👀 Views: 61 💬 Answers: 1 📅 Created: 2025-06-02

rust warp async Rust

I'm building a feature where I've spent hours debugging this and I'm relatively new to this, so bear with me... I'm working with an scenario with returning an `async` function that uses `impl Trait` for a trait object in Rust... My goal is to create a simple server using `warp` that processes a request asynchronously and returns a custom type. Here's a simplified version of what I have: ```rust use warp::Filter; struct MyResponse { message: String } async fn handle_request() -> impl warp::Reply { MyResponse { message: String::from("Hello, world!") } } #[tokio::main] async fn main() { let route = warp::path::end() .and_then(handle_request); warp::serve(route).run(([127, 0, 0, 1], 3030)).await; } ``` However, when I try to run the server, I get the following behavior: ``` behavior[E0277]: the trait bound `MyResponse: warp::Reply` is not satisfied ``` I understand that `warp::Reply` is a trait that `MyResponse` needs to implement, but I'm unsure how to do this correctly when using `impl Trait`. I've also tried implementing the `warp::Reply` trait for `MyResponse` like this: ```rust impl warp::Reply for MyResponse { fn into_response(self) -> warp::http::Response<warp::hyper::Body> { warp::http::Response::new(warp::hyper::Body::from(self.message)) } } ``` But I still get the same behavior. I've checked the dependencies in `Cargo.toml` and I'm using `warp` version `0.3.1` and `tokio` version `1.1`. Any help on how to resolve this scenario would be greatly appreciated! What am I missing in my implementation? I'm working on a web app that needs to handle this. Thanks in advance! Thanks in advance!