Multi-producer, single consumer hashset

What's the best DOTS option for a Hashset which can be written to from a single job on multiple threads?

I've seen people suggesting home-spun Native hashset collections, but it's unclear if those are still supported, or if they support writing the same hash value from multiple threads.

Elsewhere, people have suggested using a NativeMultiHashMap, then grabbing its keys. But that solution will result in multiple key entries. While not hard to work around, NativeMultiHashMap.GetKeyArray() can also be an expensive call.

What would you recommend is the best solution, here at the end of 2019?
Thank you for any advice.

 

https://jacksondunstan.com/articles/5346

 

NativeHashMap with empty struct as value (yeah is still 1 byte even if struct empty) it’s just simpler solution. Or write your own HashSet like from blog above.