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

What are the differences between shared_ptr and unique_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 shared_ptr instead of unique_ptr?

You should use shared_ptr when you need shared ownership of an object, such as when multiple parts of your program need to access the same resource. Use unique_ptr when you want to ensure that only one owner exists, which can help prevent memory leaks and improve performance.

Are there any performance implications of using shared_ptr?

Yes, shared_ptr has some overhead due to reference counting, which can lead to performance issues in high-frequency allocations. unique_ptr, being lightweight, is generally more efficient when exclusive ownership is sufficient.

Can I convert a unique_ptr to a shared_ptr?

Yes, you can convert a unique_ptr to a shared_ptr by using the std::move function to transfer ownership. This will create a new shared_ptr that shares ownership of the object previously owned by the unique_ptr.