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rustlings-exercises-completed/exercises/options/options1.rs
2023-03-24 21:18:51 +00:00

41 lines
1.3 KiB
Rust

// options1.rs
// Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
// This function returns how much icecream there is left in the fridge.
// If it's before 10PM, there's 5 pieces left. At 10PM, someone eats them
// all, so there'll be no more left :(
fn maybe_icecream(time_of_day: u16) -> Option<u16> {
// We use the 24-hour system here, so 10PM is a value of 22 and 12AM is a value of 0
// The Option output should gracefully handle cases where time_of_day > 23.
// TODO: Complete the function body - remember to return an Option!
match time_of_day {
22..=23 => Some(0),
0..=21 => Some(5),
_ => None,
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn check_icecream() {
assert_eq!(maybe_icecream(9), Some(5));
assert_eq!(maybe_icecream(10), Some(5));
assert_eq!(maybe_icecream(23), Some(0));
assert_eq!(maybe_icecream(22), Some(0));
assert_eq!(maybe_icecream(25), None);
}
#[test]
fn raw_value() {
// TODO: Fix this test. How do you get at the value contained in the Option?
let icecreams = match maybe_icecream(12) {
Some(n) => n,
None => 0,
};
assert_eq!(icecreams, 5);
}
}