tests/ui/async-await/issue-61076.rs

   1 // edition:2018
   2
   3 use core::future::Future;
   4 use core::pin::Pin;
   5 use core::task::{Context, Poll};
   6
   7 struct T;
   8
   9 struct Tuple(i32);
  10
  11 struct Struct {
  12     a: i32
  13 }
  14
  15 impl Struct {
  16     fn method(&self) {}
  17 }
  18
  19 impl Future for Struct {
  20     type Output = Struct;
  21     fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> { Poll::Pending }
  22 }
  23
  24 impl Future for Tuple {
  25     type Output = Tuple;
  26     fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> { Poll::Pending }
  27 }
  28
  29 impl Future for T {
  30     type Output = Result<(), ()>;
  31
  32     fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> {
  33         Poll::Pending
  34     }
  35 }
  36
  37 async fn foo() -> Result<(), ()> {
  38     Ok(())
  39 }
  40
  41 async fn bar() -> Result<(), ()> {
  42     foo()?; //~ ERROR the `?` operator can only be applied to values that implement `Try`
  43     //~^ NOTE the `?` operator cannot be applied to type `impl Future<Output = Result<(), ()>>`
  44     //~| HELP the trait `Try` is not implemented for `impl Future<Output = Result<(), ()>>`
  45     //~| HELP consider `await`ing on the `Future`
  46     //~| NOTE in this expansion of desugaring of operator `?`
  47     //~| NOTE in this expansion of desugaring of operator `?`
  48     //~| NOTE in this expansion of desugaring of operator `?`
  49     Ok(())
  50 }
  51
  52 async fn struct_() -> Struct {
  53     Struct { a: 1 }
  54 }
  55
  56 async fn tuple() -> Tuple {
  57     Tuple(1i32)
  58 }
  59
  60 async fn baz() -> Result<(), ()> {
  61     let t = T;
  62     t?; //~ ERROR the `?` operator can only be applied to values that implement `Try`
  63     //~^ NOTE the `?` operator cannot be applied to type `T`
  64     //~| HELP the trait `Try` is not implemented for `T`
  65     //~| HELP consider `await`ing on the `Future`
  66     //~| NOTE in this expansion of desugaring of operator `?`
  67     //~| NOTE in this expansion of desugaring of operator `?`
  68     //~| NOTE in this expansion of desugaring of operator `?`
  69
  70
  71     let _: i32 = tuple().0; //~ ERROR no field `0`
  72     //~^ HELP consider `await`ing on the `Future`
  73     //~| NOTE field not available in `impl Future`
  74
  75     let _: i32 = struct_().a; //~ ERROR no field `a`
  76     //~^ HELP consider `await`ing on the `Future`
  77     //~| NOTE field not available in `impl Future`
  78
  79     struct_().method(); //~ ERROR no method named
  80     //~^ NOTE method not found in `impl Future<Output = Struct>`
  81     //~| HELP consider `await`ing on the `Future`
  82     Ok(())
  83 }
  84
  85 async fn match_() {
  86     match tuple() { //~ HELP consider `await`ing on the `Future`
  87         //~^ NOTE this expression has type `impl Future<Output = Tuple>`
  88         Tuple(_) => {} //~ ERROR mismatched types
  89         //~^ NOTE expected future, found `Tuple`
  90         //~| NOTE expected opaque type `impl Future<Output = Tuple>`
  91     }
  92 }
  93
  94 fn main() {}