iirc, Ruby's array doesn't expose the distinction between length and capacity, but internally it may decide to amortize the cost of such copies. For example, if reject only removes a small % of elements, it may choose not to shrink capacity.
(That's assuming you copy at all, instead of simply updating the reference.)
iirc, Ruby's array doesn't expose the distinction between length and capacity, but internally it may decide to amortize the cost of such copies. For example, if reject only removes a small % of elements, it may choose not to shrink capacity.