// <json-one>
use actix_web::{web, App, Result};
use serde::Deserialize;

#[derive(Deserialize)]
struct Info {
    username: String,
}

/// deserialize `Info` from request's body
fn index(info: web::Json<Info>) -> Result<String> {
    Ok(format!("Welcome {}!", info.username))
}

pub fn main() {
    App::new().route("/", web::get().to(index));
}
// </json-one>