智能指针

首先编写SmartPointer.h

#ifndef SMARTPOINTER_H
#define SMARTPOINTER_H

namespace MyLib {

template<typename T>
class SmartPointer
{

protected:
    T* m_pointer;
public:
    SmartPointer(T* p=NULL){
        m_pointer = p;
    }
    //指针生命周期结束，主动释放空间
    ~SmartPointer(){
        delete m_pointer;
    }
    //直接赋值
    SmartPointer(const SmartPointer<T>& obj){
        m_pointer =obj.m_pointer;
        //同一片堆空间只能由一个指针使用
        const_cast<SmartPointer<T>&>(obj).m_pointer = NULL;
    }
    //=赋值
    SmartPointer<T>& operator=(const SmartPointer<T>& obj){
        if(this != &obj){
            delete m_pointer;
            m_pointer =obj.m_pointer;
            //同一片堆空间只能由一个指针使用
            const_cast<SmartPointer<T>&>(obj).m_pointer = NULL;
        }
        return *this;
    }

    T* operator->(){
        return m_pointer;
    }
    T& operator *(){
        return *m_pointer;
    }

    bool isNull(){
        return m_pointer == NULL;
    }

    T* get(){
        return m_pointer;
    }


};




}

#endif // SMARTPOINTER_H

2.  测试代码：

#include <iostream>
#include <smartpointer.h>

using namespace std;
using namespace MyLib;

class Test
{
public:
    Test() {
        cout<<"Test()"<<endl;
    }
    ~Test(){
        cout<<"~Test()"<<endl;
    }
};
int main()
{

    SmartPointer<Test> sp = new Test();

    return 0;
}

 

运行，实现简单的智能指针功能