如何确定在使用指针数组时指向哪个派生类

#include<iostream>
using namespace std;

class Base {
public:
    virtual void display() {
        cout << "Base class display function"<< endl;
    }
};

class Derived1 : public Base {
public:
    void display() override {
        cout << "Derived1 class display function"<< endl;
    }
};

class Derived2 : public Base {
public:
    void display() override {
        cout << "Derived2 class display function"<< endl;
    }
};

int main() {
    Base* base_ptr[2];
    Derived1 d1;
    Derived2 d2;

    base_ptr[0] = &d1;
    base_ptr[1] = &d2;

    for (int i = 0; i < 2; i++) {
        base_ptr[i]->display();
    }

    return 0;
}

Derived1 class display function
Derived2 class display function