Hello, Swift community.
The review of Hashable Conformance for Dictionary.Keys, CollectionOfOne and EmptyCollection ran from February 20th through March 6th, 2026.
Feedback was light but positive. A question was raised about why a conformance was being added to Dictionary.Keys but not .Values. This proposal is narrowly focused on adding “obvious and straightforward” missing conformances, and adding the conformance for .Values would require inventing the moral equivalent of a multiset, which is not yet present in the standard library. We think that this would be a good direction for future work, but is not necessary for this proposal to make sense. A short section has been added to alternatives considered to discuss this.
Accordingly, we have decided to accept SE-0514.
Thanks to everyone who participated in the review process.
Review Manager