Function empty

Source/external/json.hpp:13878–13881

@brief return whether pointer points to the root document @sa https://json.nlohmann.me/api/json_pointer/empty/

	/// @brief return whether pointer points to the root document
	/// @sa https://json.nlohmann.me/api/json_pointer/empty/
	bool empty() const noexcept
	{
		return reference_tokens.empty();
	}

  private:
	/*!