C++ (Cpp) not_null::add_position примеры использования

Пример #1

void
SpecialSecondOrderDifferentialEquation<Position>::SystemState::WriteToMessage(
        not_null<serialization::SystemState*> const message) const {
  for (auto const& position : positions) {
    position.WriteToMessage(message->add_position());
  }
  for (auto const& velocity : velocities) {
    velocity.WriteToMessage(message->add_velocity());
  }
  time.WriteToMessage(message->mutable_time());
}