Backport of the ArraySet implementation from Android Marshmallow. Functionally, it's nearly identical to the original code, with some minor tweaks to use the same structure that ArrayMap uses to support older version.
My hope is that Google will eventually put ArraySet in the support library like they did with ArrayMap.
(From the AOSP documentation)
ArraySet is a generic set data structure that is designed to be more memory efficient than a traditional HashSet. The design is very similar to ArrayMap, with all of the caveats described there. This implementation is separate from ArrayMap, however, so the Object array contains only one item for each entry in the set (instead of a pair for a mapping).
Note that this implementation is not intended to be appropriate for data structures that may contain large numbers of items. It is generally slower than a traditional HashSet, since lookups require a binary search and adds and removes require inserting and deleting entries in the array. For containers holding up to hundreds of items, the performance difference is not significant, less than 50%.
Because this container is intended to better balance memory use, unlike most other standard Java containers it will shrink its array as items are removed from it. Currently you have no control over this shrinking -- if you set a capacity and then remove an item, it may reduce the capacity to better match the current size. In the future an explicit call to set the capacity should turn off this aggressive shrinking behavior.
compile 'io.sweers.arraysetbackport:arraysetbackport:1.0.0'Snapshots of the development version are available in Sonatype's snapshots repository.
Copyright (C) 2016 Zac Sweers
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