// sol2

// The MIT License (MIT)

// Copyright (c) 2013-2021 Rapptz, ThePhD and contributors

// Permission is hereby granted, free of charge, to any person obtaining a copy of

// this software and associated documentation files (the "Software"), to deal in

// the Software without restriction, including without limitation the rights to

// use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of

// the Software, and to permit persons to whom the Software is furnished to do so,

// subject to the following conditions:

// The above copyright notice and this permission notice shall be included in all

// copies or substantial portions of the Software.

// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR

// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS

// FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR

// COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER

// IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN

// CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

#ifndef SOL_OPTIONAL_HPP

#define SOL_OPTIONAL_HPP

#include <sol/forward.hpp>

#include <sol/in_place.hpp>

#include <sol/traits.hpp>

#if SOL_IS_ON(SOL_USE_BOOST_I_)

#include <boost/optional.hpp>

#else

#include <sol/optional_implementation.hpp>

#endif // Boost vs. Better optional

#include <optional>

namespace sol {

#if SOL_IS_ON(SOL_USE_BOOST_I_)

template <typename T>

using optional = boost::optional<T>;

using nullopt_t = boost::none_t;

SOL_BOOST_NONE_CONSTEXPR_I_ nullopt_t nullopt = boost::none;

#endif // Boost vs. Better optional

namespace meta {

template <typename T>

using is_optional = any<is_specialization_of<T, optional>, is_specialization_of<T, std::optional>>;

template <typename T>

constexpr inline bool is_optional_v = is_optional<T>::value;

} // namespace meta

namespace detail {

template <typename T>

struct associated_nullopt {

inline static constexpr std::nullopt_t value = std::nullopt;

};

#if SOL_IS_ON(SOL_USE_BOOST_I_)

template <typename T>

struct associated_nullopt<boost::optional<T>> {

inline static SOL_BOOST_NONE_CONSTEXPR_I_ boost::none_t value = boost::none;

};

#endif // Boost nullopt

#if SOL_IS_ON(SOL_USE_BOOST_I_)

template <typename T>

inline SOL_BOOST_NONE_CONSTEXPR_I_ auto associated_nullopt_v = associated_nullopt<T>::value;

#else

template <typename T>

inline constexpr auto associated_nullopt_v = associated_nullopt<T>::value;

#endif // Boost continues to lag behind, to not many people's surprise...

} // namespace detail

} // namespace sol

#if SOL_IS_ON(SOL_USE_BOOST_I_)

#undef SOL_BOOST_NONE_CONSTEXPR_I_

#endif

#endif // SOL_OPTIONAL_HPP