Procedural macro derive that mimics arg_enum! from clap

Usage

In Cargo.toml: toml [dependencies] arg_enum_proc_macro = "0.1"

In the rust code: ``` rust use argenumproc_macro::ArgEnum;

/// All the possible states of Foo

[derive(ArgEnum)]

pub enum Foo { /// Initial state Unk, /// Foo is on On, /// Foo is off Off, } ```