Итератор вектора

#include <iostream>
#include <vector>
 
using namespace std;
 
 
 
class Alfa {
    public:
        static int count;
        Alfa();
        ~Alfa();
        friend ostream &operator << (ostream &stream, Alfa *obj);
};
 
ostream &operator << (ostream &stream, Alfa obj) {
    stream << obj.count << " - item number." << endl;
}
 
int Alfa::count = 0;
 
Alfa::Alfa() {
    if(count == 0) cout << "First object has been created." << endl;
}
 
Alfa::~Alfa() {
    if(count == 0) cout << "Last object has been destroyed." << endl;
}
 
 
int main() {
    
    vector<Alfa> v;
    
    for (int i = 0; i < 10; i++) v.push_back(Alfa());
    
    for (int i = 0; i < v.size(); i++) cout << v[i];
    
    vector<int>:: iterator p = v.begin();
    v.erase(p, p + 10);
}