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/******************************************************************************
* ____ _ _____ *
* / ___| / \ | ___| C++ *
* | | / _ \ | |_ Actor *
* | |___ / ___ \| _| Framework *
* \____/_/ \_|_| *
* *
* Copyright 2011-2018 Dominik Charousset *
* *
* Distributed under the terms and conditions of the BSD 3-Clause License or *
* (at your option) under the terms and conditions of the Boost Software *
* License 1.0. See accompanying files LICENSE and LICENSE_ALTERNATIVE. *
* *
* If you did not receive a copy of the license files, see *
* http://opensource.org/licenses/BSD-3-Clause and *
* http://www.boost.org/LICENSE_1_0.txt. *
******************************************************************************/
#pragma once
#include <string>
#include "caf/detail/comparable.hpp"
namespace caf {
/// Represents "nothing", e.g., for clearing an `optional` by assigning `none`.
struct none_t : detail::comparable<none_t> {
constexpr none_t() {
// nop
}
constexpr explicit operator bool() const {
return false;
}
static constexpr int compare(none_t) {
return 0;
}
};
static constexpr none_t none = none_t{};
/// @relates none_t
inline std::string to_string(const none_t&) {
return "none";
}
} // namespace caf
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