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

class Foo {
public:
    Foo(int size)
        : size(size)
        , arr(new int[size]) {
        for ( int i = 0; i < size; i++ ){
            arr[i] = i;
        }
    }

    Foo(const Foo& foo)
        : size(foo.size) {

        foo.foo->print();

        arr = new int[size];
        unsafe { memcpy(arr, foo.arr, sizeof(int) * size); }
    }

    ~Foo(){
        unsafe { delete[] arr; }
    }

    void print(){
        for (int i = 0; i < size; i++) {
            unsafe { std::cout << arr[i] << " "; }
        }
        std::cout << "\n";
    }

    Foo& operator=(const Foo& foo) {
        this->~Foo();
        new(this)Foo(foo);
        return *this;
    }

    void set_other(const shared_ptr<Foo>& other) {
        foo = other;
    }
private:
    int size;
    int* arr;
    shared_ptr<Foo> foo;
};

int main() {
    shared_ptr<Foo> a = make_shared<Foo>(10);
    shared_ptr<Foo> b = make_shared<Foo>(20);

    b->set_other(a);

    a->print();
    b->print();

    *a = *b;

    return 0;
}