C++ RTTI

🔍 C++ RTTI – Know the Real Type at Runtime

RTTI stands for Run-Time Type Information. It helps you find out the actual type of an object while your program is running — like asking, “Hey, who are you really?” 🕵️‍♂️

RTTI is mainly useful when you’re dealing with inheritance and polymorphism.

✨ What RTTI Gives You

• typeid – tells you the type of an object
• dynamic_cast – safely casts pointers when using polymorphism

🔧 Example: Using typeid

#include <iostream>
#include <typeinfo>

using namespace std;

class Animal {
public:
    virtual void sound() {}
};

class Dog : public Animal {};

int main() {
    Dog d;
    Animal* a = &d;

    cout << "Type of a: " << typeid(*a).name() << endl;

    return 0;
}
  

🔧 Example: Using dynamic_cast

dynamic_cast lets you check if a base class pointer can be safely converted to a derived class pointer.

#include <iostream>

using namespace std;

class Animal {
public:
    virtual void sound() {}
};

class Cat : public Animal {
public:
    void meow() {
        cout << "Meow! 🐱" << endl;
    }
};

int main() {
    Animal* a = new Cat();

    Cat* c = dynamic_cast<Cat*>(a);
    if (c != nullptr) {
        c->meow();
    } else {
        cout << "Not a Cat!" << endl;
    }

    delete a;
    return 0;
}
  

🎯 Summary

• RTTI is useful for checking object types at runtime
• Use typeid to find the type name
• Use dynamic_cast for safe downcasting in polymorphism