Legacy syntax “editions”. These pre-date editions, but behave much like distinct editions. These can’t be used to specify the edition of proto files, but feature definitions must supply proto2/proto3 defaults for backwards compatibility.
case proto2import SwiftProtobufSupport library for Swift code generated by protoc-gen-swift.
enum Google_Protobuf_EditionThe full set of known editions.
case unknownA placeholder for an unknown edition value.
case legacyA placeholder edition for specifying default behaviors before a feature was first introduced. This is effectively an “infinite past”.
case proto3case edition2023Editions that have been released. The specific values are arbitrary and should not be depended on, but they will always be time-ordered for easy comparison.
case edition2024case edition1TestOnlyPlaceholder editions for testing feature resolution. These should not be used or relied on outside of tests.
case edition2TestOnlycase edition99997TestOnlycase edition99998TestOnlycase edition99999TestOnlycase maxPlaceholder for specifying unbounded edition support. This should only ever be used by plugins that can expect to never require any changes to support a new edition.