This is a hard one. Current NDArray already uses shared_ptr for other reasons, but every NDArray would have to keep track of its particular view into the array as well.

This might be possible by keeping a tuple of 'view semantics', which will be passed to xtv functions when set. Subsequent views would have to be concatenated into the first, probably requiring a special function, but it should be possible. Besides, just single-level views would already be tremendously useful on their own.

Alternatively, it might be possible to adapt xarray to make a custom subclass that already keeps track of strides. This might be considerably harder though.