None.hpp

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/*
 * Copyright (C) 2017-2026 The ESPResSo project
 *
 * This file is part of ESPResSo.
 *
 * ESPResSo is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * ESPResSo is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
 
#pragma once
 
#include <boost/serialization/access.hpp>
 
#include <cstddef>
 
namespace ScriptInterface {
 
/**
 * @brief Type to indicate no value in Variant.
 */
class None {
public:
  constexpr None() = default;
  constexpr None(std::nullptr_t) {}
 
  constexpr bool operator==(None const &) const { return true; }
  constexpr bool operator!=(None const &) const { return false; }
  constexpr bool operator<(None const &) const { return false; }
 
  constexpr operator bool() const { return false; }
 
private:
  friend boost::serialization::access;
  template <typename Archive>
  void serialize(Archive &, long int /* version */) const {}
};
} // namespace ScriptInterface