The appropriate way to think of it is as an optimization that you will almost certainly never need. If you do, you'd typically confirm that by profiling your code. And it would merely be one of several other strategies that you could employ to save a bit of memory and cpu. I'm sure there are some niche domains where every ms of performance matters enough that you'd go through a lot of trouble for very marginal gains in performance. But otherwise, this should not be something you'd ever need.