sol2/include/sol/base_traits.hpp

// sol3

// The MIT License (MIT)

// Copyright (c) 2013-2020 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_BASE_TRAITS_HPP
#define SOL_BASE_TRAITS_HPP

#include <type_traits>

namespace sol {
	namespace detail {
		struct unchecked_t { };
		const unchecked_t unchecked = unchecked_t {};
	} // namespace detail

	namespace meta {
		using sfinae_yes_t = std::true_type;
		using sfinae_no_t = std::false_type;

		template <typename T>
		using void_t = void;

		template <typename T>
		using unqualified = std::remove_cv<std::remove_reference_t<T>>;

		template <typename T>
		using unqualified_t = typename unqualified<T>::type;

		namespace meta_detail {
			template <typename T>
			struct unqualified_non_alias : unqualified<T> { };

			template <template <class...> class Test, class, class... Args>
			struct is_detected : std::false_type { };

			template <template <class...> class Test, class... Args>
			struct is_detected<Test, void_t<Test<Args...>>, Args...> : std::true_type { };
		} // namespace meta_detail

		template <template <class...> class Trait, class... Args>
		using is_detected = typename meta_detail::is_detected<Trait, void, Args...>::type;

		template <template <class...> class Trait, class... Args>
		constexpr inline bool is_detected_v = is_detected<Trait, Args...>::value;

		template <std::size_t I>
		using index_value = std::integral_constant<std::size_t, I>;

		template <bool>
		struct conditional {
			template <typename T, typename U>
			using type = T;
		};

		template <>
		struct conditional<false> {
			template <typename T, typename U>
			using type = U;
		};

		template <bool B, typename T, typename U>
		using conditional_t = typename conditional<B>::template type<T, U>;

		namespace meta_detail {
			template <typename T, template <typename...> class Templ>
			struct is_specialization_of : std::false_type { };
			template <typename... T, template <typename...> class Templ>
			struct is_specialization_of<Templ<T...>, Templ> : std::true_type { };
		} // namespace meta_detail

		template <typename T, template <typename...> class Templ>
		using is_specialization_of = meta_detail::is_specialization_of<std::remove_cv_t<T>, Templ>;

		template <typename T, template <typename...> class Templ>
		inline constexpr bool is_specialization_of_v = is_specialization_of<std::remove_cv_t<T>, Templ>::value;

		template <typename T>
		struct identity {
			typedef T type;
		};

		template <typename T>
		using identity_t = typename identity<T>::type;

		template <typename T>
		using is_builtin_type = std::integral_constant<bool, std::is_arithmetic<T>::value || std::is_pointer<T>::value || std::is_array<T>::value>;

	} // namespace meta
} // namespace sol

#endif // SOL_BASE_TRAITS_HPP