#[derive(Debug, PartialEq, Eq)] enum DivisionError { // Example: 42 / 0 DivideByZero, // Only case for `i64`: `i64::MIN / -1` because the result is `i64::MAX + 1` IntegerOverflow, // Example: 5 / 2 = 2.5 NotDivisible, } // TODO: Calculate `a` divided by `b` if `a` is evenly divisible by `b`. // Otherwise, return a suitable error. fn divide(a: i64, b: i64) -> Result<i64, DivisionError> { todo!(); } // TODO: Add the correct return type and complete the function body. // Desired output: `Ok([1, 11, 1426, 3])` fn result_with_list() { let numbers = [27, 297, 38502, 81]; let division_results = numbers.into_iter().map(|n| divide(n, 27)); } // TODO: Add the correct return type and complete the function body. // Desired output: `[Ok(1), Ok(11), Ok(1426), Ok(3)]` fn list_of_results() { let numbers = [27, 297, 38502, 81]; let division_results = numbers.into_iter().map(|n| divide(n, 27)); } fn main() { // You can optionally experiment here. } #[cfg(test)] mod tests { use super::*; #[test] fn test_success() { assert_eq!(divide(81, 9), Ok(9)); } #[test] fn test_divide_by_0() { assert_eq!(divide(81, 0), Err(DivisionError::DivideByZero)); } #[test] fn test_integer_overflow() { assert_eq!(divide(i64::MIN, -1), Err(DivisionError::IntegerOverflow)); } #[test] fn test_not_divisible() { assert_eq!(divide(81, 6), Err(DivisionError::NotDivisible)); } #[test] fn test_divide_0_by_something() { assert_eq!(divide(0, 81), Ok(0)); } #[test] fn test_result_with_list() { assert_eq!(result_with_list().unwrap(), [1, 11, 1426, 3]); } #[test] fn test_list_of_results() { assert_eq!(list_of_results(), [Ok(1), Ok(11), Ok(1426), Ok(3)]); } }