#include <iostream>
using namespace std;
struct B
{
int i;
virtrual int f()
{
cout << "1";
return 1;
}
virtual const B &f() const
{
cout << "2";
return *this;
}
int g()
{
cout << "3";
return 3;
}
};
struct D: B
{
int i;
int f()
{
cout << "4";
return 4;
}
const B &f() const
{
cout << "5";
return *this;
}
int f(int = 0)
{
cout << "6";
return 6;
}
virtual int g()
{
cout << "7";
return 7;
}
};
int main()
{
D d;
const D d_const;
B b, *p = &d;
const B *p_const = &d_const;
b. f();
p->f();
p->g();
p_const->f();
d_const. f();
}
该程序的输出为：
