Rust for C-Programmers

19.9 Summary

Rust’s smart pointers provide a powerful toolkit for memory management:

• Box<T>: Exclusive heap allocation for flexible data structures and trait objects.
• Rc<T>: Shared ownership via reference counting in single-threaded contexts.
• Arc<T>: Thread-safe shared ownership across multiple threads, using atomic reference counting.
• Cell<T>, RefCell<T>, OnceCell<T>: Interior mutability tools for controlled mutation behind immutable references, with runtime checks.
• Weak<T>: Non-owning references to break cycles and avoid memory leaks.

Each smart pointer type addresses specific needs, allowing you to balance safety, performance, and flexibility. By choosing the right smart pointer for your scenario, you can write memory-safe Rust code that remains efficient and manageable, without the pitfalls common in lower-level languages like C.