Codableの実装初期PRでは、 KeyedDecodingContainerはKeyedDecodingContainerProtocolに準拠するけど、 KeyedEncodingContainerはKeyedEncodingContainerProtocolに準拠してない、と一貫性がなかったのを思い出した。 https://github.com/apple/swift/pull/9004#pullrequestreview-37206353 (edited)

Swift Archival & Serialization API by itaiferber · Pull Request #90...

What's in this pull request? Now that the core types introduced by SE-0166 have been sunk into the Swift standard library, the stdlib and compiler portions of #8124 and #8125 can be combine...