26. Collecting into Option

Rust’s option implements FromIterator too!

Use it when you want to get None if there is a None element and values otherwise.

let cars = [Some("Porsche"), Some("Ferrari"), None];
let maybe_cars: Option<Vec<_>> = cars.into_iter().collect();
assert_eq!(maybe_cars, None);

or values …

let cars = [Some("Porsche"), Some("Ferrari"), Some("Skoda")];
let maybe_cars: Option<Vec<_>> = cars.into_iter().collect();
assert_eq!(maybe_cars, Some(vec!["Porsche", "Ferrari", "Skoda"]));