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|
//@aux-build:proc_macro_derive.rs
#![allow(
unused,
dead_code,
clippy::needless_lifetimes,
clippy::needless_pass_by_value,
clippy::needless_arbitrary_self_type
)]
#![warn(clippy::extra_unused_lifetimes)]
#[macro_use]
extern crate proc_macro_derive;
fn empty() {}
fn used_lt<'a>(x: &'a u8) {}
fn unused_lt<'a>(x: u8) {}
//~^ extra_unused_lifetimes
fn unused_lt_transitive<'a, 'b: 'a>(x: &'b u8) {
// 'a is useless here since it's not directly bound
}
fn lt_return<'a, 'b: 'a>(x: &'b u8) -> &'a u8 {
panic!()
}
fn lt_return_only<'a>() -> &'a u8 {
panic!()
}
fn unused_lt_blergh<'a>(x: Option<Box<dyn Send + 'a>>) {}
trait Foo<'a> {
fn x(&self, a: &'a u8);
}
impl<'a> Foo<'a> for u8 {
fn x(&self, a: &'a u8) {}
}
struct Bar;
impl Bar {
fn x<'a>(&self) {}
//~^ extra_unused_lifetimes
}
// test for #489 (used lifetimes in bounds)
pub fn parse<'a, I: Iterator<Item = &'a str>>(_it: &mut I) {
unimplemented!()
}
pub fn parse2<'a, I>(_it: &mut I)
where
I: Iterator<Item = &'a str>,
{
unimplemented!()
}
struct X {
x: u32,
}
impl X {
fn self_ref_with_lifetime<'a>(&'a self) {}
fn explicit_self_with_lifetime<'a>(self: &'a Self) {}
}
// Methods implementing traits must have matching lifetimes
mod issue4291 {
trait BadTrait {
fn unused_lt<'a>(x: u8) {}
//~^ extra_unused_lifetimes
}
impl BadTrait for () {
fn unused_lt<'a>(_x: u8) {}
}
}
mod issue6437 {
pub struct Scalar;
impl<'a> std::ops::AddAssign<&Scalar> for &mut Scalar {
//~^ extra_unused_lifetimes
fn add_assign(&mut self, _rhs: &Scalar) {
unimplemented!();
}
}
impl<'b> Scalar {
//~^ extra_unused_lifetimes
pub fn something<'c>() -> Self {
//~^ extra_unused_lifetimes
Self
}
}
}
// https://github.com/rust-lang/rust-clippy/pull/8737#pullrequestreview-951268213
mod first_case {
use serde::de::Visitor;
pub trait Expected {
fn fmt(&self, formatter: &mut std::fmt::Formatter);
}
impl<'de, T> Expected for T
where
T: Visitor<'de>,
{
fn fmt(&self, formatter: &mut std::fmt::Formatter) {}
}
}
// https://github.com/rust-lang/rust-clippy/pull/8737#pullrequestreview-951268213
mod second_case {
pub trait Source {
fn hey();
}
// Should lint. The response to the above comment incorrectly called this a false positive. The
// lifetime `'a` can be removed, as demonstrated below.
impl<'a, T: Source + ?Sized + 'a> Source for Box<T> {
//~^ extra_unused_lifetimes
fn hey() {}
}
struct OtherBox<T: ?Sized>(Box<T>);
impl<T: Source + ?Sized> Source for OtherBox<T> {
fn hey() {}
}
}
// Should not lint
#[derive(ExtraLifetimeDerive)]
struct Human<'a> {
pub bones: i32,
pub name: &'a str,
}
// https://github.com/rust-lang/rust-clippy/issues/13578
mod issue_13578 {
pub trait Foo {}
impl<'a, T: 'a> Foo for Option<T> where &'a T: Foo {}
}
fn main() {}
|
