass(){std::cout<<"MyClass default constructor"<<std::endl;}~MyClass(){std::cout<<"MyClass destructor"<<std::endl;}voiddoSomething(){std::cout<<"Doing something in MyClass"<<std::endl;}};intmain(){std::shared_ptrptr1(newMyClass());// 创建一个shared_ptr...