#include <iostream>
using namespace std;
class A {
public:
A() { cout << "A"; }
A(const A&) { cout << "a"; }
};
class B : public virtual A {
public:
B() { cout << "B"; }
B(const B&) { cout << "b"; }
};
class C : public virtual A {
public:
C() { cout << "C"; }
C(const C&) { cout << "c"; }
};
class D : public B, C {
public:
D() { cout << "D"; }
D(const D&) { cout << "d"; }
};
int main()
{
D d;
D d2{d}; // or: D d2 = d;
return 0;
}
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