未完待续

 1 #include <iostream>
#include<typeinfo>
#include<vector>

using namespace std;

class Base{
public:
    virtual void fun(){cout << "Base::fun
";}
};
class Derived : public Base{
public:
    void fun(int i){cout << "Derived the i = " << i << endl;}
};
class Sunzi : public Derived{
public:
    void fun(){cout << "in Sunzi
";}
};

int main()
{
    Derived de;
    de.fun(1);
    //de.fun(); //error
    Sunzi sun;
    sun.fun();
    Base *ba = &sun;
    ba->fun();
    return 0;
}

#include <iostream>
#include<typeinfo>
#include<vector>

using namespace std;

class Base{
public:
    virtual void fun(){cout << "Base::fun
";}
};
class Derived : public Base{
public:
    void fun(){cout << "in Derived
";}
    void fun(int i){cout << "Derived the i = " << i << endl;}
};
class Sunzi : public Derived{
public:
    void fun(){cout << "in Sunzi
";}
    void fun(int i){cout << "Sunzi the i = " << i << endl;}
};

int main()
{
    Derived *de = new Derived();
    Derived de2;
    Base *ba;
    Sunzi sun;
//
    de->fun(1);
    de->fun(); //error

    ba = &de2;
    ba->fun();

    sun.fun();

    ba = &sun;
    ba->fun();

    de = &sun;
    de->fun();
    de->fun(1);
    return 0;
}

#include <iostream>
#include<typeinfo>
#include<vector>

using namespace std;

class Base{
public:
    virtual void fun(){cout << "Base::fun
";}
};
class Derived : public Base{
public:
    using Base::fun;    //using solve redefine
    void fun(int i){cout << "Derived the i = " << i << endl;}
};
class Sunzi : public Derived{
public:
    void fun(){cout << "in Sunzi
";}
};

int main()
{
    Derived de;
    de.fun(1);
    de.fun(); //ok
    Sunzi sun;
    sun.fun();
    Base *ba = &sun;
    ba->fun();
    return 0;
}

#include <iostream>
#include<typeinfo>
#include<vector>

using namespace std;

class Base{
public:
    virtual void fun(){cout << "Base::fun
";}
    virtual void fun(int i){cout << "Base:: i = " << i << endl;}
};
class Derived : public Base{
public:
    void fun(){cout << "in Derived
";}
    void fun(int i){cout << "Derived the i = " << i << endl;}
};

int main()
{
    Base *ba;
    Derived de;
    de.fun(1);
    de.fun(); //ok

    ba = &de;
    ba->fun();
    ba->fun(1);

    return 0;
}