Macro for generating enums associated with values.
```Rust use valueenum::valueenum;
value_enum!( char => #[derive(Clone, Copy, PartialEq, Eq, Debug)] enum Abc { A = 'a', B = 'b', C = 'c', } );
asserteq!( char::from(Abc::A), 'a' ); asserteq!( Abc::try_from('b'), Ok(Abc::B) ); ```