Ace the Rust Interview

Enter your book access code

The curriculum, drills, tutor, and interviewer mode are for readers of Ace the Rust Interview. The code is printed in the Preface (Companion site access).

Don’t have the book yet? The landing page stays open — purchase unlocks this gym.

beginner · order 17

filter on Option

opt-filter-01Related book chapters: 2 (optional — this page is complete on its own)Optionfilter

Slug: opt-filter-01 · Paired reading: Chapter 2

Prompt

fn positive(n: Option<i32>) -> Option<i32> — keep Some only when the value is > 0, via Option::filter.