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I tend to agree with you. “Unordered” is very strange when clearly it is consistently “ordered” by some function(name, insertion_id) to facilitate low latency lookup.

The iteration order seems arbitrary to a human, but that is exclusively because function(name, insertion_id) is not optimized for a human. It seems strange to call the collection “unordered” because of how it appears to a human.

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Unordered simply means the order isn’t exposed, not that the bits have somehow literally fallen out of the computer and are scattered on the floor.

I remember trying to explain to someone that Java's List type was ordered, where they thought ordered meant sorted. Turns out, language is tough.

This often comes up for map types. C++ std::map and Python OrderedDict are both "ordered" but in very different senses of that word. People who wanted one but got the other will most likely be unhappy. Both do always work for "golden test" inputs, which will satisfy the sort of person who writes unit tests after finishing the software by picking inputs and then mutating the checked outputs until the test passes...

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