errors4.rs
// errors4.rs
// Make this test pass! Execute `rustlings hint errors4` for hints :)
use std::cmp::Ordering::{Less, Equal, Greater};
#[derive(PartialEq, Debug)]
struct PositiveNonzeroInteger(u64);
#[derive(PartialEq, Debug)]
enum CreationError {
Negative,
Zero,
}
impl PositiveNonzeroInteger {
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
match value.cmp(&0) {
Less => Err(CreationError::Negative),
Equal => Err(CreationError::Zero),
Greater => Ok(PositiveNonzeroInteger(value as u64)),
}
}
}
#[test]
fn test_creation() {
assert!(PositiveNonzeroInteger::new(10).is_ok());
assert_eq!(
Err(CreationError::Negative),
PositiveNonzeroInteger::new(-10)
);
assert_eq!(Err(CreationError::Zero), PositiveNonzeroInteger::new(0));
}