rustlings/exercises/12_options/options2.rs

44 lines
1 KiB
Rust

// options2.rs
//
// Execute `rustlings hint options2` or use the `hint` watch subcommand for a
// hint.
fn main() {
// You can optionally experiment here.
}
#[cfg(test)]
mod tests {
#[test]
fn simple_option() {
let target = "rustlings";
let optional_target = Some(target);
// TODO: Make this an if let statement whose value is "Some" type
word = optional_target {
assert_eq!(word, target);
}
}
#[test]
fn layered_option() {
let range = 10;
let mut optional_integers: Vec<Option<i8>> = vec![None];
for i in 1..(range + 1) {
optional_integers.push(Some(i));
}
let mut cursor = range;
// TODO: make this a while let statement - remember that vector.pop also
// adds another layer of Option<T>. You can stack `Option<T>`s into
// while let and if let.
integer = optional_integers.pop() {
assert_eq!(integer, cursor);
cursor -= 1;
}
assert_eq!(cursor, 0);
}
}