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