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#![warn(clippy::single_match)]
fn dummy() {}
fn single_match() {
let x = Some(1u8);
match x {
Some(y) => {
println!("{:?}", y);
},
_ => (),
};
let x = Some(1u8);
match x {
// Note the missing block braces.
// We suggest `if let Some(y) = x { .. }` because the macro
// is expanded before we can do anything.
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 std::borrow::Cow;
use Foo::*;
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 => (),
}
}
// issue #173
fn if_suggestion() {
let x = "test";
match x {
"test" => println!(),
_ => (),
}
#[derive(PartialEq, Eq)]
enum Foo {
A,
B,
C(u32),
}
let x = Foo::A;
match x {
Foo::A => println!(),
_ => (),
}
const FOO_C: Foo = Foo::C(0);
match x {
FOO_C => println!(),
_ => (),
}
match &&x {
Foo::A => println!(),
_ => (),
}
let x = &x;
match &x {
Foo::A => println!(),
_ => (),
}
enum Bar {
A,
B,
}
impl PartialEq for Bar {
fn eq(&self, rhs: &Self) -> bool {
matches!((self, rhs), (Self::A, Self::A) | (Self::B, Self::B))
}
}
impl Eq for Bar {}
let x = Bar::A;
match x {
Bar::A => println!(),
_ => (),
}
}
macro_rules! single_match {
($num:literal) => {
match $num {
15 => println!("15"),
_ => (),
}
};
}
fn main() {
single_match!(5);
}
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