use serde::Deserialize;
#[derive(Deserialize)]
struct Config {
bar: Option<String>,
}
fn main() {
match envy::prefixed("FOO_").from_env::<Config>() {
Ok(config) => println!("provided config.bar {:?}", config.bar),
Err(err) => println!("error parsing config from env: {}", err),
}
}