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

class A {
public:
    unique_ptr<int[]> data;
    //int *data;

    A(int *d) : data(d) {
        //throw runtime_error("error");
    }
};

int main() {
    int *arr = new int[3]{1, 2, 3};

    A a(arr);
}