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