CODEWITHSUNDEEP
c++debugging
Sydney.Ka
Sydney.Ka

Reputation: 175

What happens when a reference of an object (with different types) is deleted?

I'm kind of confused about how the reference works in the code below. From what I understand, b is just an alias of d1. So what's the difference between delete &b and delete d1 ?

b is of type Base but still is an alias of type f, so what differentiates them?

#include <iostream>

using namespace std;

class Base
{
public:
    Base(){
        cout << "Base Constructor Called\n";
    }
    ~Base(){
        cout << "Base Destructor called\n";
    }
};

class Derived1: public Base
{
public:
    Derived1(){
        cout << "Derived constructor called\n";
    }
    ~Derived1(){
        cout << "Derived destructor called\n";
    }
};

int main()
{
    Derived1 *d1 = new Derived1();
    Base &b = *d1;
    delete &b;
}

Upvotes: 0

Views: 64

Answers (1)

Lightness Races in Orbit
Lightness Races in Orbit

Reputation: 385385

They are differentiated by type.

  • b refers to an object of type Base.

  • d1 points to an object of type Derived1.

Those are related, but distinct types.

Your object is a Derived1, not just a Base. This matters to delete. Make your destructors virtual and you'll get away with it, because that's how polymorphism works. Otherwise, you have undefined behaviour and there is no meaning to your program.

Upvotes: 2

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