Map builders do not expose methods to add elements without tupling

[NthPortal]

Scala 2.13.x

As noted by @smarter here, builders for Maps just use the regular Builder interface, and do not expose a way to add elements without creating tuples. However, several of the implementations (which are not publicly accessible) do have addOne methods taking key and value parameters.

[neontorrent]

What's more concerning to me is how Map creates a Tuple2 for every MapNode iteration, like map, foreach etc. for most Map implementation.

In HashMap, MapKeyValueTupleIterator creates a Tuple2 for every pair during iteration. So if you do a map on a HashMap with 1000 elements, it creates additional 1000 Tuple2 (if there is no collision because that's a different node impl)