I agree with sibling commenter. If I need determinism, I choose the deterministic container. If I don’t know whether I need determinism or not, I don’t understa

I agree with sibling commenter. If I need determinism, I choose the deterministic container. If I don’t know whether I need determinism or not, I don’t understand the problem well enough yet. Regarding wanting your code to produce the same results from one run to the next, so do I, and I get this by using appropriate data structures. If iterating a map is producing non-deterministic results then I’m doing something wrong, because that means that the order of iteration matters. It’s just that it’s not that common in my code that this is the case. Where I need specific order, more often than not, a list (array/vector) has been a more appropriate structure. Sometimes an ordered map is indeed the correct structure, but ordered map doesn’t by itself give you the determinism you desire, you also need to ensure that the insertion order is itself deterministic and consistent between runs, and that the order is maintained during processing/data manipulation between insertion time and iteration time. Typically a better approach, in my opinion, is to process the data in whatever form makes sense (eg unordered) and then when you reach a point where order matters, that’s where you sort by the order you require, rather than trying to make sure that you insert in the correct order and don’t lose that order somewhere in the process. Of course it’s valid to think about the steps and say “if I use an ordered map, this set of operations maintains the order, so I can omit the sorting” and that’s a good optimisation, but that should, in my opinion, be a conscious decision based on analysis if the problem, your solution, and your requirements.