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#![warn(clippy::single_match)]
#![allow(
unused,
clippy::uninlined_format_args,
clippy::needless_if,
clippy::redundant_guards,
clippy::redundant_pattern_matching
)]
fn dummy() {}
fn single_match() {
let x = Some(1u8);
if let Some(y) = x {
println!("{:?}", y);
};
let x = Some(1u8);
if let Some(y) = x { println!("{:?}", y) }
let z = (1u8, 1u8);
if let (2..=3, 7..=9) = z { 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);
if let Some(y) = x { dummy() };
if let Ok(y) = y { dummy() };
let c = Cow::Borrowed("");
if let Cow::Borrowed(..) = c { dummy() };
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";
if x == "test" { println!() }
#[derive(PartialEq, Eq)]
enum Foo {
A,
B,
C(u32),
}
let x = Foo::A;
if x == Foo::A { println!() }
const FOO_C: Foo = Foo::C(0);
if x == FOO_C { println!() }
if x == Foo::A { println!() }
let x = &x;
if 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;
if let Bar::A = x { println!() }
// issue #7038
struct X;
let x = Some(X);
if let None = x { println!() };
}
// See: issue #8282
fn ranges() {
enum E {
V,
}
let x = (Some(E::V), Some(42));
// Don't lint, because the `E` enum can be extended with additional fields later. Thus, the
// proposed replacement to `if let Some(E::V)` may hide non-exhaustive warnings that appeared
// because of `match` construction.
match x {
(Some(E::V), _) => {},
(None, _) => {},
}
// lint
if let (Some(_), _) = x {}
// lint
if let (Some(E::V), _) = x { todo!() }
// lint
if let (.., Some(E::V), _) = (Some(42), Some(E::V), Some(42)) {}
// Don't lint, see above.
match (Some(E::V), Some(E::V), Some(E::V)) {
(.., Some(E::V), _) => {},
(.., None, _) => {},
}
// Don't lint, see above.
match (Some(E::V), Some(E::V), Some(E::V)) {
(Some(E::V), ..) => {},
(None, ..) => {},
}
// Don't lint, see above.
match (Some(E::V), Some(E::V), Some(E::V)) {
(_, Some(E::V), ..) => {},
(_, None, ..) => {},
}
}
fn skip_type_aliases() {
enum OptionEx {
Some(i32),
None,
}
enum ResultEx {
Err(i32),
Ok(i32),
}
use OptionEx::{None, Some};
use ResultEx::{Err, Ok};
// don't lint
match Err(42) {
Ok(_) => dummy(),
Err(_) => (),
};
// don't lint
match Some(1i32) {
Some(_) => dummy(),
None => (),
};
}
macro_rules! single_match {
($num:literal) => {
match $num {
15 => println!("15"),
_ => (),
}
};
}
fn main() {
single_match!(5);
// Don't lint
let _ = match Some(0) {
#[cfg(feature = "foo")]
Some(10) => 11,
Some(x) => x,
_ => 0,
};
}
fn issue_10808(bar: Option<i32>) {
if let Some(v) = bar { unsafe {
let r = &v as *const i32;
println!("{}", *r);
} }
if let Some(v) = bar {
unsafe {
let r = &v as *const i32;
println!("{}", *r);
}
}
}
mod issue8634 {
struct SomeError(i32, i32);
fn foo(x: Result<i32, ()>) {
match x {
Ok(y) => {
println!("Yay! {y}");
},
Err(()) => {
// Ignore this error because blah blah blah.
},
}
}
fn bar(x: Result<i32, SomeError>) {
match x {
Ok(y) => {
println!("Yay! {y}");
},
Err(_) => {
// TODO: Process the error properly.
},
}
}
fn block_comment(x: Result<i32, SomeError>) {
match x {
Ok(y) => {
println!("Yay! {y}");
},
Err(_) => {
/*
let's make sure that this also
does not lint block comments.
*/
},
}
}
}
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