The problem/use-case that the feature addresses

The user only wants to view the result of the intersection or union and does not want to store it.

Alternatives you've considered

I think the reasons for support are as follows:

1. Unification at the API level, such as sinter/sunion
2. Using lua to achieve the same function requires three commands, which is expensive.

Additional information

In this post, antirez explained that zinter/zunion can be replaced by z[inter/union]store + zrange + del: https://groups.google.com/forum/#!topic/redis-db/ku0bCxxcMis