rust/tests/run-pass/ice_exacte_size.rs

#![deny(clippy::all)]

#[allow(dead_code)]
struct Foo;

impl Iterator for Foo {
    type Item = ();

    fn next(&mut self) -> Option<()> {
        let _ = self.len() == 0;
        unimplemented!()
    }
}

impl ExactSizeIterator for Foo {}

fn main() {}