Numpy supports masked arrays which is very useful for many use-cases. Are there any plans how a similar feature could be implemented for rust-ndarray?

My current idea would be to build a decorator which wraps an array and contains an additional mask object: struct MaskedArray<A, M>{ array: A, mask: M, }

The mask itself should be a trait (and/or enum?) to handle the following cases:

• empty (no elements are masked)
• hard mask: a bool array with the same shape as the data array (masking by coordinate)
• no-data value (masking by value)
• predicate (masking by value and/or coordinate)

The problem with this approach is that there is currently no array trait which is needed for the decorator pattern.