Serializes this enum member by name.

For non-flags enums, the serialization is a JSON string. The value is the member name (see #to_s) transformed with String#underscore.

enum Stages
  INITIAL
  SECOND_STAGE
end

Stages::INITIAL.to_json      # => %("initial")
Stages::SECOND_STAGE.to_json # => %("second_stage")

For flags enums, the serialization is a JSON array including every flagged member individually serialized in the same way as a member of a non-flags enum. None is serialized as an empty array, All as an array containing all members.

@[Flags]
enum Sides
  LEFT
  RIGHT
end

Sides::LEFT.to_json                  # => %(["left"])
(Sides::LEFT | Sides::RIGHT).to_json # => %(["left","right"])
Sides::All.to_json                   # => %(["left","right"])
Sides::None.to_json                  # => %([])

ValueConverter.to_json offers a different serialization strategy based on the member value.