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|
#![warn(clippy::match_same_arms)]
#![allow(
clippy::disallowed_names,
clippy::diverging_sub_expression,
clippy::uninlined_format_args
)]
//@no-rustfix
fn bar<T>(_: T) {}
fn foo() -> bool {
unimplemented!()
}
fn match_same_arms() {
let _ = match 42 {
42 => {
//~^ ERROR: this match arm has an identical body to the `_` wildcard arm
foo();
let mut a = 42 + [23].len() as i32;
if true {
a += 7;
}
a = -31 - a;
a
},
_ => {
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: this match arm has an identical body to another arm
_ => true,
};
let _ = match Some(42) {
Some(_) => 24,
None => 24, //~ ERROR: this match arm has an identical body to another arm
};
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: this match arm has an identical body to another arm
_ => (),
}
match (Some(42), Some(42)) {
(Some(a), ..) => bar(a), //~ ERROR: this match arm has an identical body to another arm
(.., Some(a)) => bar(a),
_ => (),
}
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<i32, &str> = 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), //~ ERROR: this match arm has an identical body to another arm
(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"), //~ ERROR: this match arm has an identical body to another arm
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 => {
//~^ ERROR: this match arm has an identical body to another arm
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() {
let _ = match Some(0) {
Some(0) => 0,
Some(1) => 1,
#[cfg(feature = "foo")]
Some(2) => 2,
_ => 1,
};
enum Foo {
X(u32),
Y(u32),
Z(u32),
}
// Don't lint. `Foo::X(0)` and `Foo::Z(_)` overlap with the arm in between.
let _ = match Foo::X(0) {
Foo::X(0) => 1,
Foo::X(_) | Foo::Y(_) | Foo::Z(0) => 2,
Foo::Z(_) => 1,
_ => 0,
};
// Suggest moving `Foo::Z(_)` up.
let _ = match Foo::X(0) {
Foo::X(0) => 1, //~ ERROR: this match arm has an identical body to another arm
Foo::X(_) | Foo::Y(_) => 2,
Foo::Z(_) => 1,
_ => 0,
};
// Suggest moving `Foo::X(0)` down.
let _ = match Foo::X(0) {
Foo::X(0) => 1,
Foo::Y(_) | Foo::Z(0) => 2,
Foo::Z(_) => 1, //~ ERROR: this match arm has an identical body to another arm
_ => 0,
};
// Don't lint.
let _ = match 0 {
-2 => 1,
-5..=50 => 2,
-150..=88 => 1,
_ => 3,
};
struct Bar {
x: u32,
y: u32,
z: u32,
}
// Lint.
let _ = match None {
Some(Bar { x: 0, y: 5, .. }) => 1,
Some(Bar { y: 10, z: 0, .. }) => 2,
None => 50,
Some(Bar { y: 0, x: 5, .. }) => 1, //~ ERROR: this match arm has an identical body to another arm
_ => 200,
};
let _ = match 0 {
0 => todo!(),
1 => todo!(),
2 => core::convert::identity::<u32>(todo!()),
3 => core::convert::identity::<u32>(todo!()),
_ => 5,
};
let _ = match 0 {
0 => cfg!(not_enable),
1 => cfg!(not_enable),
_ => false,
};
}
|
