Karoy Lorentey with the announcement:

The Swift Standard Library currently implements the three most essential general-purpose data structures: Array, Set and Dictionary. These are the right tool for a wide variety of use cases, and they are particularly well-suited for use as currency types. But sometimes, in order to efficiently solve a problem or to maintain an invariant, Swift programmers would benefit from a larger library of data structures.

We expect the Collections package to empower you to write faster and more reliable programs, with less effort.

This joins the Swift Algorithms and Swift Numerics packages in what is becoming a valuable, open source resource for Swift developers around the world to use.