C ++：将自动分配的对象添加到std :: vector

#include <iostream>
#include <vector>
using namespace std;

class AClass
{
    public:
        int data;

        AClass() 
        { data = -333; cout << \"+ Creating default \" << data << endl; }

        AClass(const AClass &copy) 
        { data = copy.data; cout << \"+ Creating copy of \" << data << endl; }

        AClass(int d) 
        { data = d; cout << \"+ Creating \" << data << endl; }

        ~AClass() 
        { cout << \"- Deleting \" << data << endl; }

        AClass& operator = (const AClass &a)
        {  data = a.data; cout << \"= Calling operator=\" << endl; }
};

int main(void)
{
    vector<AClass> v;

    for (int i = 3; i--; )
        v.push_back(AClass(i));

    vector<AClass>::iterator it = v.begin();
    while (it != v.end())
        cout << it->data << endl, it++;

    return 0;
}

+ Creating 2
+ Creating copy of 2
- Deleting 2
+ Creating 1
+ Creating copy of 1
+ Creating copy of 2
- Deleting 2
- Deleting 1
+ Creating 0
+ Creating copy of 0
+ Creating copy of 2
+ Creating copy of 1
- Deleting 2
- Deleting 1
- Deleting 0
2
1
0
- Deleting 2
- Deleting 1
- Deleting 0

class AClass
{
    public:
        int data;

        AClass(int d) 
        { data = d; cout << \"+ Creating \" << data << endl; }

        ~AClass() 
        { cout << \"- Deleting \" << data << endl; }
};

+ Creating 2
- Deleting 2
+ Creating 1
- Deleting 2
- Deleting 1
+ Creating 0
- Deleting 2
- Deleting 1
- Deleting 0
2
1
0
- Deleting 2
- Deleting 1
- Deleting 0