#include <iostream>
using namespace std;

class A {
public:
    int* data;
    A(int* d) : data(d) {
        throw runtime_error("err");
    }
};

class B {
public:
    int* data2;
    A* a;
    B(A* aaa) : data2(new int[10]), a(aaa) {
        delete[] data2;
    }
};

int main() {
    A* c;
    B base(c);
}