Package flags provides a set of flags controlled by build tags.
LazyUnmarshalExtensions specifies whether to lazily unmarshal extensions.
Lazy extension unmarshaling validates the contents of message-valued extension fields at unmarshal time, but defers creating the message structure until the extension is first accessed.
const ProtoLegacy = protoLegacy
ProtoLegacy specifies whether to enable support for legacy functionality such as MessageSets, weak fields, and various other obscure behavior that is necessary to maintain backwards compatibility with proto1 or the pre-release variants of proto2 and proto3.
This is disabled by default unless built with the "protolegacy" tag.
WARNING: The compatibility agreement covers nothing provided by this flag. As such, functionality may suddenly be removed or changed at our discretion.