#![warn(clippy::match_same_arms)] #![allow(clippy::blacklisted_name)] fn bar(_: T) {} fn foo() -> bool { unimplemented!() } fn match_same_arms() { let _ = match 42 { 42 => { foo(); let mut a = 42 + [23].len() as i32; if true { a += 7; } a = -31 - a; a }, _ => { //~ ERROR match arms have same body foo(); let mut a = 42 + [23].len() as i32; if true { a += 7; } a = -31 - a; a }, }; let _ = match 42 { 42 => foo(), 51 => foo(), //~ ERROR match arms have same body _ => true, }; let _ = match Some(42) { Some(_) => 24, None => 24, //~ ERROR match arms have same body }; let _ = match Some(42) { Some(foo) => 24, None => 24, }; let _ = match Some(42) { Some(42) => 24, Some(a) => 24, // bindings are different None => 0, }; let _ = match Some(42) { Some(a) if a > 0 => 24, Some(a) => 24, // one arm has a guard None => 0, }; match (Some(42), Some(42)) { (Some(a), None) => bar(a), (None, Some(a)) => bar(a), //~ ERROR match arms have same body _ => (), } match (Some(42), Some(42)) { (Some(a), ..) => bar(a), (.., Some(a)) => bar(a), //~ ERROR match arms have same body _ => (), } let _ = match Some(()) { Some(()) => 0.0, None => -0.0, }; match (Some(42), Some("")) { (Some(a), None) => bar(a), (None, Some(a)) => bar(a), // bindings have different types _ => (), } let x: Result = Ok(3); // No warning because of the guard. match x { Ok(x) if x * x == 64 => println!("ok"), Ok(_) => println!("ok"), Err(_) => println!("err"), } // This used to be a false positive; see issue #1996. match x { Ok(3) => println!("ok"), Ok(x) if x * x == 64 => println!("ok 64"), Ok(_) => println!("ok"), Err(_) => println!("err"), } match (x, Some(1i32)) { (Ok(x), Some(_)) => println!("ok {}", x), (Ok(_), Some(x)) => println!("ok {}", x), _ => println!("err"), } // No warning; different types for `x`. match (x, Some(1.0f64)) { (Ok(x), Some(_)) => println!("ok {}", x), (Ok(_), Some(x)) => println!("ok {}", x), _ => println!("err"), } // False negative #2251. match x { Ok(_tmp) => println!("ok"), Ok(3) => println!("ok"), Ok(_) => println!("ok"), Err(_) => { unreachable!(); }, } // False positive #1390 macro_rules! empty { ($e:expr) => {}; } match 0 { 0 => { empty!(0); }, 1 => { empty!(1); }, x => { empty!(x); }, }; // still lint if the tokens are the same match 0 { 0 => { empty!(0); }, 1 => { empty!(0); }, x => { empty!(x); }, } match_expr_like_matches_macro_priority(); } fn match_expr_like_matches_macro_priority() { enum E { A, B, C, } let x = E::A; let _ans = match x { E::A => false, E::B => false, _ => true, }; } fn main() {}