src/tools/clippy/tests/ui/manual_async_fn.fixed

   1 #![warn(clippy::manual_async_fn)]
   2 #![allow(clippy::needless_pub_self, unused)]
   3
   4 use std::future::Future;
   5
   6 async fn fut() -> i32 { 42 }
   7
   8 #[rustfmt::skip]
   9 async fn fut2() -> i32 { 42 }
  10
  11 #[rustfmt::skip]
  12 async fn fut3() -> i32 { 42 }
  13
  14 async fn empty_fut() {}
  15
  16 #[rustfmt::skip]
  17 async fn empty_fut2() {}
  18
  19 #[rustfmt::skip]
  20 async fn empty_fut3() {}
  21
  22 async fn core_fut() -> i32 { 42 }
  23
  24 // should be ignored
  25 fn has_other_stmts() -> impl core::future::Future<Output = i32> {
  26     let _ = 42;
  27     async move { 42 }
  28 }
  29
  30 // should be ignored
  31 fn not_fut() -> i32 {
  32     42
  33 }
  34
  35 // should be ignored
  36 async fn already_async() -> impl Future<Output = i32> {
  37     async { 42 }
  38 }
  39
  40 struct S;
  41 impl S {
  42     async fn inh_fut() -> i32 {
  43         // NOTE: this code is here just to check that the indentation is correct in the suggested fix
  44         let a = 42;
  45         let b = 21;
  46         if a < b {
  47             let c = 21;
  48             let d = 42;
  49             if c < d {
  50                 let _ = 42;
  51             }
  52         }
  53         42
  54     }
  55
  56     // should be ignored
  57     fn not_fut(&self) -> i32 {
  58         42
  59     }
  60
  61     // should be ignored
  62     fn has_other_stmts() -> impl core::future::Future<Output = i32> {
  63         let _ = 42;
  64         async move { 42 }
  65     }
  66
  67     // should be ignored
  68     async fn already_async(&self) -> impl Future<Output = i32> {
  69         async { 42 }
  70     }
  71 }
  72
  73 // Tests related to lifetime capture
  74
  75 async fn elided(_: &i32) -> i32 { 42 }
  76
  77 // should be ignored
  78 fn elided_not_bound(_: &i32) -> impl Future<Output = i32> {
  79     async { 42 }
  80 }
  81
  82 async fn explicit<'a, 'b>(_: &'a i32, _: &'b i32) -> i32 { 42 }
  83
  84 // should be ignored
  85 #[allow(clippy::needless_lifetimes)]
  86 fn explicit_not_bound<'a, 'b>(_: &'a i32, _: &'b i32) -> impl Future<Output = i32> {
  87     async { 42 }
  88 }
  89
  90 // should be ignored
  91 mod issue_5765 {
  92     use std::future::Future;
  93
  94     struct A;
  95     impl A {
  96         fn f(&self) -> impl Future<Output = ()> {
  97             async {}
  98         }
  99     }
 100
 101     fn test() {
 102         let _future = {
 103             let a = A;
 104             a.f()
 105         };
 106     }
 107 }
 108
 109 pub async fn issue_10450() -> i32 { 42 }
 110
 111 pub(crate) async fn issue_10450_2() -> i32 { 42 }
 112
 113 pub(self) async fn issue_10450_3() -> i32 { 42 }
 114
 115 fn main() {}