adtensor
macro_rules! tnsr { ($t:ty; $n:ty; $l:ty) => { ... }; ($t:ty; $n1:ty $(, $ntail:ty)*; RMaj) => { ... }; ($t:ty; $n2:ty, $n1:ty; CMaj) => { ... }; ($t:ty; $n2:ty, $n1:ty $(, $ntail:ty)*; CMaj) => { ... }; }