mirror of
https://github.com/rust-lang/rust-clippy
synced 2024-12-11 22:02:55 +00:00
362 lines
6.5 KiB
Rust
362 lines
6.5 KiB
Rust
#![warn(clippy::single_match)]
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#![allow(
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unused,
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clippy::uninlined_format_args,
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clippy::needless_if,
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clippy::redundant_guards,
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clippy::redundant_pattern_matching,
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clippy::manual_unwrap_or_default
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)]
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fn dummy() {}
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fn single_match() {
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let x = Some(1u8);
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match x {
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Some(y) => {
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println!("{:?}", y);
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},
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_ => (),
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};
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let x = Some(1u8);
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match x {
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// Note the missing block braces.
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// We suggest `if let Some(y) = x { .. }` because the macro
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// is expanded before we can do anything.
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Some(y) => println!("{:?}", y),
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_ => (),
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}
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let z = (1u8, 1u8);
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match z {
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(2..=3, 7..=9) => dummy(),
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_ => {},
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};
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// Not linted (pattern guards used)
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match x {
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Some(y) if y == 0 => println!("{:?}", y),
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_ => (),
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}
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// Not linted (no block with statements in the single arm)
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match z {
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(2..=3, 7..=9) => println!("{:?}", z),
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_ => println!("nope"),
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}
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}
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enum Foo {
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Bar,
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Baz(u8),
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}
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use std::borrow::Cow;
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use Foo::*;
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fn single_match_know_enum() {
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let x = Some(1u8);
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let y: Result<_, i8> = Ok(1i8);
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match x {
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Some(y) => dummy(),
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None => (),
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};
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match y {
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Ok(y) => dummy(),
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Err(..) => (),
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};
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let c = Cow::Borrowed("");
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match c {
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Cow::Borrowed(..) => dummy(),
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Cow::Owned(..) => (),
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};
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let z = Foo::Bar;
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// no warning
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match z {
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Bar => println!("42"),
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Baz(_) => (),
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}
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match z {
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Baz(_) => println!("42"),
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Bar => (),
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}
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}
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// issue #173
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fn if_suggestion() {
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let x = "test";
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match x {
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"test" => println!(),
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_ => (),
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}
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#[derive(PartialEq, Eq)]
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enum Foo {
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A,
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B,
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C(u32),
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}
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let x = Foo::A;
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match x {
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Foo::A => println!(),
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_ => (),
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}
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const FOO_C: Foo = Foo::C(0);
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match x {
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FOO_C => println!(),
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_ => (),
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}
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match &&x {
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Foo::A => println!(),
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_ => (),
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}
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let x = &x;
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match &x {
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Foo::A => println!(),
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_ => (),
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}
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enum Bar {
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A,
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B,
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}
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impl PartialEq for Bar {
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fn eq(&self, rhs: &Self) -> bool {
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matches!((self, rhs), (Self::A, Self::A) | (Self::B, Self::B))
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}
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}
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impl Eq for Bar {}
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let x = Bar::A;
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match x {
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Bar::A => println!(),
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_ => (),
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}
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// issue #7038
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struct X;
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let x = Some(X);
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match x {
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None => println!(),
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_ => (),
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};
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}
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// See: issue #8282
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fn ranges() {
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enum E {
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V,
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}
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let x = (Some(E::V), Some(42));
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// Don't lint, because the `E` enum can be extended with additional fields later. Thus, the
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// proposed replacement to `if let Some(E::V)` may hide non-exhaustive warnings that appeared
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// because of `match` construction.
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match x {
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(Some(E::V), _) => {},
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(None, _) => {},
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}
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// lint
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match x {
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(Some(_), _) => {},
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(None, _) => {},
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}
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// lint
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match x {
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(Some(E::V), _) => todo!(),
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(_, _) => {},
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}
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// lint
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match (Some(42), Some(E::V), Some(42)) {
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(.., Some(E::V), _) => {},
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(..) => {},
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}
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// Don't lint, see above.
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match (Some(E::V), Some(E::V), Some(E::V)) {
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(.., Some(E::V), _) => {},
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(.., None, _) => {},
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}
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// Don't lint, see above.
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match (Some(E::V), Some(E::V), Some(E::V)) {
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(Some(E::V), ..) => {},
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(None, ..) => {},
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}
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// Don't lint, see above.
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match (Some(E::V), Some(E::V), Some(E::V)) {
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(_, Some(E::V), ..) => {},
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(_, None, ..) => {},
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}
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}
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fn skip_type_aliases() {
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enum OptionEx {
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Some(i32),
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None,
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}
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enum ResultEx {
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Err(i32),
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Ok(i32),
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}
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use OptionEx::{None, Some};
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use ResultEx::{Err, Ok};
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// don't lint
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match Err(42) {
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Ok(_) => dummy(),
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Err(_) => (),
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};
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// don't lint
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match Some(1i32) {
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Some(_) => dummy(),
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None => (),
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};
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}
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macro_rules! single_match {
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($num:literal) => {
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match $num {
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15 => println!("15"),
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_ => (),
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}
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};
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}
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fn main() {
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single_match!(5);
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// Don't lint
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let _ = match Some(0) {
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#[cfg(feature = "foo")]
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Some(10) => 11,
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Some(x) => x,
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_ => 0,
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};
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}
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fn issue_10808(bar: Option<i32>) {
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match bar {
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Some(v) => unsafe {
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let r = &v as *const i32;
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println!("{}", *r);
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},
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_ => {},
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}
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match bar {
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#[rustfmt::skip]
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Some(v) => {
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unsafe {
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let r = &v as *const i32;
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println!("{}", *r);
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}
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},
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_ => {},
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}
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}
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mod issue8634 {
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struct SomeError(i32, i32);
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fn foo(x: Result<i32, ()>) {
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match x {
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Ok(y) => {
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println!("Yay! {y}");
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},
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Err(()) => {
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// Ignore this error because blah blah blah.
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},
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}
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}
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fn bar(x: Result<i32, SomeError>) {
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match x {
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Ok(y) => {
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println!("Yay! {y}");
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},
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Err(_) => {
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// TODO: Process the error properly.
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},
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}
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}
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fn block_comment(x: Result<i32, SomeError>) {
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match x {
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Ok(y) => {
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println!("Yay! {y}");
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},
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Err(_) => {
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/*
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let's make sure that this also
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does not lint block comments.
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*/
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},
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}
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}
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}
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fn issue11365() {
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enum Foo {
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A,
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B,
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C,
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}
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use Foo::{A, B, C};
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match Some(A) {
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Some(A | B | C) => println!(),
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None => {},
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}
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match Some(A) {
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Some(A | B) => println!(),
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Some { 0: C } | None => {},
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}
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match [A, A] {
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[A, _] => println!(),
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[_, A | B | C] => {},
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}
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match Ok::<_, u32>(Some(A)) {
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Ok(Some(A)) => println!(),
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Err(_) | Ok(None | Some(B | C)) => {},
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}
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match Ok::<_, u32>(Some(A)) {
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Ok(Some(A)) => println!(),
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Err(_) | Ok(None | Some(_)) => {},
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}
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match &Some(A) {
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Some(A | B | C) => println!(),
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None => {},
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}
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match &Some(A) {
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&Some(A | B | C) => println!(),
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None => {},
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}
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match &Some(A) {
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Some(A | B) => println!(),
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None | Some(_) => {},
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}
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}
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