macro_rules! fed8 {
($a:ty, $b:ty, $c:ty, $d:ty, $e:ty, $f:ty, $g:ty, $h:ty) => { ... };
($a:ty, $b:ty, $c:ty, $d:ty, $e:ty, $f:ty, $g:ty, $h:ty; @without_children) => { ... };
($newtype:ty; $a:ty, $b:ty, $c:ty, $d:ty, $e:ty, $f:ty, $g:ty, $h:ty; @without_children) => { ... };
($newtype:ty; generic: $generic:ident; $($component:ty),*; $a:ty, $b:ty, $c:ty, $d:ty, $e:ty, $f:ty, $g:ty, $h:ty; @without_children) => { ... };
($newtype:ty; $a:ty, $b:ty, $c:ty, $d:ty, $e:ty, $f:ty, $g:ty, $h:ty) => { ... };
}