Code shared from the Rust Playground

playground.rs

// Comented code work with nightly
//#![feature(type_alias_impl_trait)]

trait InterfaceThing {
    type Result: 'static;
    fn do_work() -> Self::Result;
}
struct Z{}

impl InterfaceThing for Z {
    // type Result = impl std::future::Future;
    type Result = Box<dyn std::future::Future<Output = u8>>;
    fn do_work() -> Self::Result {
        // async {5}
        Box::new(async {5})
    }
}

fn main() {

}