Rust Crash Course - Ultimate

To use the value inside, you must handle both cases (usually with match or unwrap ). fn plus_one(x: Option<i32>) -> Option<i32> match x None => None, Some(i) => Some(i + 1),

Traits are also used as on generics. 17. Lifetimes (The Scary Part – Made Simple) Lifetimes ensure references are always valid. Usually, the compiler infers them (lifetime elision). Sometimes you must annotate.

fn main() let x = 5; // immutable // x = 6; // ERROR: cannot assign twice to immutable variable let mut y = 10; // mutable y = 11; // OK ultimate rust crash course

fn main() println!("Hello, Rust!");

largest

'a means “the returned reference lives at least as long as both inputs.”

Rust is famously loved for its memory safety, blazing speed, and excellent tooling. It’s also famously feared for its borrow checker and steep learning curve. This crash course strips away the complexity, giving you a mental model of Rust that works. To use the value inside, you must handle

For simple types (integers, booleans, etc.) that implement the Copy trait, assignment copies instead of moves.