rust-clippy/tests/ui/copy_iterator.rs

23 lines
530 B
Rust

#![warn(clippy::copy_iterator)]
#[derive(Copy, Clone)]
struct Countdown(u8);
impl Iterator for Countdown {
//~^ ERROR: you are implementing `Iterator` on a `Copy` type
//~| NOTE: consider implementing `IntoIterator` instead
type Item = u8;
fn next(&mut self) -> Option<u8> {
self.0.checked_sub(1).map(|c| {
self.0 = c;
c
})
}
}
fn main() {
let my_iterator = Countdown(5);
assert_eq!(my_iterator.take(1).count(), 1);
assert_eq!(my_iterator.count(), 5);
}