src/tools/clippy/tests/ui/mut_mut.rs

   1 // aux-build:proc_macros.rs
   2 #![warn(clippy::mut_mut)]
   3 #![allow(unused)]
   4 #![allow(clippy::no_effect, clippy::uninlined_format_args, clippy::unnecessary_operation)]
   5
   6 extern crate proc_macros;
   7 use proc_macros::{external, inline_macros};
   8
   9 fn fun(x: &mut &mut u32) -> bool {
  10     **x > 0
  11 }
  12
  13 fn less_fun(x: *mut *mut u32) {
  14     let y = x;
  15 }
  16
  17 macro_rules! mut_ptr {
  18     ($p:expr) => {
  19         &mut $p
  20     };
  21 }
  22
  23 #[allow(unused_mut, unused_variables)]
  24 #[inline_macros]
  25 fn main() {
  26     let mut x = &mut &mut 1u32;
  27     {
  28         let mut y = &mut x;
  29     }
  30
  31     if fun(x) {
  32         let y: &mut &mut u32 = &mut &mut 2;
  33         **y + **x;
  34     }
  35
  36     if fun(x) {
  37         let y: &mut &mut &mut u32 = &mut &mut &mut 2;
  38         ***y + **x;
  39     }
  40
  41     let mut z = inline!(&mut $(&mut 3u32));
  42 }
  43
  44 fn issue939() {
  45     let array = [5, 6, 7, 8, 9];
  46     let mut args = array.iter().skip(2);
  47     for &arg in &mut args {
  48         println!("{}", arg);
  49     }
  50
  51     let args = &mut args;
  52     for arg in args {
  53         println!(":{}", arg);
  54     }
  55 }
  56
  57 fn issue6922() {
  58     // do not lint from an external macro
  59     external!(let mut_mut_ty: &mut &mut u32 = &mut &mut 1u32;);
  60 }
  61
  62 mod issue9035 {
  63     use std::fmt::Display;
  64
  65     struct Foo<'a> {
  66         inner: &'a mut dyn Display,
  67     }
  68
  69     impl Foo<'_> {
  70         fn foo(&mut self) {
  71             let hlp = &mut self.inner;
  72             bar(hlp);
  73         }
  74     }
  75
  76     fn bar(_: &mut impl Display) {}
  77 }