[amelius]

Ehh, relational databases already proved that "sets" are the true universal data structures. Anything can be built upon them, including (hash)maps.

[dragonwriter]

A relation is equivalent to a map from its key to its non-key attributes. (A hash-map is just an implementation detail in how a map/relation is implemented.)

So, really, that's not a different universal data structure.

[yxhuvud]

Well, and sets can be built by maps, so they are clearly of the same constructive strength in that regard.

[mamcx]

Any info about this, with examples?