How to call copy constructor of all base classes for copying most derived class object in diamond inheritance in C++?

Question

Consider the below code:

#include
using namespace std;
class A
{
public:
     A() {cout << \"1\";}
     A(const A &obj) {cout <<          


        

Answer 1

Alternative solution which doesn't require changing the inheritance modifiers of class B or C:

class A
{
public:
     A() {cout << "1";}
     A(const A &obj) {cout << "2";}
};

class B: virtual A
{
public:
    B() {cout << "3";}
    B(const B & obj) {cout<< "4";}
};

class C: virtual A
{
public:
   C() {cout << "5";}
   C(const C & obj) {cout << "6";}
};

class D:B,C,virtual A
{
public:
    D() {cout << "7";}
    D(const D & obj) : A(obj), B(obj), C(obj) {cout << "8";}
};