Implement TryFrom in Rust
Rust interview exercise on Traits & Generics, difficulty 3 of 3. Solve it in the editor beside a worked example, or cold in Interview mode with the example hidden; the tests run the moment you do.
Implement TryFrom<&str> for Rgb so "#ff8000" becomes Rgb { r: 255, g: 128, b: 0 }. Errors are Strings, checked in this order: "missing #", then "expected 6 hex digits" (wrong length), then "invalid hex digit". Implementing TryFrom also makes "#000000".try_into() work.
Each exercise pairs a worked example with a twin problem to solve in a real editor; the tests run the moment you do. Interview mode hides the example: solve it from memory, without the hint or the solution, and it counts as solved cold. Progress is saved in your browser, and in your account if you sign in.