What is the difference between shared_ptr and weak_ptr in C++?

What is the difference between shared_ptr and weak_ptr in C++?

In C++, shared_ptr is a smart pointer that retains shared ownership of an object, while weak_ptr is used to break circular references by providing a non-owning reference to the object.

Can you explain how circular references can be a problem?

Circular references occur when two or more objects reference each other, preventing their memory from being freed. This can lead to memory leaks.

How do I use weak_ptr to avoid memory leaks?

You can use weak_ptr to hold a reference to an object managed by shared_ptr. When you need to access the object, you can convert it to shared_ptr using lock(), which returns a valid pointer if the object still exists.

Are there any performance implications when using weak_ptr?

Yes, weak_ptr has a slight overhead due to the need to manage the reference count, but it is generally negligible compared to the benefits of preventing memory leaks.