#include <iostream>
class A
{
public:
int age;
A() : age(10) { }
};
class B : /*virtual*/ public A
{
public:
B() { age = 20; }
};
class C : /*virtual*/ public A
{
public:
C() { age = 30; }
};
class D : public B, public C
{
};
int main()
{
D d;
C& c = d;
B& b = d;
std::cout << "B.age = " << b.age << std::endl; //B.age = 20
std::cout << "C.age = " << c.age << std::endl; //C.age = 30
}