智能指针

一、shared_ptr

1. reset 用法

#include <iostream> #include <memory> class SharedptrTest { private: int index_; public: SharedptrTest(int index); ~SharedptrTest(); }; SharedptrTest::SharedptrTest(int index) : index_(index) { std::cout << "SharedptrTest(" << index_ << ")" << std::endl; } SharedptrTest::~SharedptrTest() { std::cout << "~SharedptrTest(" << index_ << ")" << std::endl; } int main(int argc, char const *argv[]) { std::shared_ptr<SharedptrTest> ptest; for (int i = 0; i < 3; i++) { std::cout << "-------" << i << "------" << std::endl; ptest.reset(new SharedptrTest(i)); } return 0; }

g++ --std=c++11 shartdptr.cpp

-------0------ SharedptrTest(0) -------1------ SharedptrTest(1) ~SharedptrTest(0) -------2------ SharedptrTest(2) ~SharedptrTest(1) ~SharedptrTest(2)