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Diffstat (limited to '')
-rw-r--r-- | src/tools/clippy/tests/ui/extra_unused_lifetimes.rs | 129 |
1 files changed, 129 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/extra_unused_lifetimes.rs b/src/tools/clippy/tests/ui/extra_unused_lifetimes.rs new file mode 100644 index 000000000..d6631e012 --- /dev/null +++ b/src/tools/clippy/tests/ui/extra_unused_lifetimes.rs @@ -0,0 +1,129 @@ +// 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) {} + +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) {} +} + +// 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) {} + } + + impl BadTrait for () { + fn unused_lt<'a>(_x: u8) {} + } +} + +mod issue6437 { + pub struct Scalar; + + impl<'a> std::ops::AddAssign<&Scalar> for &mut Scalar { + fn add_assign(&mut self, _rhs: &Scalar) { + unimplemented!(); + } + } + + impl<'b> Scalar { + pub fn something<'c>() -> Self { + 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(); + } + + impl<'a, T: Source + ?Sized + 'a> Source for Box<T> { + fn hey() {} + } +} + +// Should not lint +#[derive(ExtraLifetimeDerive)] +struct Human<'a> { + pub bones: i32, + pub name: &'a str, +} + +fn main() {} |