[SE-0143] Amend to explicitly allow conditional conformances to Hashable #808
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/cc @airspeedswift, @DougGregor (The alternative of course is to submit these conformances in a separate proposal.) |
DougGregor
reviewed
Mar 20, 2018
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Taking this amendment after core team discussion. |
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Following discussions on this forum thread, amend SE-0143 to explicitly include the adoption of conditional conformances for
Hashableby the following types:OptionalArrayArraySliceContiguousArrayDictionaryRangeClosedRangeThis involves a little bit more work than
Equatable: while we could make use of existing implementations of==forEquatable, none of these types currently implementhashValue.The above list intentionally does not include types whose
Hashableimplementation is even remotely controversial (such asSlice,AnyCollectionorAnySequence), or that don't already implementEquatable(such asCollectionOfOneorDictionaryLiteral).A draft implementation is available in swiftlang/swift#14527. (It is being updated in parallel to this PR; a version that's in line with this amendment will be available soon.)Update: See swiftlang/swift#15382 for the implementation.