Set Operations on Set-like Containers

[Nordlöw via Digitalmars-d-learn]

Does

https://dlang.org/phobos/std_algorithm_setops.html

support specializations when (some) arguments are 
containers/ranges that provide the `in` operator?

Typically set- and map-like containers with O(1) key membership 
checking.

If not, should they?

And what about operator overloading for union (|), intersection 
(&) and difference (-)?