Summary

Summary

Chapter Key Takeaways

• Box<T> allocates on the heap with single ownership.
• Rc<T> and Arc<T> provide shared read ownership via reference counting.
• RefCell<T> provides interior mutability with runtime borrow checks.
• Mutex<T> and RwLock<T> provide thread-safe interior mutability.
• Weak<T> prevents reference count cycles.
• OnceLock / LazyLock (and OnceCell / LazyCell) cover one-time initialization without third-party crates.
• MaybeUninit<T> allows working with uninitialized memory safely before type invariants are established.