using namespace std;
#include <memory>
#include <iostream>
class B {};
class D : public B {};
class E : public B {};
class A {
public:
A & operator << ( std::unique_ptr<B> bp){
std::cout << " added a value " << std::endl;
return *this;
}
};
int main() {
// your code goes here
A a;
a << make_unique<D>() << make_unique<E>() ;
return 0;
}
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