performance of ndarray arithmetic operation

[tyghl]

i want to perform an Add operation and assign the result to another array.
like this:

result.assign(&(&arr1+ &arr2));

since i don't want to consume the data in arr1 and arr2, i think this method will always generate a temporary array, hence bad for performance.
So should i use iterator and add seperately in this case? Does any better solution exist?