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use std::ops::Mul;
#[derive(Clone, Copy, Serialize, Deserialize, Debug, PartialEq, Eq)]
pub enum Card {
Null,
Finite(usize),
Infinite,
}
impl Mul for Card {
type Output = Card;
fn mul(self, rhs: Card) -> Card {
match self {
Card::Null => rhs,
Card::Infinite => self,
Card::Finite(ls) => match rhs {
Card::Null => self,
Card::Infinite => rhs,
Card::Finite(rs) => Card::Finite(ls * rs),
},
}
}
}
impl Into<usize> for Card {
fn into(self) -> usize {
match self {
Card::Finite(e) => e,
_ => panic!("Card type has no integer representation."),
}
}
}
#[cfg(test)]
mod tests {
use super::Card;
#[test]
fn test_equality() {
assert_eq!(Card::Null, Card::Null);
assert_eq!(Card::Infinite, Card::Infinite);
assert_eq!(Card::Finite(1), Card::Finite(1));
assert_eq!(Card::Finite(5), Card::Finite(5));
assert_eq!(Card::Finite(10), Card::Finite(10));
}
#[test]
fn test_inequality() {
assert_ne!(Card::Null, Card::Infinite);
assert_ne!(Card::Null, Card::Finite(1));
assert_ne!(Card::Infinite, Card::Null);
assert_ne!(Card::Infinite, Card::Finite(1));
assert_ne!(Card::Finite(1), Card::Null);
assert_ne!(Card::Finite(1), Card::Infinite);
assert_ne!(Card::Finite(1), Card::Finite(10));
}
#[test]
fn test_mul() {
assert_eq!(Card::Null * Card::Null, Card::Null);
assert_eq!(Card::Infinite * Card::Infinite, Card::Infinite);
assert_eq!(Card::Null * Card::Infinite, Card::Infinite);
assert_eq!(Card::Infinite * Card::Null, Card::Infinite);
assert_eq!(Card::Finite(1) * Card::Infinite, Card::Infinite);
assert_eq!(Card::Finite(5) * Card::Infinite, Card::Infinite);
assert_eq!(Card::Finite(1) * Card::Finite(1), Card::Finite(1));
assert_eq!(Card::Finite(1) * Card::Finite(5), Card::Finite(5));
assert_eq!(Card::Finite(5) * Card::Finite(1), Card::Finite(5));
assert_eq!(Card::Finite(5) * Card::Finite(5), Card::Finite(25));
}
#[test]
#[should_panic]
fn test_into_null() {
let s = Card::Null;
let _: usize = s.into();
}
#[test]
#[should_panic]
fn test_into_infinite() {
let s = Card::Infinite;
let _: usize = s.into();
}
#[test]
fn test_into_finite() {
for i in vec![1, 5, 10] {
let d = Card::Finite(i);
let v: usize = d.into();
assert_eq!(v, i);
}
}
}