// edition: 2021 | |
// build-fail | |
#![feature(impl_trait_in_assoc_type)] | |
use core::future::Future; | |
trait Recur { | |
type Recur: Future<Output = ()>; | |
fn recur(self) -> Self::Recur; | |
} | |
async fn recur(t: impl Recur) { | |
t.recur().await; | |
} | |
impl Recur for () { | |
type Recur = impl Future<Output = ()>; | |
fn recur(self) -> Self::Recur { | |
async move { recur(self).await; } | |
//~^ ERROR recursion in an async block requires boxing | |
} | |
} | |
fn main() { | |
recur(()); | |
} |