how with iterator in c++ std::set we can access member function

 #include <iostream>
    #include <set>
    using namespace std;
    class A;

    std::set<A> m_vector;
    std::set<A>::iterator iter = m_vector.begin();

    class  A
   {
     public:
        int age;
        A()
        {
            cout << "enter age" << endl;
            cin >> age;
        }

        int getAge() 
        {
           return age;
        }
     private:

    };
    void addNewVoter()
    {
        m_vector.insert(A());
    }
    int main()
    {
         addNewVoter();
         addNewVoter();`
         addNewVoter();`
        for (size_t i = 0; i < m_vector.size(); i++)
        {`cout << (*iter)->getAge(); /* here is the mistake i can't invoke this*/  
            iter++;`

        }

   }

My question is how i can invoke member function with iterator ??