#include <vector>
#include <memory>
#include <iostream>
using namespace std;

class Foo{
public:
    Foo(int k)
        : k1(k)
        , k2(k){
    }

    Foo(const Foo& foo)
        : k1(foo.k1){
        std::cout << foo.foo->k1 << " " << foo.foo->k2 << "\n";
        k2 = foo.k2;
    }

    void set_other(const shared_ptr<Foo>& other){
        foo = other;
    }
private:
    int k1, k2;
    shared_ptr<Foo> foo;
};

int main(){
    shared_ptr<Foo> a = make_shared<Foo>(1);
    shared_ptr<Foo> b = make_shared<Foo>(2);

    b->set_other(a);

    *a = *b;

    return 0;
}