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|
// edition:2018
use core::future::Future;
use core::pin::Pin;
use core::task::{Context, Poll};
struct T;
struct Tuple(i32);
struct Struct {
a: i32
}
impl Struct {
fn method(&self) {}
}
impl Future for Struct {
type Output = Struct;
fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> { Poll::Pending }
}
impl Future for Tuple {
type Output = Tuple;
fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> { Poll::Pending }
}
impl Future for T {
type Output = Result<(), ()>;
fn poll(self: Pin<&mut Self>, _: &mut Context<'_>) -> Poll<Self::Output> {
Poll::Pending
}
}
async fn foo() -> Result<(), ()> {
Ok(())
}
async fn bar() -> Result<(), ()> {
foo()?; //~ ERROR the `?` operator can only be applied to values that implement `Try`
//~^ NOTE the `?` operator cannot be applied to type `impl Future<Output = Result<(), ()>>`
//~| HELP the trait `Try` is not implemented for `impl Future<Output = Result<(), ()>>`
//~| HELP consider `await`ing on the `Future`
//~| NOTE in this expansion of desugaring of operator `?`
//~| NOTE in this expansion of desugaring of operator `?`
//~| NOTE in this expansion of desugaring of operator `?`
Ok(())
}
async fn struct_() -> Struct {
Struct { a: 1 }
}
async fn tuple() -> Tuple {
//~^ NOTE checked the `Output` of this `async fn`, expected opaque type
//~| NOTE while checking the return type of the `async fn`
//~| NOTE in this expansion of desugaring of `async` block or function
Tuple(1i32)
}
async fn baz() -> Result<(), ()> {
let t = T;
t?; //~ ERROR the `?` operator can only be applied to values that implement `Try`
//~^ NOTE the `?` operator cannot be applied to type `T`
//~| HELP the trait `Try` is not implemented for `T`
//~| HELP consider `await`ing on the `Future`
//~| NOTE in this expansion of desugaring of operator `?`
//~| NOTE in this expansion of desugaring of operator `?`
//~| NOTE in this expansion of desugaring of operator `?`
let _: i32 = tuple().0; //~ ERROR no field `0`
//~^ HELP consider `await`ing on the `Future`
//~| NOTE field not available in `impl Future`
let _: i32 = struct_().a; //~ ERROR no field `a`
//~^ HELP consider `await`ing on the `Future`
//~| NOTE field not available in `impl Future`
struct_().method(); //~ ERROR no method named
//~^ NOTE method not found in `impl Future<Output = Struct>`
//~| HELP consider `await`ing on the `Future`
Ok(())
}
async fn match_() {
match tuple() { //~ HELP consider `await`ing on the `Future`
//~^ NOTE this expression has type `impl Future<Output = Tuple>`
Tuple(_) => {} //~ ERROR mismatched types
//~^ NOTE expected opaque type, found struct `Tuple`
//~| NOTE expected opaque type `impl Future<Output = Tuple>`
}
}
fn main() {}
|
