What are the differences between unique_ptr and shared_ptr in C++?

What are the differences between unique_ptr and shared_ptr in C++?

In C++, unique_ptr is a smart pointer that owns a dynamically allocated object exclusively, meaning no other pointer can own it. In contrast, shared_ptr allows multiple pointers to share ownership of the same object, using reference counting to manage the object's lifetime.

When should I use unique_ptr instead of shared_ptr?

You should use unique_ptr when you want sole ownership of an object and want to ensure that it is deleted when the unique_ptr goes out of scope. It's more efficient in terms of memory and performance since it doesn't involve reference counting.

Are there any performance implications of using shared_ptr?

Yes, shared_ptr has some overhead due to reference counting. Every time a shared_ptr is copied or assigned, the reference count must be updated, which can lead to performance issues in scenarios with frequent ownership changes.

Can I convert a unique_ptr to a shared_ptr?

Yes, you can convert a unique_ptr to a shared_ptr using the std::move function. However, this transfers ownership, and the unique_ptr will no longer own the object after the conversion.