The optimized way for passing multidimensional numeric arrays from/to cpp

Hi,
I have a general question for passing multidimensional arrays to and from c++ code. Imagine we have the following array.

```
[[[long,long],[long,long],[long,long],[long,long],[long,long],[long,long]],[[long,long],[long,long],[long,long],[long,long],[long,long],[long,long]]]
```

What is the best approach to pass them between js and cpp? I can define a `vector>` object, but I need to define its js class each time, and I feel it can be memory-consuming for large arrays. Is there any better ways to manage numeric multi-dimensional arrays using `val` helper functions?