Macro ast_enum_of_structs_impl

macro_rules! ast_enum_of_structs_impl {
    (
        $name:ident {
            $(
                $(#[cfg $cfg_attr:tt])*
                $(#[doc $($doc_attr:tt)*])*
                $variant:ident $( ($member:ident) )*,
            )*
        }
    ) => { ... };
}