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//@ edition:2018
//@compile-flags: --diagnostic-width=300
#![feature(coroutines, coroutine_trait, stmt_expr_attributes)]
use std::future::Future;
use std::ops::Coroutine;
async fn async_fn() {}
fn returns_async_block() -> impl Future<Output = ()> {
async {}
}
fn returns_coroutine() -> impl Coroutine<(), Yield = (), Return = ()> {
#[coroutine]
|| {
let _: () = yield ();
}
}
fn takes_future(_f: impl Future<Output = ()>) {}
fn takes_coroutine<ResumeTy>(_g: impl Coroutine<ResumeTy, Yield = (), Return = ()>) {}
fn main() {
// okay:
takes_future(async_fn());
takes_future(returns_async_block());
takes_future(async {});
takes_coroutine(returns_coroutine());
takes_coroutine(
#[coroutine]
|| {
let _: () = yield ();
},
);
// async futures are not coroutines:
takes_coroutine(async_fn());
//~^ ERROR the trait bound
takes_coroutine(returns_async_block());
//~^ ERROR the trait bound
takes_coroutine(async {});
//~^ ERROR the trait bound
// coroutines are not futures:
takes_future(returns_coroutine());
//~^ ERROR is not a future
takes_future(
#[coroutine]
|ctx| {
//~^ ERROR is not a future
ctx = yield ();
},
);
}
|
