diff --git a/clippy_lints/src/mut_mut.rs b/clippy_lints/src/mut_mut.rs index 75b8aa9c90cc..588afd85afb0 100644 --- a/clippy_lints/src/mut_mut.rs +++ b/clippy_lints/src/mut_mut.rs @@ -14,19 +14,30 @@ /// Checks for instances of `mut mut` references. /// /// ### Why is this bad? - /// Multiple `mut`s don't add anything meaningful to the - /// source. This is either a copy'n'paste error, or it shows a fundamental - /// misunderstanding of references. + /// This is usually just a typo or a misunderstanding of how references work. /// /// ### Example /// ```no_run - /// # let mut y = 1; - /// let x = &mut &mut y; + /// let x = &mut &mut 1; + /// + /// let mut x = &mut 1; + /// let y = &mut x; + /// + /// fn foo(x: &mut &mut u32) {} + /// ``` + /// Use instead + /// ```no_run + /// let x = &mut 1; + /// + /// let mut x = &mut 1; + /// let y = &mut *x; // reborrow + /// + /// fn foo(x: &mut u32) {} /// ``` #[clippy::version = "pre 1.29.0"] pub MUT_MUT, pedantic, - "usage of double-mut refs, e.g., `&mut &mut ...`" + "usage of double mut-refs, e.g., `&mut &mut ...`" } impl_lint_pass!(MutMut => [MUT_MUT]);