Summary
In this chapter, we have learned a few things about smart pointers.
std::unique_ptr<T> is a vocabulary type for ownership, and for ownership transfer; prefer it over raw T*. Consider the use of observer_ptr in situations where ownership is explicitly not being transferred, or where raw T* might be ambiguous to the reader.
std::shared_ptr<T> is a good (and standard) tool for dealing with shared ownership, where many different entities are all stakeholders in the lifetime of a single controlled object. std::weak_ptr<T> is a "ticket for shared_ptr"; it provides .lock() instead of operator*. If your class needs the ability to get shared_ptr to itself, inherit from std::enable_shared_from_this<T>. Remember to inherit publicly, and generally speaking, only at the leaves of your inheritance graph. And don't overuse these features in situations that do not absolutely require shared ownership!
Never touch raw pointers with your hands: use make_unique and make_shared to...
