macro_rules! ascii_compatible_two_byte_decoder_function {
    ($lead:block,
     $trail:block,
     $slf:ident,
     $non_ascii:ident,
     $byte:ident,
     $lead_minus_offset:ident,
     $unread_handle_trail:ident,
     $source:ident,
     $handle:ident,
     $outermost:tt,
     $copy_ascii:ident,
     $destination_check:ident,
     $name:ident,
     $code_unit:ty,
     $dest_struct:ident,
     $ascii_punctuation:expr) => { ... };
}