rustlings/exercises/options/options1.rs

40 lines
1.2 KiB
Rust

// options1.rs
// Execute `rustlings hint options1` or use the `hint` watch subcommand for a hint.
// I AM NOT DONE
// you can modify anything EXCEPT for this function's signature
fn print_number(maybe_number: Option<u16>) {
println!("printing: {}", maybe_number.unwrap());
}
// 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 :(
// TODO: Return an Option!
fn maybe_icecream(time_of_day: u16) -> Option<u16> {
// We use the 24-hour system here, so 10PM is a value of 22
// The Option output should gracefully handle cases where time_of_day > 24.
???
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn check_icecream() {
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 = maybe_icecream(12);
assert_eq!(icecreams, 5);
}
}