Macro array
Source macro_rules! array {
(@accum (0, $($_es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (1, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (2, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (3, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (4, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (5, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (6, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (7, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (8, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (16, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (32, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@accum (64, $($es:expr),*) -> ($($body:tt)*)) => { ... };
(@as_expr $e:expr) => { ... };
[$e:expr; $n:tt] => { ... };
}