envy_app.rs

extern crate envy;
use std::env;

#[derive(Deserialize, Debug)]
struct Config {
  secret: String,
  coolfactor: f32,
  prize: Option<usize>
}

fn main() {
  match envy::from_env::<Config>() {
    Ok(config) => println!("{:#?}", config)
    Err(error) => panic!("{:#?}", error)
  }
}