#![warn(clippy::ignored_unit_patterns)]
#![allow(clippy::redundant_pattern_matching, clippy::single_match)]

fn foo() -> Result<(), ()> {
    unimplemented!()
}

fn main() {
    match foo() {
        Ok(()) => {},
        Err(()) => {},
    }
    if let Ok(()) = foo() {}
    let _ = foo().map_err(|()| todo!());
}