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Diffstat (limited to '')
-rw-r--r-- | src/tools/clippy/tests/ui/let_underscore_must_use.rs | 95 |
1 files changed, 95 insertions, 0 deletions
diff --git a/src/tools/clippy/tests/ui/let_underscore_must_use.rs b/src/tools/clippy/tests/ui/let_underscore_must_use.rs new file mode 100644 index 000000000..1edb77c74 --- /dev/null +++ b/src/tools/clippy/tests/ui/let_underscore_must_use.rs @@ -0,0 +1,95 @@ +#![warn(clippy::let_underscore_must_use)] +#![allow(clippy::unnecessary_wraps)] + +// Debug implementations can fire this lint, +// so we shouldn't lint external macros +#[derive(Debug)] +struct Foo { + field: i32, +} + +#[must_use] +fn f() -> u32 { + 0 +} + +fn g() -> Result<u32, u32> { + Ok(0) +} + +#[must_use] +fn l<T>(x: T) -> T { + x +} + +fn h() -> u32 { + 0 +} + +struct S; + +impl S { + #[must_use] + pub fn f(&self) -> u32 { + 0 + } + + pub fn g(&self) -> Result<u32, u32> { + Ok(0) + } + + fn k(&self) -> u32 { + 0 + } + + #[must_use] + fn h() -> u32 { + 0 + } + + fn p() -> Result<u32, u32> { + Ok(0) + } +} + +trait Trait { + #[must_use] + fn a() -> u32; +} + +impl Trait for S { + fn a() -> u32 { + 0 + } +} + +fn main() { + let _ = f(); + let _ = g(); + let _ = h(); + let _ = l(0_u32); + + let s = S {}; + + let _ = s.f(); + let _ = s.g(); + let _ = s.k(); + + let _ = S::h(); + let _ = S::p(); + + let _ = S::a(); + + let _ = if true { Ok(()) } else { Err(()) }; + + let a = Result::<(), ()>::Ok(()); + + let _ = a.is_ok(); + + let _ = a.map(|_| ()); + + let _ = a; + + #[allow(clippy::let_underscore_must_use)] + let _ = a; +} |