hasPresence property

Implementation

bool get hasPresence {
  // NB. Map fields are represented as repeated message fields
  if (isRepeated) return false;
  return true;
  // TODO(sigurdm): to provide the correct semantics for non-optional proto3
  // fields would need something like the following:
  // return baseType.isMessage ||
  //   descriptor.proto3Optional ||
  //   parent.fileGen.descriptor.syntax == "proto2";
  //
  // This change would break any accidental uses of the proto3 hazzers, and
  // would require some clean-up.
  //
  // We could consider keeping hazzers for proto3-oneof fields. There they
  // seem useful and not breaking proto3 semantics, and dart protobuf uses it
  // for example in package:protobuf/src/protobuf/mixins/well_known.dart.
}