macro_rules! impl_writeable_len_match {
($struct: ident, $cmp: tt, ($calc_len: expr), {$({$match: pat, $length: expr}),*}, {$($field:ident),*}) => {
impl Writeable for $struct {
macro_rules! impl_writeable_len_match {
($struct: ident, $cmp: tt, ($calc_len: expr), {$({$match: pat, $length: expr}),*}, {$($field:ident),*}) => {
impl Writeable for $struct {