2021-08-26(代码片段)

#include <iostream>
#include <string>

using namespace std;

class Test

    int i;
public:
    Test(int i)
    
        this->i = i;
    
    int value()
    
        return i;
    
    ~Test()
    
    
;

int main()

    for(int i=0; i<5; i++)
    
        Test* p = new Test(i);
        
        cout << p->value() << endl;
        
    
    
    
    return 0;

以上代码没有释放内存，会导致内存泄漏

#include <iostream>
#include <string>

using namespace std;

class Test

    int i;
public:
    Test(int i)
    
        cout << "Test(int i)" << endl;
        this->i = i;
    
    int value()
    
        return i;
    
    ~Test()
    
        cout << "~Test()" << endl;
    
;

class Pointer

    Test* mp;
public:
	//智能指针很妙，关键在于构造函数，将Pointer类中的指针
	//指向其他类中的指针所指向的空间
    Pointer(Test* p = NULL)
    
        mp = p;
    
    Pointer(const Pointer& obj)
    
        mp = obj.mp;
        const_cast<Pointer&>(obj).mp = NULL;//剥夺对象只读属性
    
    Pointer& operator = (const Pointer& obj)
    
        if( this != &obj )
        
            delete mp;
            mp = obj.mp;
            const_cast<Pointer&>(obj).mp = NULL;//剥夺对象只读属性
        
        
        return *this;
    
    Test* operator -> ()
    
        return mp;
    
    Test& operator * ()
    
        return *mp;
    
    bool isNull()
    
        return (mp == NULL);
    
    ~Pointer()
    
        delete mp;
    
;

int main()

    Pointer p1 = new Test(0);
    
    cout << p1->value() << endl;
    
    Pointer p2 = p1;
    
    cout << p1.isNull() << endl;
    
    cout << p2->value() << endl;
    
    return 0;

将Pointer指针对象进行比较会报错（对象之间不能比较）

智能指针只能指向堆空间，不能指向栈空间

小结