rust-clippy/tests/ui/single_match.rs

#![warn(single_match)]

fn dummy() {
}

fn single_match(){
    let x = Some(1u8);

    match x {
        Some(y) => { println!("{:?}", y); }
        _ => ()
    };

    let z = (1u8,1u8);
    match z {
        (2...3, 7...9) => dummy(),
        _ => {}
    };

    // Not linted (pattern guards used)
    match x {
        Some(y) if y == 0 => println!("{:?}", y),
        _ => ()
    }

    // Not linted (no block with statements in the single arm)
    match z {
        (2...3, 7...9) => println!("{:?}", z),
        _ => println!("nope"),
    }
}

enum Foo { Bar, Baz(u8) }
use Foo::*;
use std::borrow::Cow;

fn single_match_know_enum() {
    let x = Some(1u8);
    let y : Result<_, i8> = Ok(1i8);

    match x {
        Some(y) => dummy(),
        None => ()
    };

    match y {
        Ok(y) => dummy(),
        Err(..) => ()
    };

    let c = Cow::Borrowed("");

    match c {
        Cow::Borrowed(..) => dummy(),
        Cow::Owned(..) => (),
    };

    let z = Foo::Bar;
    // no warning
    match z {
        Bar => println!("42"),
        Baz(_) => (),
    }

    match z {
        Baz(_) => println!("42"),
        Bar => (),
    }
}

fn main() { }