parsable_enum.rs

macro_rules! parsable_enum {
    ($(#[$attrs:meta])* enum $name:ident { $($member:ident),*}) =>
        (parsable_enum! { $(#[$attrs])* enum $name { $($member),* ,}});
    ($(#[$attrs:meta])* enum $name:ident { $($member:ident),* , }) => {
        $(#[$attrs])*
        pub enum $name {
            $($member),+
        }

        use std::str::FromStr;
        impl FromStr for $name {
            type Err = String;
            fn from_str(s: &str) -> Result<Self, Self::Err> {
                match s {
                    $(stringify!($member) => Ok($name::$member)),+ ,
                    e => Err(e.into()),
                }
            }
        }
    }
}

parsable_enum! {
    #[derive(PartialEq, Eq, Debug)]
    enum Possible {
        A,
        B,
        C,
        D,
        E,
        F,
    }
}