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//@revisions: edition2021 edition2024
//@[edition2021] edition:2021
//@[edition2024] edition:2024
// The output for humans should just highlight the whole span without showing
// the suggested replacement, but we also want to test that suggested
// replacement only removes one set of parentheses, rather than naïvely
// stripping away any starting or ending parenthesis characters—hence this
// test of the JSON error format.
#![feature(custom_inner_attributes)]
#![feature(closure_lifetime_binder)]
#![rustfmt::skip]
#![deny(clippy::unused_unit)]
#![allow(dead_code)]
#![allow(clippy::from_over_into)]
struct Unitter;
impl Unitter {
#[allow(clippy::no_effect)]
pub fn get_unit<F: Fn() -> (), G>(&self, f: F, _g: G) -> ()
//~^ unused_unit
//~| unused_unit
where G: Fn() -> () {
//~^ unused_unit
let _y: &dyn Fn() -> () = &f;
//~^ unused_unit
(); // this should not lint, as it's not in return type position
}
}
impl Into<()> for Unitter {
#[rustfmt::skip]
fn into(self) -> () {
//~^ unused_unit
()
//~^ unused_unit
}
}
trait Trait {
fn redundant<F: FnOnce() -> (), G, H>(&self, _f: F, _g: G, _h: H)
//~^ unused_unit
where
G: FnMut() -> (),
//~^ unused_unit
H: Fn() -> ();
//~^ unused_unit
}
impl Trait for Unitter {
fn redundant<F: FnOnce() -> (), G, H>(&self, _f: F, _g: G, _h: H)
//~^ unused_unit
where
G: FnMut() -> (),
//~^ unused_unit
H: Fn() -> () {}
//~^ unused_unit
}
fn return_unit() -> () { () }
//~^ unused_unit
//~| unused_unit
#[allow(clippy::needless_return)]
#[allow(clippy::never_loop)]
#[allow(clippy::unit_cmp)]
fn main() {
let u = Unitter;
assert_eq!(u.get_unit(|| {}, return_unit), u.into());
return_unit();
loop {
break();
//~^ unused_unit
}
return();
//~^ unused_unit
}
// https://github.com/rust-lang/rust-clippy/issues/4076
fn foo() {
macro_rules! foo {
(recv($r:expr) -> $res:pat => $body:expr) => {
$body
}
}
foo! {
recv(rx) -> _x => ()
}
}
#[rustfmt::skip]
fn test()->(){}
//~^ unused_unit
#[rustfmt::skip]
fn test2() ->(){}
//~^ unused_unit
#[rustfmt::skip]
fn test3()-> (){}
//~^ unused_unit
fn macro_expr() {
macro_rules! e {
() => (());
}
e!()
}
mod issue9748 {
fn main() {
let _ = for<'a> |_: &'a u32| -> () {};
}
}
mod issue9949 {
fn main() {
#[doc = "documentation"]
()
}
}
mod issue14577 {
trait Unit {}
impl Unit for () {}
#[allow(dependency_on_unit_never_type_fallback)]
fn bar() -> () {
//~[edition2021]^ unused_unit
panic!()
}
struct UnitStruct;
impl UnitStruct {
fn apply<F: for<'c> Fn(&'c mut Self)>(&mut self, f: F) {
todo!()
}
}
}
mod pr14962 {
#[allow(unused_parens)]
type UnusedParensButNoUnit = Box<dyn (Fn())>;
}
mod issue15035 {
trait Convert<T> {
fn from(value: T) -> Self;
}
impl Convert<u64> for () {
fn from(_value: u64) -> Self {}
}
fn handle<T: Convert<u64>>(value: u64) -> T {
Convert::from(value)
}
pub fn f() -> Option<bool> {
let result: Result<bool, u64> = Err(42);
// the `-> ()` is required for the inference of `handle`'s return type
result.map_err(|err| -> () { handle(err) }).ok()
}
}
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