fn main() { // You can optionally experiment here. } #[cfg(test)] mod tests { #[test] fn simple_option() { let target = "rustlings"; let optional_target = Some(target); // TODO: Make this an if-let statement whose value is `Some`. word = optional_target { assert_eq!(word, target); } } #[test] fn layered_option() { let range = 10; let mut optional_integers: Vec<Option<i8>> = vec![None]; for i in 1..=range { optional_integers.push(Some(i)); } let mut cursor = range; // TODO: Make this a while-let statement. Remember that `Vec::pop()` // adds another layer of `Option`. You can do nested pattern matching // in if-let and while-let statements. integer = optional_integers.pop() { assert_eq!(integer, cursor); cursor -= 1; } assert_eq!(cursor, 0); } }