Macro enum_map

macro_rules! enum_map {
    (
        {
            $(
                {$variant:ident, $_type_name:ty}
            ),*
        },
        $object_store:expr,
        $var_name:ident,
        $func:expr
    ) => { ... };
    ($object_store:expr, |$var_name:ident| $func:expr) => { ... };
}