Smart Pointers & Interior Mutability

Smart pointers combine ownership with pointer-like behavior, while interior mutability provides controlled mutation through shared references.

Concepts

• Box
• Deref and DerefMut
• Rc
• RefCell
• Interior Mutability
• Cell
• Reference Cycles and Weak
• Cow

Patterns

• Weak Back References

Antipatterns

• Long-Lived RefCell Borrows

Neighboring Notes

Ownership · Borrowing · The Drop Trait · Arc · Shared State with Mutex · Deref Polymorphism Antipattern · Rc RefCell Overuse

Sources

• The Rust Programming Language, ch. 15 “Smart Pointers” - the-book, https://doc.rust-lang.org/book/ch15-00-smart-pointers.html
• Standard library, std::boxed, std::cell, std::rc, and std::borrow::Cow - std, https://doc.rust-lang.org/std/boxed/struct.Box.html https://doc.rust-lang.org/std/cell/index.html https://doc.rust-lang.org/std/rc/index.html https://doc.rust-lang.org/std/borrow/enum.Cow.html