Closures and smart pointers in Rust

In Rust, closures are anonymous functions that can capture variables from their environment. Defined using pipes (|), closures are concise and flexible, enabling functional programming patterns. They are categorized by how they capture variables: Fn (immutable borrow), FnMut (mutable borrow), and FnOnce (ownership).

Smart pointers are advanced types managing memory and resources, offering capabilities beyond standard references. Key smart pointers include:

• Box<T>: For heap allocation.
• Rc<T>: Shared ownership in single-threaded contexts.
• Arc<T>: Shared ownership across threads.
• RefCell<T>: Runtime-checked mutable access.
• Mutex<T>: Thread-safe exclusive access.

Both closures and smart pointers enhance Rust's safety and flexibility, supporting powerful abstractions and memory management.