#include <iostream>
using namespace std;

class Derived {
public:
    Derived() {
        cout << "Derived constructor" << endl;
    }

    ~Derived() {
        cout << "Derived destructor" << endl;
    }
};

class Base {
private:
    int *a;
public:
    Base() {
        Derived b;

        a = new int[100];

        throw runtime_error("error");
    }

    ~Base() {
        // delete[] a;
    }
};

int main() {
    Base base;

    return 0;
}

// Вывод:
Derived constructor
terminate called after throwing an instance of 'std::runtime_error'
  what():  error