use serde::Deserialize;
use serde_yaml::Value;

#[derive(Deserialize, Debug)]
enum EnumType {
    A,
    B,
    C,
}

#[derive(Deserialize, Debug)]
struct MyConfig {
    a: Option<String>,
    b: EnumType,
}

fn main() {
    let config_yml = "a: ...\nb: A\n";

    println!("{:?}", serde_yaml::from_str::<MyConfig>(config_yml).unwrap());
}