*** auto_ptr指针应用（注意auto_ptr已经被弃用）

#include <iostream>
#include <memory>
#include <string.h>

using namespace std;

class Test
{
public:
    Test():name(NULL){}
    Test(const char * x)
    {
        if (x != NULL)
        {
            name = new char [strlen(x)+1];
            strcpy(name, x);
        }
    }
    ~Test()
    {
        if (name != NULL)
        {
            delete [] name;
            name = NULL;
        }
        cout << "Delete name" << endl;
    }
    Test & operator = (const char * str)
    {
        if (name != NULL)
        {
            delete [] name;
        }
        
        name = new char [strlen(str)+1];
        strcpy (name, str);
        
        return *this;
    }
    void ShowName (void)
    {
        cout << name << endl;
    }

public:
    char * name;
};

int main()
{
    auto_ptr<Test> TestPtr(new Test("Jason"));
    //Test * TestPtr = new Test("Jason");
    TestPtr->ShowName();
    *TestPtr = "Becky";
    TestPtr->ShowName();
    
    int y = 1;
    int x = 0;
    y = y / x;
    
    cout << "End of program!" << endl;
    
    return 0;
}

运行后屏幕输出为：说明出现异常后auto_ptr指向的对象的析构函数仍然被执行了。

Jason                                                                                                                                                                              
Becky                                                                                                                                                                              
End of program!                                                                                                                                                                    
Delete name

如果把上面代码中注释掉的代码打开，如下：

int main()
{
    //auto_ptr<Test> TestPtr(new Test("Jason"));
    Test * TestPtr = new Test("Jason");
    TestPtr->ShowName();
    *TestPtr = "Becky";
    TestPtr->ShowName();
    
    int y = 1;
    int x = 0;
    y = y / x;
    
    cout << "End of program!" << endl;
    
    return 0;
}

执行后屏幕显示如下：因为没有运用auto_ptr而用的裸指针，可以看到析构函数没有被调用

Jason                                                                                                                                                                              
Becky                                                                                                                                                                              
End of program!