Perhaps a more direct Julia analogy would be the built-in AbstractArray interface. There is simply no question of how (to use their example) `mean(::CuArray; d

Perhaps a more direct Julia analogy would be the built-in AbstractArray interface. There is simply no question of how (to use their example) `mean(::CuArray; dims)` should work, it not only follows Base's notation, but extends the same `Statistics.mean` function, so that exotic arrays can be passed to packages written before the package defining them existed.