// edition:2018 // check-pass async fn foo(arg: [u8; N]) -> usize { arg.len() } async fn bar() -> [u8; N] { [0; N] } trait Trait { fn fynn(&self) -> usize; } impl Trait for [u8; N] { fn fynn(&self) -> usize { N } } async fn baz() -> impl Trait { [0; N] } async fn biz(v: impl Trait) -> usize { v.fynn() } async fn user() { let _ = foo::(bar().await).await; let _ = biz(baz::().await).await; } fn main() { }