c++智能指针练习

来源：互联网发布：沈阳思迅软件编辑：程序博客网时间：2024/06/05 17:22

实例如下：

#include <iostream>using namespace std;class counter{int m_use;    template <class T> friend class smartpointer;    counter(int use):m_use(use){}    counter(){ m_use = 0;}};template <class T>class smartpointer{public:smartpointer(T *ptr):m_pt(ptr),m_cnt(new counter(1)){cout<<"smartpointer::smartpointer() invoked " << m_cnt->m_use++ <<endl;}smartpointer(const smartpointer<T>& rhs){      m_pt = rhs.m_pt;m_cnt = rhs.m_cnt;    ++(m_cnt->m_use);cout<<"smartpointer::smartpointer(const smartpointer&) invoked " << m_cnt->m_use++ <<endl;}~smartpointer(){cout<<"SmartPointer::~SmartPointer() invoded" << m_cnt->m_use <<endl;if(--(m_cnt->m_use) == 0){delete m_pt;delete m_cnt;}}smartpointer& operator=(const smartpointer& rhs){if(rhs == *this)return *this;m_pt = rhs.m_pt;m_cnt = rhs.m_cnt;++(m_cnt->m_use);cout<<"SmartPointer::operator=SmartPointer() invoded" << m_cnt->m_use <<endl;return *this;}private:T *m_pt;counter *m_cnt;};class test{private:int t;int *value;public:test(int v):t(v), value(& v){cout << t <<endl;}~test(){delete value;cout << "test::~test() invoked" <<endl;}};int main(int argc, char *argv[]){test *t = new test(10);smartpointer<test> pp(t);smartpointer<test> pp2(pp);smartpointer<test> pp3 = pp2;    return 0;}

写的不太标准，主要参考c++ primer中的讲解

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