35 lines
810 B
Rust
35 lines
810 B
Rust
// errors4.rs
|
|
//
|
|
// Execute `rustlings hint errors4` or use the `hint` watch subcommand for a
|
|
// hint.
|
|
|
|
|
|
#[derive(PartialEq, Debug)]
|
|
struct PositiveNonzeroInteger(u64);
|
|
|
|
#[derive(PartialEq, Debug)]
|
|
enum CreationError {
|
|
Negative,
|
|
Zero,
|
|
}
|
|
|
|
impl PositiveNonzeroInteger {
|
|
fn new(value: i64) -> Result<PositiveNonzeroInteger, CreationError> {
|
|
match value.signum() {
|
|
-1 => Err(CreationError::Negative),
|
|
0 => Err(CreationError::Zero),
|
|
_ => 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));
|
|
}
|