Rust Ownership Skill
Ownership Rules
- •Each value has exactly one owner
- •When owner goes out of scope, value is dropped
- •Values can be moved or borrowed
Borrowing Rules
- •One mutable reference OR any number of immutable references
- •References must always be valid
rust
let s = String::from("hello");
let r1 = &s; // OK
let r2 = &s; // OK
let r3 = &mut s; // ERROR: can't borrow as mutable
Lifetimes
rust
fn longest<'a>(x: &'a str, y: &'a str) -> &'a str {
if x.len() > y.len() { x } else { y }
}
Review Severity
- •CRITICAL: Dangling references, use after move
- •MAJOR: Unnecessary clones, incorrect lifetime annotations
- •MINOR: Could use references instead of owned values