convert 'std::vector<>::iterator {aka __gnu_cxx::__normal_iterator<*, std::vector<> >}' to '*' in in

错误程序：

#include <iostream>
#include <vector>

using namespace std;

struct A
{
    int x;
    A(int y) {x = y;}
};

int main()
{
    A a(11217);
    vector<A> V;
    V.push_back(a);
    vector<A>::iterator it = V.begin();
    A *p = it;
    return 0;
}#include <iostream>
#include <vector