include/refl.hpp

// The MIT License (MIT)
//
// Copyright (c) 2020 Veselin Karaganev (@veselink1) 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
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// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
// SOFTWARE.

#ifndef REFL_INCLUDE_HPP
#define REFL_INCLUDE_HPP

#include <stddef.h> // size_t
#include <cstring>
#include <array>
#include <utility> // std::move, std::forward
#include <optional>
#include <tuple>
#include <type_traits>
#include <ostream>
#include <sstream>
#include <iomanip> // std::quoted
#include <memory>
#include <complex>

#ifdef _MSC_VER
// Disable VS warning for "Not enough arguments for macro"
// (emitted when a REFL_ macro is not provided any attributes)
#pragma warning( disable : 4003 )
#endif

#if defined(__clang__)
  #if __has_feature(cxx_rtti)
    #define REFL_RTTI_ENABLED
  #endif
#elif defined(__GNUG__)
  #if defined(__GXX_RTTI)
    #define REFL_RTTI_ENABLED
  #endif
#elif defined(_MSC_VER)
  #if defined(_CPPRTTI)
    #define REFL_RTTI_ENABLED
  #endif
#endif

/**
 * @brief The top-level refl-cpp namespace
 * It contains a few core refl-cpp namespaces and directly exposes core classes and functions.
 * <ul>
 * <li>util - utility functions (for_each, map_to_tuple, etc.)</li>
 * <li>trait - type-traits and other operations on types (is_function_v, map_t, etc.)</li>
 * <li>runtime - utility functions and classes that always have a runtime overhead (proxy<T>, debug_str, etc.)</li>
 * <li>member - contains the empty classes member and function (used for tagging)</li>
 * <li>descriptor - contains the non-specialized member types (type|field_descriptor<T, N>, and operations on them (get_property, get_display_name, etc.))</li>
 * </ul>
 *
 * using util::type_list; <br>
 * using descriptor::type_descriptor; <br>
 * using descriptor::field_descriptor; <br>
 * using descriptor::function_descriptor; <br>
 * using util::const_string; <br>
 * using util::make_const_string; <br>
 */
namespace refl
{
    /**
     * @brief Contains utility types and functions for working with those types.
     */
    namespace util
    {
        /**
         * Converts a compile-time available const char* value to a const_string<N>.
         * The argument must be a *core constant expression* and be null-terminated.
         *
         * @see refl::util::const_string
         */
#define REFL_MAKE_CONST_STRING(CString) \
    (::refl::util::detail::copy_from_unsized<::refl::util::detail::strlen(CString)>(CString))

        /**
         * Represents a compile-time string. Used in refl-cpp
         * for representing names of reflected types and members.
         * Supports constexpr concatenation and substring,
         * and is explicitly-convertible to const char* and std::string.
         * REFL_MAKE_CONST_STRING can be used to create an instance from a literal string.
         *
         * @typeparam <N> The length of the string excluding the terminating '\0' character.
         * @see refl::descriptor::base_member_descriptor::name
         */
        template <size_t N>
        struct const_string
        {
            /** The largest positive value size_t can hold. */
            static constexpr size_t npos = static_cast<size_t>(-1);

            /** The length of the string excluding the terminating '\0' character. */
            static constexpr size_t size = N;

            /**
             * The statically-sized character buffer used for storing the string.
             */
            char data[N + 1];

            /**
             * Creates an empty const_string.
             */
            constexpr const_string() noexcept
                : data{}
            {
            }

            /**
             * Creates a copy of a const_string.
             */
            constexpr const_string(const const_string<N>& other) noexcept
                : const_string(other, std::make_index_sequence<N>())
            {
            }

            /**
             * Creates a const_string by copying the contents of data.
             */
            constexpr const_string(const char(&data)[N + 1]) noexcept
                : const_string(data, std::make_index_sequence<N>())
            {
            }

            /**
             * Explicitly converts to const char*.
             */
            explicit constexpr operator const char*() const noexcept
            {
                return data;
            }

            /**
             * Explicitly converts to std::string.
             */
            explicit operator std::string() const noexcept
            {
                return data;
            }

            /**
             * Returns a pointer to the contained zero-terminated string.
             */
            constexpr const char* c_str() const noexcept
            {
                return data;
            }

            /**
             * Returns the contained string as an std::string.
             */
            std::string str() const noexcept
            {
                return data;
            }

            /**
             * A constexpr version of std::string::substr.
             *
             * \code{.cpp}
             * make_const_string("Hello, World!").template substr<0, 4>() -> (const_string<4>) "Hell"
             * make_const_string("Hello, World!").template substr<1, 4>() -> (const_string<3>) "ell"
             * \endcode
             */
            template <size_t Pos, size_t Count = npos>
            constexpr auto substr() const noexcept
            {
                static_assert(Pos <= N);
                constexpr size_t NewSize = (std::min)(Count, N - Pos);

                char buf[NewSize + 1]{};
                for (size_t i = 0; i < NewSize; i++) {
                    buf[i] = data[Pos + i];
                }

                return const_string<NewSize>(buf);
            }

            /**
             * Searches the string for the first occurrence of the character and returns its position.
             *
             * \code{.cpp}
             * make_const_string("Hello, World!").find('e') -> 1
             * make_const_string("Hello, World!").find('z') -> static_cast<size_t>(-1)
             * \endcode
             */
            constexpr auto find(char ch, size_t pos = 0) const noexcept
            {
                for (size_t i = pos; i < N; i++) {
                    if (data[i] == ch) {
                        return i;
                    }
                }
                return npos;
            }

            /**
             * Searches the string for the last occurrence of the character and returns its position.
             *
             * \code{.cpp}
             * make_const_string("Hello, World!").rfind('o') -> 8
             * make_const_string("Hello, World!").rfind('z') -> static_cast<size_t>(-1)
             * \endcode
             */
            constexpr auto rfind(char ch, size_t pos = npos) const noexcept
            {
                for (size_t i = (pos == npos ? N - 1 : pos); i + 1 > 0; i--) {
                    if (data[i] == ch) {
                        return i;
                    }
                }
                return npos;
            }

        private:

            /**
             * Creates a copy of a const_string.
             */
            template <size_t... Idx>
            constexpr const_string(const const_string<N>& other, std::index_sequence<Idx...>) noexcept
                : data{ other.data[Idx]... }
            {
            }

            /**
             * Creates a const_string by copying the contents of data.
             */
            template <size_t... Idx>
            constexpr const_string(const char(&data)[sizeof...(Idx) + 1], std::index_sequence<Idx...>) noexcept
                : data{ data[Idx]... }
            {
            }

        };

        /**
         * Creates an empty instance of const_string<N>
         *
         * @see refl::util::const_string
         */
        constexpr const_string<0> make_const_string() noexcept
        {
            return {};
        }

        /**
         * Creates an instance of const_string<N>
         *
         * @see refl::util::const_string
         */
        template <size_t N>
        constexpr const_string<N - 1> make_const_string(const char(&str)[N]) noexcept
        {
            return str;
        }

        /**
         * Creates an instance of const_string<N>
         *
         * @see refl::util::const_string
         */
        constexpr const_string<1> make_const_string(char ch) noexcept
        {
            const char str[2]{ ch, '\0' };
            return make_const_string(str);
        }

        /**
         * Concatenates two const_strings together.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr const_string<N + M> operator+(const const_string<N>& a, const const_string<M>& b) noexcept
        {
            char data[N + M + 1] { };
            for (size_t i = 0; i < N; i++)
                data[i] = a.data[i];
            for (size_t i = 0; i < M; i++)
                data[N + i] = b.data[i];
            return data;
        }

        /**
         * Concatenates a const_string with a C-style string.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr const_string<N + M - 1> operator+(const const_string<N>& a, const char(&b)[M]) noexcept
        {
            return a + make_const_string(b);
        }

        /**
         * Concatenates a C-style string with a const_string.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr const_string<N + M - 1> operator+(const char(&a)[N], const const_string<M>& b) noexcept
        {
            return make_const_string(a) + b;
        }

        /**
         * Compares two const_strings for equality.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr bool operator==(const const_string<N>& a, const const_string<M>& b) noexcept
        {
            if constexpr (N != M) {
                return false;
            }
            else {
                for (size_t i = 0; i < M; i++) {
                    if (a.data[i] != b.data[i]) {
                        return false;
                    }
                }
                return true;
            }
        }

        /**
         * Compares two const_strings for equality.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr bool operator!=(const const_string<N>& a, const const_string<M>& b) noexcept
        {
            return !(a == b);
        }

        /**
         * Compares a const_string with a C-style string for equality.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr bool operator==(const const_string<N>& a, const char(&b)[M]) noexcept
        {
            return a == make_const_string(b);
        }

        /**
         * Compares a const_string with a C-style string for equality.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr bool operator!=(const const_string<N>& a, const char(&b)[M]) noexcept
        {
            return a != make_const_string(b);
        }

        /**
         * Compares a C-style string with a const_string for equality.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr bool operator==(const char(&a)[N], const const_string<M>& b) noexcept
        {
            return make_const_string(a) == b;
        }

        /**
         * Compares a C-style string with a const_string for equality.
         *
         * @see refl::util::const_string
         */
        template <size_t N, size_t M>
        constexpr bool operator!=(const char(&a)[N], const const_string<M>& b) noexcept
        {
            return make_const_string(a) != b;
        }

        template <size_t N>
        constexpr std::ostream& operator<<(std::ostream& os, const const_string<N>& str) noexcept
        {
            return os << str.c_str();
        }

        namespace detail
        {
            constexpr size_t strlen(const char* const str)
            {
                return *str ? 1 + strlen(str + 1) : 0;
            }

            template <size_t N>
            constexpr const_string<N> copy_from_unsized(const char* const str)
            {
                const_string<N> cstr;
                for (size_t i = 0; i < N; i++) {
                    cstr.data[i] = str[i];
                }
                return cstr;
            }
        } // namespace detail

        /**
         * Represents a compile-time list of types provided as variadic template parameters.
         * type_list is an empty TrivialType. Instances of it can freely be created to communicate
         * the list of represented types. type_lists support many standard operations that are
         * implicitly available with ADL-lookup. type_list is used by refl-cpp mostly to represent
         * the list of refl::field_descriptor, refl::function_descriptor specializations that
         * allow the compile-time reflection of a type's members.
         *
         * @see refl::util::for_each
         * @see refl::util::map_to_array
         * @see refl::util::map_to_tuple
         * @see refl::member_list
         *
         * # Examples
         * ```
         * for_each(type_list<int, float>(), [](auto) { ... });
         * ```
         */
        template <typename... Ts>
        struct type_list
        {
            /** The number of types in this type_list */
            static constexpr intptr_t size = sizeof...(Ts);
        };

        template <typename T>
        struct type_list<T>
        {
            typedef T type;
            static constexpr intptr_t size = 1;
        };

        template <typename T>
        using type_tag = type_list<T>;

    } // namespace util

    using util::const_string;
    using util::make_const_string;
    using util::type_list;
    using util::type_tag;

    /**
     * The contents of the refl::detail::macro_exports namespace
     * is implicitly available in the context of REFL_TYPE/FIELD/FUNC macros.
     * It is used to export the refl::attr:: standard attributes.
     */
    namespace detail
    {
        namespace macro_exports
        {
        }
    }

} // namespace refl

/**
 * refl_impl is an internal namespace that should not be used by the users of refl-cpp.
 */
namespace refl_impl
{
    /**
     * Contains the generated metadata types.
     * (i.e. type_info__)
     */
    namespace metadata
    {
        // Import everyting from macro_exports here to make it visible in REFL_ macro context.
        using namespace refl::detail::macro_exports;

        /**
         * The core reflection metadata type.
         * type_info__ holds data for a type T.
         *
         * The non-specialized type_info__ type has a member typedef invalid_marker
         * that can be used to detect it.
         *
         * Specializations of this type should provide all members of this
         * generic definition, except invalid_marker.
         *
         * @typeparam <T> The reflected type.
         */
        template <typename T>
        struct type_info__
        {
            /** Used for detecting this non-specialized type_info__ instance. */
            struct invalid_marker{};

            /**
             * This is a placeholder definition of which no type instances should be created.
             */
            template <size_t, typename>
            struct member;

            /** The number of reflected members of the target type T. */
            static constexpr size_t member_count{ 0 };

            /** This is a placeholder definition which shold not be referenced by well-formed programs. */
            static constexpr refl::const_string<0> name{ "" };

            /** This is a placeholder definition which shold not be referenced by well-formed programs. */
            static constexpr std::tuple<> attributes{ };
        };

        /**
         * Specializes type_info__ so that a type's const-qualification is effectively discarded.
         */
        template <typename T>
        struct type_info__<const T> : public type_info__<T> {};

        /**
         * Specializes type_info__ so that a type's volatile-qualification is effectively discarded.
         */
        template <typename T>
        struct type_info__<volatile T> : public type_info__<T> {};

        /**
         * Specializes type_info__ so that a type's const-volatile-qualification is effectively discarded.
         */
        template <typename T>
        struct type_info__<const volatile T> : public type_info__<T> {};

    } // namespace metadata

} // namespace refl_impl

namespace refl
{
    namespace detail
    {
        template <typename T>
        using type_info = refl_impl::metadata::type_info__<T>;

        template <typename T, size_t N>
        using member_info = typename type_info<T>::template member<N>;
    } // namespace detail

    /**
     * @brief Contains tag types denoting the different types of reflectable members.
     *
     * This namespace contains a number of empty types that correspond to
     * the different member types that refl-cpp supports reflection over.
     */
    namespace member
    {
        /**
         * An empty type which is equivalent to refl::member_descriptor_base::member_type
         * when the reflected member is a field.
         *
         * @see refl::descriptor::field_descriptor
         */
        struct field {};

        /**
         * An empty type which is equivalent to refl::member_descriptor_base::member_type
         * when the reflected member is a function.
         *
         * @see refl::descriptor::function_descriptor
         */
        struct function {};
    }

    namespace descriptor
    {
        template <typename>
        class type_descriptor;

        template <typename, size_t>
        class field_descriptor;

        template <typename, size_t>
        class function_descriptor;
    } // namespace descriptor

    /**
     * @brief Provides type-level operations for refl-cpp related use-cases.
     *
     * The refl::trait namespace provides type-level operations useful
     * for compile-time metaprogramming.
     */
    namespace trait
    {/**
         * Removes all reference and cv-qualifiers from T.
         * Equivalent to std::remove_cvref which is not currently
         * available on all C++17 compilers.
         */
        template <typename T>
        struct remove_qualifiers
        {
            typedef std::remove_cv_t<std::remove_reference_t<T>> type;
        };

        /**
         * Removes all reference and cv-qualifiers from T.
         * Equivalent to std::remove_cvref_t which is not currently
         * available on all C++17 compilers.
         */
        template <typename T>
        using remove_qualifiers_t = typename remove_qualifiers<T>::type;

        namespace detail
        {
            /** SFIANE support for detecting whether there is a type_info__ specialization for T. */
            template <typename T>
            decltype(typename refl::detail::type_info<T>::invalid_marker{}, std::false_type{}) is_reflectable_test(int);

            /** SFIANE support for detecting whether there is a type_info__ specialization for T. */
            template <typename T>
            std::true_type is_reflectable_test(...);
        } // namespace detail

        /**
         * Checks whether there is reflection metadata for the type T.
         * Inherits from std::bool_constant<>
         *
         * @see REFL_TYPE
         * @see REFL_AUTO
         * @see refl::is_reflectable
         */
        template <typename T>
        struct is_reflectable : decltype(detail::is_reflectable_test<T>(0))
        {
        };

        /**
         * Checks whether there is reflection metadata for the type T.
         * Inherits from std::bool_constant<>
         *
         * @see refl::trait::is_reflectable
         */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_reflectable_v{ is_reflectable<T>::value };

        namespace detail
        {
            /** SFIANE support for detecting whether the type T supports member .begin() and .end() operations. */
            template <typename U>
            [[maybe_unused]] static auto is_container_test(int) -> decltype(std::declval<U>().begin(), std::declval<U>().end(), std::true_type{});

            /** SFIANE support for detecting whether the type T supports member .begin() and .end() operations. */
            template <typename U>
            [[maybe_unused]] static std::false_type is_container_test(...);
        }

        /**
         * Checks whether objects of the type T support member .begin() and .end() operations.
         */
        template <typename T>
        struct is_container : decltype(detail::is_container_test<T>(0))
        {
        };

        /**
         * Checks whether objects of the type T support member .begin() and .end() operations.
         */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_container_v{ is_container<T>::value };

        namespace detail
        {

            template <size_t D, size_t N, typename... Ts>
            struct get;

            template <size_t D, size_t N>
            struct get<D, N>
            {
                static_assert(N > 0, "Missing arguments list for get<N, Ts...>!");
            };

            template <size_t N, typename T, typename... Ts>
            struct get<1, N, T, Ts...> : public get<
                                             (N > 16 ? (N > 64 ? 64 : 16) : 1),
                                             N - 1, Ts...>
            {
            };

            template <typename T, typename... Ts>
            struct get<1, 0, T, Ts...>
            {
                typedef T type;
            };

            template <typename T, typename... Ts>
            struct get<16, 0, T, Ts...>
            {
                typedef T type;
            };

            template <typename T, typename... Ts>
            struct get<64, 0, T, Ts...>
            {
                typedef T type;
            };

            template <
                size_t N, typename T0, typename T1, typename T2, typename T3,
                typename T4, typename T5, typename T6, typename T7, typename T8,
                typename T9, typename T10, typename T11, typename T12,
                typename T13, typename T14, typename T15, typename... Ts>
            struct get<
                16, N, T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
                T13, T14, T15, Ts...> : get<1, N - 16, Ts...>
            {
            };

            template <
                size_t N, typename T0, typename T1, typename T2, typename T3,
                typename T4, typename T5, typename T6, typename T7, typename T8,
                typename T9, typename T10, typename T11, typename T12,
                typename T13, typename T14, typename T15, typename T16,
                typename T17, typename T18, typename T19, typename T20,
                typename T21, typename T22, typename T23, typename T24,
                typename T25, typename T26, typename T27, typename T28,
                typename T29, typename T30, typename T31, typename T32,
                typename T33, typename T34, typename T35, typename T36,
                typename T37, typename T38, typename T39, typename T40,
                typename T41, typename T42, typename T43, typename T44,
                typename T45, typename T46, typename T47, typename T48,
                typename T49, typename T50, typename T51, typename T52,
                typename T53, typename T54, typename T55, typename T56,
                typename T57, typename T58, typename T59, typename T60,
                typename T61, typename T62, typename T63, typename... Ts>
            struct get<
                64, N, T0, T1, T2, T3, T4, T5, T6, T7, T8, T9, T10, T11, T12,
                T13, T14, T15, T16, T17, T18, T19, T20, T21, T22, T23, T24, T25,
                T26, T27, T28, T29, T30, T31, T32, T33, T34, T35, T36, T37, T38,
                T39, T40, T41, T42, T43, T44, T45, T46, T47, T48, T49, T50, T51,
                T52, T53, T54, T55, T56, T57, T58, T59, T60, T61, T62, T63,
                Ts...> : get<1, N - 64, Ts...>
            {
            };

            template <size_t N, typename...>
            struct skip;

            template <size_t N, typename T, typename... Ts>
            struct skip<N, T, Ts...> : skip<N - 1, Ts...>
            {
            };

            template <typename T, typename... Ts>
            struct skip<0, T, Ts...>
            {
                typedef type_list<T, Ts...> type;
            };

            template <>
            struct skip<0>
            {
                typedef type_list<> type;
            };
        }

        /// \private
        template <size_t, typename>
        struct get;

        /**
         * Provides a member typedef type which is the
         * N-th type in the provided type_list.
         *
         * \code{.cpp}
         * typename get<0, type_list<int, float>>::type -> int
         * typename get<1, type_list<int, float>>::type -> float
         * \endcode
         */
        template <size_t N, typename... Ts>
        struct get<N, type_list<Ts...>> : detail::get<1, N, Ts...>
        {
        };

        /**
         * The N-th type in the provided type_list.
         * @see get
         */
        template <size_t N, typename TypeList>
        using get_t = typename get<N, TypeList>::type;

        /// \private
        template <size_t, typename>
        struct skip;

        /**
         * Skips the first N types in the provided type_list.
         * Provides a member typedef equivalent to the resuling type_list.
         *
         * \code{.cpp}
         * typename skip<1, type_list<int, float, double>>::type -> type_list<float, double>
         * typename skip<0, type_list<int, float, double>>::type -> type_list<int, float, double>
         * \endcode
         */
        template <size_t N, typename... Ts>
        struct skip<N, type_list<Ts...>> : detail::skip<N, Ts...>
        {
        };

        /**
         * Skips the first N types in the provided type_list.
         * @see skip
         */
        template <size_t N, typename TypeList>
        using skip_t = typename skip<N, TypeList>::type;

        /// \private
        template <typename>
        struct as_type_list;

        /**
         * Provides a member typedef type which is a type_list with
         * template type parameters equivalent to the type parameters of the provided
         * type. The provided type must be a template instance.
         *
         * \code{.cpp}
         * typename as_type_list<std::tuple<int, float>>::type -> type_list<int, float>
         * \endcode
         */
        template <template <typename...> typename T, typename... Ts>
        struct as_type_list<T<Ts...>>
        {
            typedef type_list<Ts...> type;
        };

        /// \private
        template <typename T>
        struct as_type_list : as_type_list<remove_qualifiers_t<T>>
        {
        };

        /**
         * A typedef for a type_list with
         * template type parameters equivalent to the type parameters of the provided
         * type. The provided type must be a template instance.
         * @see as_type_list
         */
        template <typename T>
        using as_type_list_t = typename as_type_list<T>::type;

        /// \private
        template <typename>
        struct as_tuple;

        /**
         * Provides a member typedef which is a std::tuple specialization with
         * template type parameters equivalent to the type parameters of the provided
         * type. The provided type must be a template specialization.
         *
         * \code{.cpp}
         * typename as_tuple<type_list<int, float>>::type -> std::tuple<int, float>
         * \endcode
         */
        template <template <typename...> typename T, typename... Ts>
        struct as_tuple<T<Ts...>>
        {
            typedef std::tuple<Ts...> type;
        };

        /// \private
        template <typename T>
        struct as_tuple : as_tuple<remove_qualifiers_t<T>>
        {
        };

        /**
         * A typedef for a std::tuple specialization with
         * template type parameters equivalent to the type parameters of the provided
         * type. The provided type must be a template specialization.
         * @see as_tuple
         */
        template <typename T>
        using as_tuple_t = typename as_tuple<T>::type;

        /**
         * Accesses first type in the list.
         */
        template <typename TypeList>
        using first = get<0, TypeList>;

        /**
         * Accesses last type in the list.
         * @see last
         */
        template <typename TypeList>
        using first_t = typename first<TypeList>::type;

        /**
         * Accesses last type in the list.
         */
        template <typename TypeList>
        using last = get<TypeList::size - 1, TypeList>;

        /**
         * Accesses last type in the list.
         * @see last
         */
        template <typename TypeList>
        using last_t = typename last<TypeList>::type;

        /**
         * Returns all but the first element of the list.
         */
        template <typename TypeList>
        using tail = skip<1, TypeList>;

        /**
         * Returns all but the first element of the list.
         * @see tail
         */
        template <typename TypeList>
        using tail_t = typename tail<TypeList>::type;

        namespace detail
        {
            template <typename, size_t, typename>
            struct take;

            template <typename... Us>
            struct take<type_list<Us...>, 0, type_list<>>
            {
                using type = type_list<Us...>;
            };

            template <typename... Us, typename T, typename... Ts>
            struct take<type_list<Us...>, 0, type_list<T, Ts...>>
            {
                using type = type_list<Us...>;
            };

            template <size_t N, typename... Us, typename T, typename... Ts>
            struct take<type_list<Us...>, N, type_list<T, Ts...>>
            {
                using type = typename take<type_list<Us..., T>, N - 1, type_list<Ts...>>::type;
            };
        }

        /**
         * Returns the first N elements of the list.
         */
        template <size_t N, typename TypeList>
        using take = detail::take<type_list<>, N, TypeList>;

        /**
         * Returns the first N elements of the list.
         */
        template <size_t N, typename TypeList>
        using take_t = typename take<N, TypeList>::type;

        /**
         * Returns all but the last element of the list.
         */
        template <typename TypeList>
        using init = take<TypeList::size - 1, TypeList>;

        /**
         * Returns all but the last element of the list.
         * @see tail
         */
        template <typename TypeList>
        using init_t = typename init<TypeList>::type;

        namespace detail
        {
            template <typename, typename>
            struct reverse_impl;

            template <typename... Us>
            struct reverse_impl<type_list<Us...>, type_list<>>
            {
                using type = type_list<Us...>;
            };

            template <typename... Us, typename T, typename... Ts>
            struct reverse_impl<type_list<Us...>, type_list<T, Ts...>>
            {
                using type = typename reverse_impl<type_list<T, Us...>, type_list<Ts...>>::type;
            };
        } // namespace detail

        /**
         * Reverses a list of types.
         *
         * \code{.cpp}
         * typename reverse<type_list<int, float>>::type -> type_list<float, int>
         * \endcode
         */
        template <typename TypeList>
        struct reverse : detail::reverse_impl<type_list<>, TypeList>
        {
        };

        /**
         * Reverses a list of types.
         * @see reverse
         */
        template <typename TypeList>
        using reverse_t = typename reverse<TypeList>::type;

        /**
         * Concatenates N lists together.
         *
         * \code{.cpp}
         * typename concat<type_list<int, float>, type_list<double>, type_list<long>>::type -> type_list<int, float, double, long>
         * \endcode
         */
        template <typename...>
        struct concat;

        /// \private
        template <>
        struct concat<>
        {
            using type = type_list<>;
        };

        /// \private
        template <typename... Ts>
        struct concat<type_list<Ts...>>
        {
            using type = type_list<Ts...>;
        };

        /**
         * Concatenates two lists together.
         */
        /// \private
        template <typename... Ts, typename... Us>
        struct concat<type_list<Ts...>, type_list<Us...>>
        {
            using type = type_list<Ts..., Us...>;
        };

        /**
         * Concatenates N lists together.
         */
        /// \private
        template <typename TypeList1, typename TypeList2, typename... TypeLists>
        struct concat<TypeList1, TypeList2, TypeLists...> : concat<typename concat<TypeList1, TypeList2>::type, TypeLists...>
        {
        };

        /**
         * Concatenates two lists together.
         * @see concat
         */
        template <typename... Ts>
        using concat_t = typename concat<Ts...>::type;

        /**
         * Appends a type to the list.
         */
        template <typename T, typename TypeList>
        struct append : concat<TypeList, type_list<T>>
        {
        };

        /**
         * Appends a type to the list.
         * @see prepend
         */
        template <typename T, typename TypeList>
        using append_t = typename append<T, TypeList>::type;

        template <typename, typename>
        struct prepend;

        /**
         * Prepends a type to the list.
         */
        template <typename T, typename TypeList>
        struct prepend : concat<type_list<T>, TypeList>
        {
        };

        /**
         * Prepends a type to the list.
         * @see prepend
         */
        template <typename T, typename TypeList>
        using prepend_t = typename prepend<T, TypeList>::type;

        namespace detail
        {
            template <template<typename> typename, typename...>
            struct filter_impl;

            template <template<typename> typename Predicate>
            struct filter_impl<Predicate>
            {
                using type = type_list<>;
            };

            template <template<typename> typename Predicate, typename Head, typename... Tail>
            struct filter_impl<Predicate, Head, Tail...>
            {
                using type = std::conditional_t<Predicate<Head>::value,
                    prepend_t<Head, typename filter_impl<Predicate, Tail...>::type>,
                    typename filter_impl<Predicate, Tail...>::type
                >;
            };

            template <template<typename> typename, typename...>
            struct map_impl;

            template <template<typename> typename Mapper>
            struct map_impl<Mapper>
            {
                using type = type_list<>;
            };

            template <template<typename> typename Mapper, typename Head, typename ...Tail>
            struct map_impl<Mapper, Head, Tail...>
            {
                using type = typename prepend<typename Mapper<Head>::type,
                    typename map_impl<Mapper, Tail...>::type>::type;
            };
        }

        /// \private
        template <template<typename> typename, typename>
        struct filter;

        /**
         * Filters a type_list according to a predicate template.
         *
         * \code{.cpp}
         * typename filter<std::is_reference, type_list<int, float&, double>>::type -> type_list<float&>
         * \endcode
         */
        template <template<typename> typename Predicate, typename... Ts>
        struct filter<Predicate, type_list<Ts...>>
        {
            using type = typename detail::filter_impl<Predicate, Ts...>::type;
        };

        /**
         * Filters a type_list according to a predicate template
         * with a static boolean member named "value" (e.g. std::is_trivial)
         * @see filter
         */
        template <template<typename> typename Predicate, typename TypeList>
        using filter_t = typename filter<Predicate, TypeList>::type;

        /// \private
        template <template<typename> typename, typename>
        struct map;

        /**
         * Transforms a type_list according to a predicate template.
         *
         * \code{.cpp}
         * typename map<std::add_reference, type_list<int, float&, double>>::type -> type_list<int&, float&, double&>
         * \endcode
         */
        template <template<typename> typename Mapper, typename... Ts>
        struct map<Mapper, type_list<Ts...>>
        {
            using type = typename detail::map_impl<Mapper, Ts...>::type;
        };

        /**
         * Transforms a type_list according to a predicate template
         * with a typedef named "type" (e.g. std::remove_reference)
         * @see map
         */
        template <template<typename> typename Mapper, typename... Ts>
        using map_t = typename map<Mapper, Ts...>::type;

        namespace detail
        {
            template <typename T>
            struct is_instance : public std::false_type {};

            template <template<typename...> typename T, typename... Args>
            struct is_instance<T<Args...>> : public std::true_type {};
        } // namespace detail

        /**
         * Detects whether T is a template specialization.
         * Inherits from std::bool_constant<>.
         *
         * \code{.cpp}
         * is_instance<type_list<>>::value -> true
         * is_instance<int>::value -> false
         * \endcode
         */
        template <typename T>
        struct is_instance : detail::is_instance<T>
        {
        };

        /**
         * Detects whether T is a template specialization.
         * @see is_instance
         */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_instance_v{ is_instance<T>::value };

        namespace detail
        {
            /**
             * Checks if T == U<Args...>.
             * If U<Args...> != T or is invalid the result is false.
             */
            template <typename T, template<typename...> typename U, typename... Args>
            struct is_same_template
            {
                template <template<typename...> typename V, typename = V<Args...>>
                static auto test(int) -> std::is_same<V<Args...>, T>;

                template <template<typename...> typename V>
                static std::false_type test(...);

                static constexpr bool value{decltype(test<U>(0))::value};
            };

            template <template<typename...> typename T, typename U>
            struct is_instance_of : public std::false_type {};

            template <template<typename...> typename T, template<typename...> typename U, typename... Args>
            struct is_instance_of<T, U<Args...>> : public is_same_template<U<Args...>, T, Args...>
            {
            };
        }

        /**
         * Detects whther the type U is a template specialization of T.
         * (e.g. is_instance_of<std::vector<>, std::vector<int>>)
         * Inherits from std::bool_constant<>.
         *
         * \code{.cpp}
         * is_instance_of<type_list, type_list<int>>::value -> true
         * is_instance_of<type_list, std::tuple<int>>::value -> false
         * \endcode
         */
        template <template<typename...>typename T, typename U>
        struct is_instance_of : detail::is_instance_of<T, std::remove_cv_t<U>>
        {
        };

        /**
         * Detects whther the type U is a template specialization of T.
         * @see is_instance_of_v
         */
        template <template<typename...>typename T, typename U>
        [[maybe_unused]] static constexpr bool is_instance_of_v{ is_instance_of<T, U>::value };

        /// \private
        template <typename, typename>
        struct contains;

        /**
         * Checks whether T is contained in the list of types.
         * Inherits from std::bool_constant<>.
         *
         * \code{.cpp}
         * contains<int, type_list<int, float>>::value -> true
         * contains<double, type_list<int, float>>::value -> false
         * \endcode
         */
        template <typename T, typename... Ts>
        struct contains<T, type_list<Ts...>> : std::disjunction<std::is_same<std::remove_cv_t<T>, std::remove_cv_t<Ts>>...>
        {
        };

        /**
         * Checks whether T is contained in the list of types.
         * @see contains
         */
        template <typename T, typename TypeList>
        [[maybe_unused]] static constexpr bool contains_v = contains<T, TypeList>::value;

        /// \private
        template <template<typename...> typename, typename>
        struct contains_instance;

        /**
         * Checks whether an instance of the template T is contained in the list of types.
         * Inherits from std::bool_constant<>.
         *
         * \code{.cpp}
         * contains_instance<std::tuple, type_list<int, float, std::tuple<short, double>>>::value -> true
         * contains_instance<std::vector, type_list<int, float, std::tuple<short, double>>>::value -> false
         * \endcode
         */
        template <template<typename...> typename T, typename... Ts>
        struct contains_instance<T, type_list<Ts...>> : std::disjunction<trait::is_instance_of<T, std::remove_cv_t<Ts>>...>
        {
        };

        /**
         * Checks whether an instance of the template T is contained in the list of types.
         * @see contains_instance
         */
        template <template<typename...> typename T, typename TypeList>
        [[maybe_unused]] static constexpr bool contains_instance_v = contains_instance<T, TypeList>::value;

        /// \private
        template <typename, typename>
        struct contains_base;

        /**
         * Checks whether a type deriving from T is contained in the list of types.
         * Inherits from std::bool_constant<>.
         *
         * \code{.cpp}
         * struct Base {};
         * struct Derived : Base {};
         * contains_base<Base, type_list<int, float, Derived>>::value -> true
         * contains_base<Base, type_list<int, float, Base>>::value -> true
         * contains_base<int, type_list<int, float, Derived>>::value -> false
         * \endcode
         */
        template <typename T, typename... Ts>
        struct contains_base<T, type_list<Ts...>> : std::disjunction<std::is_base_of<std::remove_cv_t<T>, std::remove_cv_t<Ts>>...>
        {
        };

        /**
         * Checks whether a type deriving from T is contained in the list of types.
         * @see contains_base
         */
        template <typename T, typename TypeList>
        [[maybe_unused]] static constexpr bool contains_base_v = contains_base<T, TypeList>::value;

        namespace detail
        {
            template <typename T, ptrdiff_t N, typename... Ts>
            constexpr ptrdiff_t index_of() noexcept
            {
                if constexpr (sizeof...(Ts) <= N) return -1;
                else if constexpr (std::is_same_v<T, trait::get_t<N, type_list<Ts...>>>) return N;
                else return index_of<T, N + 1, Ts...>();
            }

            template <typename T, ptrdiff_t N, typename... Ts>
            constexpr ptrdiff_t index_of_base() noexcept
            {
                if constexpr (sizeof...(Ts) <= N) return -1;
                else if constexpr (std::is_base_of_v<T, trait::get_t<N, type_list<Ts...>>>) return N;
                else return index_of_base<T, N + 1, Ts...>();
            }

            template <template<typename...> typename T, ptrdiff_t N, typename... Ts>
            constexpr ptrdiff_t index_of_instance() noexcept
            {
                if constexpr (sizeof...(Ts) <= N) return -1;
                else if constexpr (is_instance_of_v<T, trait::get_t<N, type_list<Ts...>>>) return N;
                else return index_of_instance<T, N + 1, Ts...>();
            }

            // This variable template was introduced to fix the build on VS2017, which
            // chokes when invoking index_of_instance() directly from struct index_of_instance.
            template <template<typename...> typename T, ptrdiff_t N, typename... Ts>
            static constexpr ptrdiff_t index_of_instance_v = index_of_instance<T, N, Ts...>();
        } // namespace detail

        /// \private
        template <typename, typename>
        struct index_of;

        /**
         * The index of the type in the type list, -1 if it doesn't exist.
         * @see contains
         */
        template <typename T, typename... Ts>
        struct index_of<T, type_list<Ts...>> : std::integral_constant<ptrdiff_t, detail::index_of<T, 0, Ts...>()>
        {
        };

        /**
         * The index of the type in the type list, -1 if it doesn't exist.
         * @see index_of
         */
        template <typename T, typename TypeList>
        static constexpr ptrdiff_t index_of_v = index_of<T, TypeList>::value;

        /// \private
        template <typename, typename>
        struct index_of_base;

        /**
         * The index of the type in the type list that is derived from T, -1 if it doesn't exist.
         * @see contains_base
         */
        template <typename T, typename... Ts>
        struct index_of_base<T, type_list<Ts...>> : std::integral_constant<ptrdiff_t, detail::index_of_base<T, 0, Ts...>()>
        {
        };

        /**
         * The index of the type in the type list that is derived from T, -1 if it doesn't exist.
         * @see index_of_base
         */
        template <typename T, typename TypeList>
        static constexpr ptrdiff_t index_of_base_v = index_of_base<T, TypeList>::value;

        /// \private
        template <template<typename...> typename, typename>
        struct index_of_instance;

        /**
         * The index of the type in the type list that is a template instance of T, -1 if it doesn't exist.
         * @see contains_instance
         */
        template <template<typename...> typename T, typename... Ts>
        struct index_of_instance<T, type_list<Ts...>> : std::integral_constant<ptrdiff_t, detail::index_of_instance_v<T, 0, Ts...>>
        {
        };

        /**
         * The index of the type in the type list that is a template instance of T, -1 if it doesn't exist.
         * @see index_of_instance
         */
        template <template<typename...> typename T, typename TypeList>
        static constexpr ptrdiff_t index_of_instance_v = index_of_instance<T, TypeList>::value;

        namespace detail
        {
            template <typename, typename>
            struct unique_impl;

            template <typename UniqueList>
            struct unique_impl<UniqueList, type_list<>>
            {
                using type = UniqueList;
            };

            template <typename UniqueList, typename T, typename... Ts>
            struct unique_impl<UniqueList, type_list<T, Ts...>> :
                std::conditional_t<contains_v<T, UniqueList>,
                    unique_impl<UniqueList, type_list<Ts...>>,
                    unique_impl<append_t<T, UniqueList>, type_list<Ts...>>>
            {
            };
        } // namespace detail

        /**
         * Creates a new list containing the repeating elements in the source list only once.
         *
         * \code{.cpp}
         * typename unique<type_list<int, float, int>>::type -> type_list<int, float>
         * \endcode
         */
        template <typename T>
        struct unique : detail::unique_impl<type_list<>, T>
        {
        };

        /**
         * Creates a new list containing the repeating elements in the source list only once.
         */
        template <typename T>
        using unique_t = typename unique<T>::type;

    } // namespace trait

    namespace util
    {
        /**
         * Ignores all parameters. Can take an optional template parameter
         * specifying the return type of ignore. The return object is iniailized by {}.
         */
        template <typename T = int, typename... Ts>
        constexpr int ignore(Ts&&...) noexcept
        {
            return {};
        }

        /**
         * Returns the input paratemeter as-is. Useful for expanding variadic
         * template lists when only one arguments is known to be present.
         */
        template <typename T>
        constexpr decltype(auto) identity(T&& t) noexcept
        {
            return std::forward<T>(t);
        }

        /**
         * Adds const to the input reference.
         */
        template <typename T>
        constexpr const T& make_const(const T& value) noexcept
        {
            return value;
        }

        /**
         * Adds const to the input reference.
         */
        template <typename T>
        constexpr const T& make_const(T& value) noexcept
        {
            return value;
        }

        /**
        * Creates an array of type 'T' from the provided tuple.
        * The common type T needs to be specified, in order to prevent any
        * errors when using the overload taking an empty std::tuple (as there is no common type then).
        */
        template <typename T, typename... Ts>
        constexpr std::array<T, sizeof...(Ts)> to_array(const std::tuple<Ts...>& tuple) noexcept
        {
            return std::apply([](auto&& ... args) -> std::array<T, sizeof...(Ts)> { return { std::forward<decltype(args)>(args)... }; }, tuple);
        }

        /**
         * Creates an empty array of type 'T.
         */
        /// \private
        template <typename T>
        constexpr std::array<T, 0> to_array(const std::tuple<>&) noexcept
        {
            return {};
        }

        namespace detail
        {
            template <typename T, size_t... Idx>
            constexpr auto to_tuple([[maybe_unused]] const std::array<T, sizeof...(Idx)>& array, std::index_sequence<Idx...>) noexcept
            {
                if constexpr (sizeof...(Idx) == 0) return std::tuple<>{};
                else return std::make_tuple(std::get<Idx>(array)...);
            }
        }

        /**
         * Creates a tuple from the provided array.
         */
        template <typename T, size_t N>
        constexpr auto to_tuple(const std::array<T, N>& array) noexcept
        {
            return detail::to_tuple<T>(array, std::make_index_sequence<N>{});
        }

        /**
         * Creates a matching std::tuple from a type_list.
         * Types in the type_list must be Trivial.
         */
        template <typename... Ts>
        constexpr std::tuple<Ts...> as_tuple(type_list<Ts...>) noexcept
        {
            static_assert((... && std::is_trivial_v<Ts>), "Non-trivial types in type_list as not allowed!");
            return {};
        }

        /**
         * Creates a matching type_list from a std::tuple.
         */
        template <typename... Ts>
        constexpr type_list<Ts...> as_type_list(const std::tuple<Ts...>&) noexcept
        {
            return {};
        }

        namespace detail
        {
            template <typename F, typename T>
            constexpr auto invoke_optional_index(F&& f, T&& t, size_t idx, int) -> decltype(f(std::forward<T>(t), idx))
            {
                return f(std::forward<T>(t), idx);
            }

            template <typename F, typename T>
            constexpr auto invoke_optional_index(F&& f, T&& t, size_t, ...) -> decltype(f(std::forward<T>(t)))
            {
                return f(std::forward<T>(t));
            }

            template <typename F, typename... Carry>
            constexpr auto eval_in_order_to_tuple(type_list<>, std::index_sequence<>, F&&, Carry&&... carry)
            {
                if constexpr (sizeof...(Carry) == 0) return std::tuple<>{};
                else return std::make_tuple(std::forward<Carry>(carry)...);
            }

            // This workaround is needed since C++ does not specify
            // the order in which function arguments are evaluated and this leads
            // to incorrect order of evaluation (noticeable when using indexes).
            // Otherwise we could simply do std::make_tuple(f(Ts{}, Idx)...).
            template <typename F, typename T, typename... Ts, size_t I, size_t... Idx, typename... Carry>
            constexpr auto eval_in_order_to_tuple(type_list<T, Ts...>, std::index_sequence<I, Idx...>, F&& f, Carry&&... carry)
            {
                static_assert(std::is_trivial_v<T>, "Argument is a non-trivial type!");

                auto&& result = invoke_optional_index(f, T{}, I, 0);
                return eval_in_order_to_tuple(
                    type_list<Ts...>{},
                    std::index_sequence<Idx...>{},
                    std::forward<F>(f),
                    std::forward<Carry>(carry)..., // carry the previous results over
                    std::forward<decltype(result)>(result) // pass the current result after them
                );
            }

            template <typename F>
            constexpr void eval_in_order(type_list<>, std::index_sequence<>, [[maybe_unused]]F&& f)
            {
            }

            // This workaround is needed since C++ does not specify
            // the order in which function arguments are evaluated and this leads
            // to incorrect order of evaluation (noticeable when using indexes).
            template <typename F, typename T, typename... Ts, size_t I, size_t... Idx>
            constexpr void eval_in_order(type_list<T, Ts...>, std::index_sequence<I, Idx...>, F&& f)
            {
                static_assert(std::is_trivial_v<T>, "Argument is a non-trivial type!");

                invoke_optional_index(f, T{}, I, 0);
                return eval_in_order(
                    type_list<Ts...>{},
                    std::index_sequence<Idx...>{},
                    std::forward<F>(f)
                );
            }
        }

        /**
         * Applies function F to each type in the type_list, aggregating
         * the results in a tuple. F can optionally take an index of type size_t.
         *
         * \code{.cpp}
         * map_to_tuple(reflect_types(type_list<int, float, double>{}), [](auto td) {
         *   return get_name(td);
         * })
         *   -> std::tuple{const_string{"int"}, const_string{"float"}, const_string{"double"}}
         * \endcode
         */
        template <typename F, typename... Ts>
        constexpr auto map_to_tuple(type_list<Ts...> list, F&& f)
        {
            return detail::eval_in_order_to_tuple(list, std::make_index_sequence<sizeof...(Ts)>{}, std::forward<F>(f));
        }

        /**
         * Applies function F to each type in the type_list, aggregating
         * the results in an array. F can optionally take an index of type size_t.
         *
         * \code{.cpp}
         * map_to_array<std::string>(reflect_types(type_list<int, float, double>{}), [](auto td) {
         *   return get_name(td).str();
         * })
         *   -> std::array{std::string{"int"}, std::string{"float"}, std::string{"double"}}
         * \endcode
         */
        template <typename T, typename F, typename... Ts>
        constexpr auto map_to_array(type_list<Ts...> list, F&& f)
        {
            return to_array<T>(map_to_tuple(list, std::forward<F>(f)));
        }

        /**
         * Applies function F to each type in the type_list.
         * F can optionally take an index of type size_t.
         *
         * \code{.cpp}
         * for_each(reflect_types(type_list<int, float, double>{}), [](auto td) {
         *   std::cout << get_name(td) << '\n';
         * });
         * \endcode
         */
        template <typename F, typename... Ts>
        constexpr void for_each(type_list<Ts...> list, F&& f)
        {
            detail::eval_in_order(list, std::make_index_sequence<sizeof...(Ts)>{}, std::forward<F>(f));
        }

        /*
         * Returns the initial_value unchanged.
         */
        /// \private
        template <typename R, typename F, typename... Ts>
        constexpr R accumulate(type_list<>, F&&, R&& initial_value)
        {
            return std::forward<R>(initial_value);
        }

        /*
        * Applies an accumulation function F to each type in the type_list.
        * Note: Breaking changes introduced in v0.7.0:
        *   Behaviour changed to imitate std::accumulate.
        *   F can now no longer take a second index argument.
        */
        template <typename R, typename F, typename T, typename... Ts>
        constexpr auto accumulate(type_list<T, Ts...>, F&& f, R&& initial_value)
        {
            static_assert(std::is_trivial_v<T>, "Argument is a non-trivial type!");

            return accumulate(type_list<Ts...> {},
                std::forward<F>(f),
                std::forward<std::invoke_result_t<F&&, R&&, T&&>>(
                    f(std::forward<R>(initial_value), T {})));
        }

        /**
         * Counts the number of times the predicate F returns true.
        * Note: Breaking changes introduced in v0.7.0:
        *   F can now no longer take a second index argument.
         */
        template <typename F, typename... Ts>
        constexpr size_t count_if(type_list<Ts...> list, F&& f)
        {
            return accumulate<size_t>(list,
                [&](size_t acc, const auto& t) -> size_t { return acc + (f(t) ? 1 : 0); },
                0);
        }

        namespace detail
        {
            template <typename, bool...>
            struct apply_mask;

            template <>
            struct apply_mask<type_list<>>
            {
                using type = type_list<>;
            };

            template <typename T, typename... Ts, bool... Bs>
            struct apply_mask<type_list<T, Ts...>, true, Bs...>
            {
                static_assert(std::is_trivial_v<T>, "Argument is a non-trivial type!");
                using type = trait::prepend_t<T, typename apply_mask<type_list<Ts...>, Bs...>::type>;
            };

            template <typename T, typename... Ts, bool... Bs>
            struct apply_mask<type_list<T, Ts...>, false, Bs...> : apply_mask<type_list<Ts...>, Bs...>
            {
                static_assert(std::is_trivial_v<T>, "Argument is a non-trivial type!");
            };

            template <typename F, typename... Ts>
            constexpr auto filter([[maybe_unused]] F f, type_list<Ts...>)
            {
                return typename apply_mask<type_list<Ts...>, f(Ts{})...>::type{};
            }
        }

        /**
         * Filters the list according to a *constexpr* predicate.
         * Calling f(Ts{})... should be valid in a constexpr context.
         *
         * \code{.cpp}
         * filter(reflect_types(type_list<int, long, float>{}), [](auto td) {
         *   return std::is_integral_v<typename decltype(td)::type>;
         * })
         *   -> type_list<type_descriptor<int>, type_descriptor<long>>
         * \endcode
         */
        template <typename F, typename... Ts>
        constexpr auto filter(type_list<Ts...> list, F&& f)
        {
            return decltype(detail::filter(std::forward<F>(f), list))();
        }

        /**
         * Returns the first instance that matches the *constexpr* predicate.
         * Calling f(Ts{})... should be valid in a constexpr context.
         */
        template <typename F, typename... Ts>
        constexpr auto find_first(type_list<Ts...> list, F&& f)
        {
            using result_list = decltype(detail::filter(std::forward<F>(f), list));
            static_assert(result_list::size != 0, "find_first did not match anything!");
            return trait::get_t<0, result_list>{};
        }

        /**
         * Returns the only instance that matches the *constexpr* predicate.
         * If there is no match or multiple matches, fails with static_assert.
         * Calling f(Ts{})... should be valid in a constexpr context.
         */
        template <typename F, typename... Ts>
        constexpr auto find_one(type_list<Ts...> list, F&& f)
        {
            using result_list = decltype(detail::filter(std::forward<F>(f), list));
            static_assert(result_list::size != 0, "find_one did not match anything!");
            static_assert(result_list::size == 1, "Cannot resolve multiple matches in find_one!");
            return trait::get_t<0, result_list>{};
        }

        /**
         * Returns true if any item in the list matches the predicate.
         * Calling f(Ts{})... should be valid in a constexpr context.
         */
        template <typename F, typename... Ts>
        constexpr bool contains(type_list<Ts...> list, F&& f)
        {
            using result_list = decltype(detail::filter(std::forward<F>(f), list));
            return result_list::size > 0;
        }

        /**
         * Returns true if the type_list contains the specified type.
         * @see refl::trait::contains
         */
        template <typename T, typename... Ts>
        constexpr bool contains(type_list<Ts...>)
        {
            return trait::contains_v<T, type_list<Ts...>>;
        }

        /**
         * Returns true if the tuple contains the specified type or a supertype.
         * @see refl::trait::contains_base
         */
        template <typename T, typename... Ts>
        constexpr bool contains_base(const std::tuple<Ts...>&)
        {
            return trait::contains_base_v<T, type_list<Ts...>>;
        }

        /**
         * Returns true if the tuple contains an instance of the specified type.
         * @see refl::trait::contains_instance
         */
        template <template <typename...> typename T, typename... Ts>
        constexpr bool contains_instance(const std::tuple<Ts...>&)
        {
            return trait::contains_instance_v<T, type_list<Ts...>>;
        }

        /**
         * Applies a function to the elements of the type_list.
         *
         * \code{.cpp}
         * apply(reflect_types(type_list<int, long, float>{}), [](auto td_int, auto td_long, auto td_float) {
         *   return get_name(td_int) + " " +get_name(td_long) + " " + get_name(td_float);
         * })
         *   -> "int long float"
         * \endcode
         */
        template <typename... Ts, typename F>
        constexpr auto apply(type_list<Ts...>, F&& f)
        {
            return f(Ts{}...);
        }

        /** A synonym for std::get<N>(tuple). */
        template <size_t N, typename... Ts>
        constexpr auto& get(std::tuple<Ts...>& ts) noexcept
        {
            return std::get<N>(ts);
        }

        /** A synonym for std::get<N>(tuple). */
        template <size_t N, typename... Ts>
        constexpr const auto& get(const std::tuple<Ts...>& ts) noexcept
        {
            return std::get<N>(ts);
        }

        /** A synonym for std::get<T>(tuple). */
        template <typename T, typename... Ts>
        constexpr T& get(std::tuple<Ts...>& ts) noexcept
        {
            return std::get<T>(ts);
        }

        /** A synonym for std::get<T>(tuple). */
        template <typename T, typename... Ts>
        constexpr const T& get(const std::tuple<Ts...>& ts) noexcept
        {
            return std::get<T>(ts);
        }

        /** Returns the value of type U, where U is a template instance of T. */
        template <template<typename...> typename T, typename... Ts>
        constexpr auto& get_instance(std::tuple<Ts...>& ts) noexcept
        {
            static_assert((... || trait::is_instance_of_v<T, Ts>), "The tuple does not contain a type that is a template instance of T!");
            constexpr size_t idx = static_cast<size_t>(trait::index_of_instance_v<T, type_list<Ts...>>);
            return std::get<idx>(ts);
        }

        /** Returns the value of type U, where U is a template instance of T. */
        template <template<typename...> typename T, typename... Ts>
        constexpr const auto& get_instance(const std::tuple<Ts...>& ts) noexcept
        {
            static_assert((... || trait::is_instance_of_v<T, Ts>), "The tuple does not contain a type that is a template instance of T!");
            constexpr size_t idx = static_cast<size_t>(trait::index_of_instance_v<T, type_list<Ts...>>);
            return std::get<idx>(ts);
        }

        /**
         * Converts a type_list of types to a type_list of the type_descriptors for these types.
         *
         * \code{.cpp}
         * reflect_types(type_list<int, float>{}) -> type_list<type_descriptor<int>, type_descriptor<float>>{}
         * \endcode
         */
        template <typename... Ts>
        constexpr type_list<descriptor::type_descriptor<Ts>...> reflect_types(type_list<Ts...>) noexcept
        {
            return {};
        }

        /**
         * Converts a type_list of type_descriptors to a type_list of the target types.
         *
         * \code{.cpp}
         * unreflect_types(type_list<type_descriptor<int>, type_descriptor<float>>{}) -> type_list<int, float>{}
         * \endcode
         */
        template <typename... Ts>
        constexpr type_list<Ts...> unreflect_types(type_list<descriptor::type_descriptor<Ts>...>) noexcept
        {
            return {};
        }
    } // namespace util

    /**
     * @brief Contains the definitions of the built-in attributes
     *
     * Contains the definitions of the built-in attributes which
     * are implicitly available in macro context as well as the
     * attr::usage namespace which contains constraints
     * for user-provieded attributes.
     *
     * # Examples
     * ```
     * REFL_TYPE(Point, debug(custom_printer))
     *     REFL_FIELD(x)
     *     REFL_FIELD(y)
     * REFL_END
     * ```
     */
    namespace attr
    {
        /**
         * @brief Contains a number of constraints applicable to refl-cpp attributes.
         *
         * Contains base types which create compile-time constraints
         * that are verified by refl-cpp. These base-types must be inherited
         * by custom attribute types.
         */
        namespace usage
        {
            /**
             * Specifies that an attribute type inheriting from this type can
             * only be used with REFL_TYPE()
             */
            struct type {};

            /**
             * Specifies that an attribute type inheriting from this type can
             * only be used with REFL_FUNC()
             */
            struct function {};

            /**
             * Specifies that an attribute type inheriting from this type can
             * only be used with REFL_FIELD()
             */
            struct field {};

            /**
             * Specifies that an attribute type inheriting from this type can
             * only be used with REFL_FUNC or REFL_FIELD.
             */
            struct member : public function, public field{};

            /**
             * Specifies that an attribute type inheriting from this type can
             * only be used with any one of REFL_TYPE, REFL_FIELD, REFL_FUNC.
             */
            struct any : public member, public type {};
        }

        /**
         * Used to decorate a function that serves as a property.
         * Takes an optional friendly name.
         */
        struct property : public usage::function
        {
            const std::optional<const char*> friendly_name;

            constexpr property() noexcept
                : friendly_name{}
            {
            }

            constexpr property(const char* friendly_name) noexcept
                : friendly_name(friendly_name)
            {
            }
        };

        /**
         * Used to specify how a type should be displayed in debugging contexts.
         */
        template <typename F>
        struct debug : public usage::any
        {
            const F write;

            constexpr debug(F write)
                : write(write)
            {
            }
        };

        /**
         * Used to specify the base types of the target type.
         */
        template <typename... Ts>
        struct base_types : usage::type
        {
            /** An alias for a type_list of the base types. */
            typedef type_list<Ts...> list_type;

            /** An instance of a type_list of the base types. */
            static constexpr list_type list{ };
        };

        /**
         * Used to specify the base types of the target type.
         */
        template <typename... Ts>
        [[maybe_unused]] static constexpr base_types<Ts...> bases{ };
    } // namespace attr


    namespace detail
    {
        namespace macro_exports
        {
            using attr::property;
            using attr::debug;
            using attr::bases;
        }
    }

    namespace trait
    {
        namespace detail
        {
            template <typename T>
            auto member_type_test(int) -> decltype(typename T::member_type{}, std::true_type{});

            template <typename T>
            std::false_type member_type_test(...);
        }

        /**
         * A trait for detecting whether the type 'T' is a member descriptor.
         */
        template <typename T>
        struct is_member : decltype(detail::member_type_test<T>(0))
        {
        };

        /**
         * A trait for detecting whether the type 'T' is a member descriptor.
         */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_member_v{ is_member<T>::value };

        namespace detail
        {
            template <typename T>
            struct is_field_2 : std::is_base_of<typename T::member_type, member::field>
            {
            };
        }

        /**
         * A trait for detecting whether the type 'T' is a field descriptor.
         */
        template <typename T>
        struct is_field : std::conjunction<is_member<T>, detail::is_field_2<T>>
        {
        };

        /**
         * A trait for detecting whether the type 'T' is a field descriptor.
         */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_field_v{ is_field<T>::value };

        namespace detail
        {
            template <typename T>
            struct is_function_2 : std::is_base_of<typename T::member_type, member::function>
            {
            };
        }

        /**
         * A trait for detecting whether the type 'T' is a function descriptor.
         */
        template <typename T>
        struct is_function : std::conjunction<is_member<T>, detail::is_function_2<T>>
        {
        };

        /**
         * A trait for detecting whether the type 'T' is a function descriptor.
         */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_function_v{ is_function<T>::value };

        /**
         * Detects whether the type T is a type_descriptor.
         * Inherits from std::bool_constant<>.
         */
        template <typename T>
        struct is_type : is_instance_of<descriptor::type_descriptor, T>
        {
        };

        /**
         * Detects whether the type T is a type_descriptor.
         * @see is_type
         */
        template <typename T>
        [[maybe_unused]] constexpr bool is_type_v{ is_type<T>::value };

        /**
         * A trait for detecting whether the type 'T' is a refl-cpp descriptor.
         */
        template <typename T>
        struct is_descriptor : std::disjunction<is_type<T>, is_member<T>>
        {
        };

        /**
         * A trait for detecting whether the type 'T' is a refl-cpp descriptor.
         */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_descriptor_v{ is_descriptor<T>::value };


        /** Checks whether T is marked as a property. */
        template <typename T>
        struct is_property : std::bool_constant<
            trait::is_function_v<T> && trait::contains_v<attr::property, typename T::attribute_types>>
        {
        };

        /** Checks whether T is marked as a property. */
        template <typename T>
        [[maybe_unused]] static constexpr bool is_property_v{ is_property<T>::value };
    } // namespace trait

    /**
     * @brief Contains the basic reflection primitives
     * as well as functions operating on those primitives
     */
    namespace descriptor
    {
        namespace detail
        {
            template <typename Member>
            struct static_field_invoker
            {
                static constexpr auto invoke() -> decltype(*Member::pointer)
                {
                    return *Member::pointer;
                }

                template <typename U, typename M = Member, std::enable_if_t<M::is_writable, int> = 0>
                static constexpr auto invoke(U&& value) -> decltype(*Member::pointer = std::forward<U>(value))
                {
                    return *Member::pointer = std::forward<U>(value);
                }
            };

            template <typename Member>
            struct instance_field_invoker
            {
                template <typename T>
                static constexpr auto invoke(T&& target) -> decltype(target.*(Member::pointer))
                {
                    return target.*(Member::pointer);
                }

                template <typename T, typename U, typename M = Member, std::enable_if_t<M::is_writable, int> = 0>
                static constexpr auto invoke(T&& target, U&& value) -> decltype(target.*(Member::pointer) = std::forward<U>(value))
                {
                    return target.*(Member::pointer) = std::forward<U>(value);
                }
            };

            template <typename Member>
            static_field_invoker<Member> field_type_switch(std::true_type);

            template <typename Member>
            instance_field_invoker<Member> field_type_switch(std::false_type);

            template <typename Member>
            constexpr decltype(nullptr) get_function_pointer(...)
            {
                return nullptr;
            }

            template <typename Member>
            constexpr auto get_function_pointer(int) -> decltype(Member::pointer())
            {
                return Member::pointer();
            }

            template <typename Member, typename Pointer>
            constexpr decltype(nullptr) resolve_function_pointer(...)
            {
                return nullptr;
            }

            template <typename Member, typename Pointer>
            constexpr auto resolve_function_pointer(int) -> decltype(Member::template resolve<Pointer>())
            {
                return Member::template resolve<Pointer>();
            }

            template <typename T, size_t N>
            using make_descriptor = std::conditional_t<refl::trait::is_field_v<refl::detail::member_info<T, N>>,
                field_descriptor<T, N>,
                std::conditional_t<refl::trait::is_function_v<refl::detail::member_info<T, N>>,
                    function_descriptor<T, N>,
                    void
                >>;

            template <typename T>
            type_list<> enumerate_members(std::index_sequence<>);

            template <typename T, size_t... Idx>
            type_list<make_descriptor<T, Idx>...> enumerate_members(std::index_sequence<Idx...>);

            template <typename T>
            struct declared_member_list
            {
                static_assert(refl::trait::is_reflectable_v<T>, "This type does not support reflection!");
                using type = decltype(enumerate_members<T>(std::make_index_sequence<refl::detail::type_info<T>::member_count>{}));
            };

            template <typename T>
            using attribute_types = trait::as_type_list_t<std::remove_cv_t<decltype(refl::detail::type_info<T>::attributes)>>;

            template <typename>
            struct flatten;

            template <typename... TypeLists>
            struct flatten<type_list<TypeLists...>> : trait::concat<TypeLists...>
            {
            };

            template <typename T, typename Base>
            static constexpr void validate_base()
            {
                static_assert(std::is_base_of_v<Base, T>, "Base is not a base type of T!");
            }

            template <typename T, typename... Bases>
            static constexpr void validate_bases(type_list<Bases...>)
            {
                util::ignore((validate_base<T, Bases>(), 0)...);
            }

            template <typename T>
            static constexpr auto get_declared_base_type_list()
            {
                if constexpr (trait::contains_instance_v<attr::base_types, attribute_types<T>>) {
                    using base_types_type = trait::remove_qualifiers_t<decltype(util::get_instance<attr::base_types>(refl::detail::type_info<T>::attributes))>;
                    validate_bases<T>(base_types_type::list);
                    return typename base_types_type::list_type{};
                }
                else {
                    return type_list<>{};
                }
            }

            template <typename T>
            struct declared_base_type_list
            {
                using type = decltype(get_declared_base_type_list<T>());
            };

            template <typename T>
            struct base_type_list;

            template <typename T>
            static constexpr auto get_base_type_list()
            {
                if constexpr (trait::contains_instance_v<attr::base_types, attribute_types<T>>) {
                    using declared_bases = typename declared_base_type_list<T>::type;
                    using rec_bases = typename flatten<trait::map_t<base_type_list, declared_bases>>::type;
                    return trait::unique_t<trait::concat_t<declared_bases, rec_bases>>{};
                }
                else {
                    return type_list<>{};
                }
            }

            template <typename T>
            struct base_type_list
            {
                using type = decltype(get_base_type_list<T>());
            };

            template <typename T>
            struct member_list : flatten<trait::map_t<declared_member_list, trait::prepend_t<T, typename base_type_list<T>::type>>>
            {
            };

        } // namespace detail

        /** A type_list of the declared member descriptors of the target type T. */
        template <typename T>
        using declared_member_list = typename detail::declared_member_list<T>::type;

        /** A type_list of the declared and inherited member descriptors of the target type T. */
        template <typename T>
        using member_list = typename detail::member_list<T>::type;

        /**
         * @brief The base type for member descriptors.
         */
        template <typename T, size_t N>
        class member_descriptor_base
        {
        protected:

            typedef refl::detail::member_info<T, N> member;

        public:

            /**
             * An alias for the declaring type of the reflected member.
             *
             * \code{.cpp}
             * struct Foo { const int* x; };
             * REFL_AUTO(type(Foo), field(x))
             *
             * get_t<0, member_list<Foo>>::declaring_type -> Foo
             * \endcode
             */
            typedef T declaring_type;

            /** An alias specifying the member type of member. */
            typedef typename member::member_type member_type;

            /**
             * An alias specifying the types of the attributes of the member. (Removes CV-qualifiers.)
             * \copydetails refl::descriptor::get_attribute_types
             */
            typedef trait::as_type_list_t<std::remove_cv_t<decltype(member::attributes)>> attribute_types;

            /**
             * The type_descriptor of the declaring type.
             * \copydetails refl::descriptor::get_declarator
             */
            static constexpr type_descriptor<T> declarator{ };

            /**
             * The name of the reflected member.
             * \copydetails refl::descriptor::get_name
             */
            static constexpr auto name{ member::name };

            /**
             * The attributes of the reflected member.
             * \copydetails refl::descriptor::get_attributes
             */
            static constexpr auto attributes{ member::attributes };

        };

        /**
         * @brief Represents a reflected field.
         */
        template <typename T, size_t N>
        class field_descriptor : public member_descriptor_base<T, N>
        {
            using typename member_descriptor_base<T, N>::member;
            static_assert(trait::is_field_v<member>);

        public:

            /**
             * Type value type of the member.
             *
             * \code{.cpp}
             * struct Foo { const int* x; };
             * REFL_AUTO(type(Foo), field(x))
             *
             * get_t<0, member_list<Foo>>::value_type -> const int*
             * \endcode
             */
            typedef typename member::value_type value_type;

            /**
             * Whether the field is static or not.
             * \copydetails refl::descriptor::is_static
             */
            static constexpr bool is_static{ !std::is_member_object_pointer_v<decltype(member::pointer)> };

            /**
             * Whether the field is const or not.
             * @see refl::descriptor::is_const
             */
            static constexpr bool is_writable{ !std::is_const_v<value_type> };

            /**
             * A member pointer to the reflected field of the appropriate type.
             * \copydetails refl::descriptor::get_pointer
             */
            static constexpr auto pointer{ member::pointer };

        private:

            using invoker = decltype(detail::field_type_switch<field_descriptor>(std::bool_constant<is_static>{}));

        public:

            /**
             * Returns the value of the field. (for static fields).
             * \copydetails refl::descriptor::invoke
             */
            template <decltype(nullptr) = nullptr>
            static constexpr decltype(auto) get() noexcept
            {
                return *member::pointer;
            }

            /**
             * Returns the value of the field. (for instance fields).
             * \copydetails refl::descriptor::invoke
             */
            template <typename U>
            static constexpr decltype(auto) get(U&& target) noexcept
            {
                return target.*(member::pointer);
            }

            /**
             * A synonym for get().
             * \copydetails refl::descriptor::invoke
             */
            template <typename... Args>
            constexpr auto operator()(Args&&... args) const noexcept -> decltype(invoker::invoke(std::forward<Args>(args)...))
            {
                return invoker::invoke(std::forward<Args>(args)...);
            }

        };

        /**
         * @brief Represents a reflected function.
         */
        template <typename T, size_t N>
        class function_descriptor : public member_descriptor_base<T, N>
        {
            using typename member_descriptor_base<T, N>::member;
            static_assert(trait::is_function_v<member>);

        public:

            /**
             * Invokes the function with the given arguments.
             * If the function is an instance function, a reference
             * to the instance is provided as first argument.
             * \copydetails refl::descriptor::invoke
             */
            template <typename... Args>
            static constexpr auto invoke(Args&&... args) -> decltype(member::invoke(std::declval<Args>()...))
            {
                return member::invoke(std::forward<Args>(args)...);
            }

            /**
             * The return type of an invocation of this member with Args... (as if by invoke(...)).
             * \copydetails refl::descriptor::return_type
             */
            template <typename... Args>
            using return_type = decltype(member::invoke(std::declval<Args>()...));

            /**
             * A synonym for invoke(args...).
             * \copydetails refl::descriptor::invoke
             */
            template <typename... Args>
            constexpr auto operator()(Args&&... args) const -> decltype(invoke(std::declval<Args>()...))
            {
                return invoke(std::forward<Args>(args)...);
            }

            /**
             * Returns a pointer to a non-overloaded function.
             * \copydetails refl::descriptor::get_pointer
             */
            static constexpr auto pointer{ detail::get_function_pointer<member>(0) };

            /**
             * Whether the pointer member was correctly resolved to a concrete implementation.
             * If this field is false, resolve() would need to be called instead.
             * \copydetails refl::descriptor::is_resolved
             */
            static constexpr bool is_resolved{ !std::is_same_v<decltype(pointer), const decltype(nullptr)> };

            /**
             * Whether the pointer can be resolved as with the specified type.
             * \copydetails refl::descriptor::can_resolve
             */
            template <typename Pointer>
            static constexpr bool can_resolve()
            {
                return !std::is_same_v<decltype(resolve<Pointer>()), decltype(nullptr)>;
            }

            /**
             * Resolves the function pointer as being of type Pointer.
             * Required when taking a pointer to an overloaded function.
             *
             * \copydetails refl::descriptor::resolve
             */
            template <typename Pointer>
            static constexpr auto resolve()
            {
                return detail::resolve_function_pointer<member, Pointer>(0);
            }

        };

        /** Represents a reflected type. */
        template <typename T>
        class type_descriptor
        {
        private:

            static_assert(refl::trait::is_reflectable_v<T>, "This type does not support reflection!");

            typedef refl::detail::type_info<T> type_info;

        public:

            /**
             * The reflected type T.
             *
             * \code{.cpp}
             * struct Foo {};
             * REFL_AUTO(type(Foo))
             *
             * type_descriptor<Foo>::type -> Foo
             * \endcode
             */
            typedef T type;

            /**
             * The declared base types (via base_types<Ts...> attribute) of T.
             * \copydetails refl::descriptor::get_declared_base_types
             */
            typedef typename detail::declared_base_type_list<T>::type declared_base_types;

            /**
             * The declared and inherited base types of T.
             * \copydetails refl::descriptor::get_base_types
             */
            typedef typename detail::base_type_list<T>::type base_types;

            /**
             * A synonym for declared_member_list<T>.
             * \copydetails refl::descriptor::declared_member_list
             */
            typedef declared_member_list<T> declared_member_types;

            /**
             * A synonym for member_list<T>.
             * \copydetails refl::descriptor::member_list
             */
            typedef member_list<T> member_types;

            /**
             * An alias specifying the types of the attributes of the member. (Removes CV-qualifiers.)
             * \copydetails refl::descriptor::get_attribute_types
             */
            typedef detail::attribute_types<T> attribute_types;

            /**
             * The declared base types (via base_types<Ts...> attribute) of T.
             * \copydetails refl::descriptor::get_declared_base_types
             */
            static constexpr declared_base_types declared_bases{};

            /**
             * The declared  and inherited base types of T.
             * \copydetails refl::descriptor::get_base_types
             */
            static constexpr base_types bases{};

            /**
             * The list of declared member descriptors.
             * \copydetails refl::descriptor::get_declared_members
             */
            static constexpr declared_member_types declared_members{  };

            /**
             * The list of declared and inherited member descriptors.
             * \copydetails refl::descriptor::get_members
             */
            static constexpr member_types members{  };

            /**
             * The name of the reflected type.
             * \copydetails refl::descriptor::get_name
             */
            static constexpr const auto name{ type_info::name };

            /**
             * The attributes of the reflected type.
             * \copydetails refl::descriptor::get_attributes
              */
            static constexpr const auto attributes{ type_info::attributes };

        };

        /**
         * Returns the full name of the descriptor
         *
         * \code{.cpp}
         * namespace ns {
         *   struct Foo {
         *     int x;
         *   };
         * }
         * REFL_AUTO(type(ns::Foo), field(x))
         *
         * get_name(reflect<Foo>()) -> "ns::Foo"
         * get_name(get_t<0, member_list<Foo>>()) -> "x"
         * \endcode
         */
        template <typename Descriptor>
        constexpr auto get_name(Descriptor d) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return d.name;
        }

        /**
         * Returns a const reference to the descriptor's attribute tuple.
         *
         * \code{.cpp}
         * struct Foo {};
         * REFL_AUTO(type(Foo, bases<>, ns::serializable()))
         *
         * get_attributes(reflect<Foo>()) -> const std::tuple<attr::base_types<>, ns::serializable>&
         * \endcode
         */
        template <typename Descriptor>
        constexpr const auto& get_attributes(Descriptor d) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return d.attributes;
        }

        /**
         * Returns a type_list of the descriptor's attribute types.
         *
         * \code{.cpp}
         * struct Foo {};
         * REFL_AUTO(type(Foo, bases<>, ns::serializable()))
         *
         * get_attribute_types(reflect<Foo>()) -> type_list<attr::base_types<>, ns::serializable>
         * \endcode
         */
        template <typename Descriptor>
        constexpr auto get_attribute_types(Descriptor d) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return trait::as_type_list_t<std::remove_cv_t<decltype(d.attributes)>>{};
        }

        /**
         * Returns a type_list of the declared base types of the type.
         * Combine with reflect_types to obtain type_descriptors for those types.
         * @see reflect_types
         *
         * \code{.cpp}
         * struct Animal {};
         * REFL_AUTO(type(Animal))
         * struct Mammal : Animal {};
         * REFL_AUTO(type(Mammal, bases<Animal>))
         * struct Dog : Mammal {}:
         * REFL_AUTO(type(Dog, bases<Mammal>))
         *
         * get_base_types(reflect<Dog>()) -> type_list<Mammal>
         * \endcode
         */
        template <typename TypeDescriptor>
        constexpr auto get_declared_base_types(TypeDescriptor t) noexcept
        {
            static_assert(trait::is_type_v<TypeDescriptor>);
            return t.declared_bases;
        }

        /**
         * Returns a type_list of the declared and inherited base types of the type.
         * Combine with reflect_types to obtain type_descriptors for those types.
         * @see reflect_types
         *
         * \code{.cpp}
         * struct Animal {};
         * REFL_AUTO(type(Animal))
         * struct Mammal : Animal {};
         * REFL_AUTO(type(Mammal, bases<Animal>))
         * struct Dog : Mammal {}:
         * REFL_AUTO(type(Dog, bases<Mammal>))
         *
         * get_base_types(reflect<Dog>()) -> type_list<Mammal, Animal>
         * \endcode
         */
        template <typename TypeDescriptor>
        constexpr auto get_base_types(TypeDescriptor t) noexcept
        {
            static_assert(trait::is_type_v<TypeDescriptor>);
            return t.bases;
        }

        /**
         * Returns a type_list of the declared members of the type.
         *
         * \code{.cpp}
         * struct Base {
         *  int val;
         * };
         * struct Foo : Base {
         *   int bar, baz;
         * };
         * REFL_AUTO(type(Foo, bases<Base>), field(bar), field(baz))
         * get_declared_members(reflect<Foo>()) -> type_list<field_descriptor<Foo, 0> /bar/, field_descriptor<Foo, 1> /baz/>
         * \endcode
         */
        template <typename TypeDescriptor>
        constexpr auto get_declared_members(TypeDescriptor t) noexcept
        {
            static_assert(trait::is_type_v<TypeDescriptor>);
            return t.declared_members;
        }

        /**
         * Returns a type_list of the declared and inherited members of the type.
         *
         * \code{.cpp}
         * struct Base {
         *  int val;
         * };
         * struct Foo : Base {
         *   int bar, baz;
         * };
         * REFL_AUTO(type(Foo, bases<Base>), field(bar), field(baz))
         * get_members(reflect<Foo>()) -> type_list<field_descriptor<Foo, 0> /bar/, field_descriptor<Foo, 1> /baz/, field_descriptor<Base, 0> /val/>
         * \endcode
         */
        template <typename TypeDescriptor>
        constexpr auto get_members(TypeDescriptor t) noexcept
        {
            static_assert(trait::is_type_v<TypeDescriptor>);
            return t.members;
        }

        /**
         * Returns the type_descriptor of declaring type of the member.
         *
         * \code{.cpp}
         * struct Foo {
         *   int bar;
         * };
         * REFL_AUTO(type(Foo), field(bar)
         * get_declarator(get_t<0, member_list<Foo>>()) -> type_descriptor<Foo>{}
         * \endcode
         */
        template <typename MemberDescriptor>
        constexpr auto get_declarator(MemberDescriptor d) noexcept
        {
            static_assert(trait::is_member_v<MemberDescriptor>);
            return d.declarator;
        }

        /**
         * Returns a pointer to the reflected field/function.
         * When the member is a function, the return value might be nullptr
         * if the type of the function pointer cannot be resolved.
         * @see is_resolved
         * @see can_resolve
         * @see resolve
         *
         * \code{.cpp}
         * struct Foo {
         *   int bar;
         *   static int baz;
         * };
         * REFL_AUTO(type(Foo), field(bar), field(baz))
         * get_pointer(get_t<0, member_list<Foo>>()) -> (int Foo::*) &Foo::bar
         * get_pointer(get_t<1, member_list<Foo>>()) -> (int*) &Foo::baz
         * \endcode
         */
        template <typename MemberDescriptor>
        constexpr auto get_pointer(MemberDescriptor d) noexcept
        {
            static_assert(trait::is_member_v<MemberDescriptor>);
            return d.pointer;
        }

        /**
         * Invokes the member with the specified arguments.
         *
         * \code{.cpp}
         * struct Foo {
         *   int bar = 1;
         *   static int baz = 5;
         *   void foobar(int x) { return x * 2; }
         *   static void foobaz(int x) { return x * 3; }
         * };
         * REFL_AUTO(type(Foo), field(bar), field(baz), func(foobar), func(foobaz))
         * invoke(get_t<0, member_list<Foo>(), Foo()) -> 1 (Foo().bar)
         * invoke(get_t<1, member_list<Foo>>()) -> 5 (Foo::baz)
         * invoke(get_t<2, member_list<Foo>(), Foo(), 10) -> 20 (Foo().foobar())
         * invoke(get_t<3, member_list<Foo>>()) -> 30 (Foo::foobaz())
         * \endcode
         */
        template <typename MemberDescriptor, typename... Args>
        constexpr auto invoke(MemberDescriptor d, Args&&... args) noexcept -> decltype(d(std::forward<Args>(args)...))
        {
            return d(std::forward<Args>(args)...);
        }

        /**
         * Checks whether the field is declared as static.
         *
         * \code{.cpp}
         * struct Foo {
         *   int bar;
         *   static int baz;
         * };
         * REFL_AUTO(type(Foo), field(bar), field(baz))
         * is_static(get_t<0, member_list<Foo>>()) -> false
         * is_static(get_t<1, member_list<Foo>>()) -> true
         * \endcode
         */
        template <typename FieldDescriptor>
        constexpr auto is_static(FieldDescriptor d) noexcept
        {
            static_assert(trait::is_field_v<FieldDescriptor>);
            return d.is_static;
        }

        /**
         * Checks whether the value type of the field is const-qualified.
         *
         * \code{.cpp}
         * struct Foo {
         *   int bar;
         *   const int baz;
         * };
         * REFL_AUTO(type(Foo), field(bar), field(baz))
         * is_const(get_t<0, member_list<Foo>>()) -> false
         * is_const(get_t<1, member_list<Foo>>()) -> true
         * \endcode
         */
        template <typename FieldDescriptor>
        constexpr auto is_const(FieldDescriptor d) noexcept
        {
            static_assert(trait::is_field_v<FieldDescriptor>);
            return d.is_const;
        }

        /**
         * The return type when invoking the specified descriptor using the provided argument types.
         * Argument coversion will be applied as per C++ rules.
         */
        template <typename FunctionDescriptor, typename... Args>
        using result_type = typename FunctionDescriptor::template result_type<Args...>;

        /**
         * Checks whether the function pointer was automatically resolved.
         *
         * \code{.cpp}
         * struct Foo {
         *   void bar();
         *   void bar(int);
         *   void baz();
         * };
         * REFL_AUTO(type(Foo), func(bar), func(baz))
         * is_resolved(get_t<0, member_list<Foo>>()) -> false
         * is_resolved(get_t<1, member_list<Foo>>()) -> true
         * \endcode
         */
        template <typename FunctionDescriptor>
        constexpr auto is_resolved(FunctionDescriptor d) noexcept
        {
            static_assert(trait::is_function_v<FunctionDescriptor>);
            return d.is_resolved;
        }

        /**
         * Checks whether the function pointer can be resolved as
         * a pointer of the specified type.
         *
         * \code{.cpp}
         * struct Foo {
         *   void bar();
         *   void bar(int);
         * };
         * REFL_AUTO(type(Foo), func(bar))
         * can_resolve<void(Foo::*)()>(get_t<0, member_list<Foo>>()) -> true
         * can_resolve<void(Foo::*)(int)>(get_t<0, member_list<Foo>>()) -> true
         * can_resolve<void(Foo::*)(std::string)>(get_t<0, member_list<Foo>>()) -> false
         * \endcode
         */
        template <typename Pointer, typename FunctionDescriptor>
        constexpr auto can_resolve(FunctionDescriptor d) noexcept
        {
            static_assert(trait::is_function_v<FunctionDescriptor>);
            return d.template can_resolve<Pointer>();
        }

        /**
         * Resolves the function pointer as a pointer of the specified type.
         *
         * \code{.cpp}
         * struct Foo {
         *   void bar();
         *   void bar(int);
         * };
         * REFL_AUTO(type(Foo), func(bar))
         * resolve<void(Foo::*)()>(get_t<0, member_list<Foo>>()) -> <&Foo::bar()>
         * resolve<void(Foo::*)(int)>(get_t<0, member_list<Foo>>()) -> <&Foo::bar(int)>
         * resolve<void(Foo::*)(std::string)>(get_t<0, member_list<Foo>>()) -> nullptr
         * \endcode
         */
        template <typename Pointer, typename FunctionDescriptor>
        constexpr auto resolve(FunctionDescriptor d) noexcept
        {
            static_assert(trait::is_function_v<FunctionDescriptor>);
            return d.template resolve<Pointer>();
        }

        /**
         * Checks whether T is a field descriptor.
         *
         * @see refl::descriptor::field_descriptor
         *
         * \code{.cpp}
         * REFL_AUTO(type(Foo), func(bar), field(baz))
         * is_function(get_t<0, member_list<Foo>>()) -> false
         * is_function(get_t<1, member_list<Foo>>()) -> true
         * \endcode
         */
        template <typename Descriptor>
        constexpr bool is_field(Descriptor) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return trait::is_field_v<Descriptor>;
        }

        /**
         * Checks whether T is a function descriptor.
         *
         * @see refl::descriptor::function_descriptor
         *
         * \code{.cpp}
         * REFL_AUTO(type(Foo), func(bar), field(baz))
         * is_function(get_t<0, member_list<Foo>>()) -> true
         * is_function(get_t<1, member_list<Foo>>()) -> false
         * \endcode
         */
        template <typename Descriptor>
        constexpr bool is_function(Descriptor) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return trait::is_function_v<Descriptor>;
        }

        /**
         * Checks whether T is a type descriptor.
         *
         * @see refl::descriptor::type_descriptor
         *
         * \code{.cpp}
         * REFL_AUTO(type(Foo))
         * is_type(reflect<Foo>>()) -> true
         * \endcode
         */
        template <typename Descriptor>
        constexpr bool is_type(Descriptor) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return trait::is_type_v<Descriptor>;
        }

        /**
         * Checks whether T has an attribute of type A.
         *
         * \code{.cpp}
         * REFL_AUTO(type(User), func(get_name, property()), func(set_name, property()))
         * has_attribute<attr::property>(get_t<0, member_list<User>>{}) -> true
         * \endcode
         */
        template <typename A, typename Descriptor>
        constexpr bool has_attribute(Descriptor) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return trait::contains_base_v<A, typename Descriptor::attribute_types>;
        }

        /**
         * Checks whether T has an attribute of that is a template instance of A.
         *
         * \code{.cpp}
         * REFL_AUTO(type(Random, debug{ [](auto os, auto){ os << "[Random]"; } }))
         * has_attribute<attr::debug>(reflect<Random>()) -> true
         * \endcode
         */
        template <template<typename...> typename A, typename Descriptor>
        constexpr bool has_attribute(Descriptor) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return trait::contains_instance_v<A, typename Descriptor::attribute_types>;
        }

        /**
         * Returns the value of the attribute A on T.
         *
         * \code{.cpp}
         * REFL_AUTO(type(User), func(get_name, property()), func(set_name, property()))
         * get_attribute<attr::property>(get_t<0, member_list<User>>{}) -> property{ friendly_name = nullopt }
         * \endcode
         */
        template <typename A, typename Descriptor>
        constexpr const A& get_attribute(Descriptor d) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return util::get<A>(d.attributes);
        }

        /**
         * Returns the value of the attribute A on T.
         *
         * \code{.cpp}
         * REFL_AUTO(type(Random, debug{ [](auto os, auto){ os << "[Random]"; } }))
         * get_attribute<attr::debug>(reflect<Random>()) -> instance of debug<LambdaType>
         * \endcode
         */
        template <template<typename...> typename A, typename Descriptor>
        constexpr const auto& get_attribute(Descriptor d) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return util::get_instance<A>(d.attributes);
        }

        /**
         * Checks whether T is a member descriptor marked with the property attribute.
         *
         * @see refl::attr::property
         * @see refl::descriptor::get_property
         *
         * \code{.cpp}
         * REFL_AUTO(type(User), func(get_name, property("user_name")), func(set_name, property()))
         * is_property(get_t<0, member_list<User>>{}) -> true
         * \endcode
         */
        template <typename MemberDescriptor>
        constexpr bool is_property(MemberDescriptor d) noexcept
        {
            static_assert(trait::is_member_v<MemberDescriptor>);
            return has_attribute<attr::property>(d);
        }

        /**
         * Gets the property attribute.
         *
         * @see refl::attr::property
         * @see refl::descriptor::is_property
         *
         * \code{.cpp}
         * REFL_AUTO(type(User), func(get_name, property("user_name")), func(set_name, property()))
         * *get_property(get_t<0, member_list<User>>{}).friendly_name -> "user_name"
         * \endcode
         */
        template <typename FunctionDescriptor>
        constexpr attr::property get_property(FunctionDescriptor d) noexcept
        {
            static_assert(trait::is_function_v<FunctionDescriptor>);
            return get_attribute<attr::property>(d);
        }

        namespace detail
        {
            struct placeholder
            {
                template <typename T>
                operator T() const;
            };
        } // namespace detail

        /**
         * Checks if T is a 0-arg const-qualified member function with a property attribute or a field.
         *
         * \code{.cpp}
         * REFL_AUTO(type(User), func(get_name, property()), func(set_name, property()))
         * is_readable(get_t<0, member_list<User>>{}) -> true
         * is_readable(get_t<1, member_list<User>>{}) -> false
         * \endcode
         */
        template <typename MemberDescriptor>
        constexpr bool is_readable(MemberDescriptor) noexcept
        {
            static_assert(trait::is_member_v<MemberDescriptor>);
            if constexpr (trait::is_property_v<MemberDescriptor>) {
                if constexpr (std::is_invocable_v<MemberDescriptor, const typename MemberDescriptor::declaring_type&>) {
                    using return_type = typename MemberDescriptor::template return_type<const typename MemberDescriptor::declaring_type&>;
                    return !std::is_void_v<return_type>;
                }
                else {
                    return false;
                }
            }
            else {
                return trait::is_field_v<MemberDescriptor>;
            }
        }

        /**
         * Checks if T is a 1-arg non-const-qualified member function with a property attribute or a non-const field.
         *
         * \code{.cpp}
         * struct User { std::string get_name() const; }
         * REFL_AUTO(type(User), func(get_name, property()), func(set_name, property()))
         * is_writable(get_t<0, member_list<User>>{}) -> false
         * is_writable(get_t<1, member_list<User>>{}) -> true
         * \endcode
         */
        template <typename MemberDescriptor>
        constexpr bool is_writable(MemberDescriptor) noexcept
        {
            static_assert(trait::is_member_v<MemberDescriptor>);
            if constexpr (trait::is_property_v<MemberDescriptor>) {
                return std::is_invocable_v<MemberDescriptor, typename MemberDescriptor::declaring_type&, detail::placeholder>;
            }
            else if constexpr (trait::is_field_v<MemberDescriptor>) {
                return !std::is_const_v<typename trait::remove_qualifiers_t<MemberDescriptor>::value_type>;
            }
            else {
                return false;
            }
        }

        namespace detail
        {
            template <typename T>
            struct get_type_descriptor
            {
                typedef type_descriptor<T> type;
            };
        } // namespace detail

        /**
         * Checks if a type has a bases attribute.
         *
         * @deprecated Use has_base_types in combination with reflect_types instead.
         * @see refl::attr::bases
         * @see refl::descriptor::get_bases
         *
         * \code{.cpp}
         * REFL_AUTO(type(Dog, bases<Animal>))
         * has_bases(reflect<Dog>()) -> true
         * \endcode
         */
        template <typename TypeDescriptor>
        [[deprecated]] constexpr auto has_bases(TypeDescriptor t) noexcept
        {
            static_assert(trait::is_type_v<TypeDescriptor>);
            return has_attribute<attr::base_types>(t);
        }

        /**
         * Returns a list of the type_descriptor<T>s of the base types of the target,
         * as specified by the bases<A, B, ...> attribute.
         *
         * @deprecated Use get_base_types in combination with reflect_types instead.
         * @see refl::attr::bases
         * @see refl::descriptor::has_bases
         *
         * \code{.cpp}
         * REFL_AUTO(type(Dog, bases<Animal>))
         * get_bases(reflect<Dog>()) -> type_list<type_descriptor<Animal>>
         * \endcode
         */
        template <typename TypeDescriptor>
        [[deprecated]] constexpr auto get_bases(TypeDescriptor t) noexcept
        {
            static_assert(trait::is_type_v<TypeDescriptor>);
            static_assert(has_bases(t), "Target type does not have a bases<A, B, ...> attribute.");

            constexpr auto bases = get_attribute<attr::base_types>(t);
            using base_types = typename decltype(bases)::list_type;
            return trait::map_t<detail::get_type_descriptor, base_types>{};
        }

        /**
         * Returns the unqualified name of the type, discarding the namespace and typenames (if a template type).
         *
         * \code{.cpp}
         * get_simple_name(reflect<std::vector<float>>()) -> "vector"
         * \endcode
         */
        template <typename TypeDescriptor>
        constexpr auto get_simple_name(TypeDescriptor t)
        {
            static_assert(trait::is_type_v<TypeDescriptor>);
            constexpr size_t template_start = t.name.find('<');
            constexpr size_t scope_last = t.name.rfind(':', template_start);
            if constexpr (scope_last == const_string<0>::npos) {
                return t.name;
            }
            else {
                return t.name.template substr<scope_last + 1, template_start - scope_last - 1>();
            }
        }

        /**
         * Returns the debug name of T (In the form of 'declaring_type::member_name') as a const_string.
         *
         * \code{.cpp}
         * REFL_AUTO(type(Point), field(x), field(y))
         * get_debug_name_const(get_t<0, member_list<Point>>{}) -> "Point::x"
         * \endcode
         */
        template <typename MemberDescriptor>
        constexpr auto get_debug_name_const(MemberDescriptor d)
        {
            static_assert(trait::is_member_v<MemberDescriptor>);
            return d.declarator.name + "::" + d.name;
        }

        /**
         * Returns the debug name of T. (In the form of 'declaring_type::member_name').
         * \code{.cpp}
         * REFL_AUTO(type(Point), field(x), field(y))
         * get_debug_name(get_t<0, member_list<Point>>{}) -> "Point::x"
         * \endcode
         */
        template <typename MemberDescriptor>
        const char* get_debug_name(MemberDescriptor d)
        {
            static_assert(trait::is_member_v<MemberDescriptor>);
            static const std::string name(get_debug_name_const(d).str());
            return name.c_str();
        }

        namespace detail
        {
            constexpr bool is_upper(char ch)
            {
                return ch >= 'A' && ch <= 'Z';
            }

            constexpr char to_upper(char ch)
            {
                return ch >= 'a' && ch <= 'z'
                    ? char(ch + ('A' - 'a'))
                    : ch;
            }

            constexpr char to_lower(char ch)
            {
                return ch >= 'A' && ch <= 'Z'
                    ? char(ch + ('a' - 'A'))
                    : ch;
            }

            template <typename T, bool PreferUpper>
            constexpr auto normalize_bare_accessor_name()
            {
                constexpr auto str = T::name.template substr<3>();
                if constexpr (str.data[0] == '_') {
                    return str.template substr<1>();
                }
                else if constexpr (!PreferUpper && str.data[0] >= 'A' && str.data[0] <= 'Z') {
                    return make_const_string(to_lower(str.data[0])) + str.template substr<1>();
                }
                else if constexpr (PreferUpper) {
                    return make_const_string(to_upper(str.data[0])) + str.template substr<1>();
                }
                else {
                    return str;
                }
            }

            template <typename T>
            constexpr auto normalize_accessor_name(const T)
            {
                constexpr T t{};
                if constexpr (t.name.size > 3) {
                    constexpr auto prefix = t.name.template substr<0, 3>();
                    constexpr bool cont_snake_or_camel = (t.name.size > 4 && t.name.data[3] == '_' && !is_upper(t.name.data[4])) || is_upper(t.name.data[3]);
                    constexpr bool cont_pascal = is_upper(t.name.data[3]);

                    if constexpr ((is_readable(T{}) && ((prefix == "Get" && cont_pascal) || (prefix == "get" && cont_snake_or_camel)))
                        || (is_writable(T{}) && ((prefix == "Set" && cont_pascal) || (prefix == "set" && cont_snake_or_camel)))) {
                        constexpr bool prefer_upper = is_upper(prefix.data[0]);
                        return normalize_bare_accessor_name<T, prefer_upper>();
                    }
                    else {
                        return t.name;
                    }
                }
                else {
                    return t.name;
                }
            }

            template <typename T>
            constexpr auto get_display_name(const T t) noexcept
            {
                if constexpr (trait::is_property_v<T>) {
                    if constexpr (util::get<attr::property>(t.attributes).friendly_name) {
                        return REFL_MAKE_CONST_STRING(*util::get<attr::property>(t.attributes).friendly_name);
                    }
                    else {
                        return detail::normalize_accessor_name(t);
                    }
                }
                else {
                    return t.name;
                }
            }

            template <template <typename, size_t> typename MemberDescriptor, typename T, size_t N>
            constexpr size_t get_member_index(MemberDescriptor<T, N>) noexcept
            {
                return N;
            }

            // Compilers only instantiate templates once per set of template parameters.
            // Since each lambda is it's distinct type, and since we end up filtering
            // by these predicates in several places in the codebase, it is better to have
            // these lamdas defined here, to increase the likelihood that a template
            // instantiation of `util::filter` can be reused.
            static constexpr auto is_readable_p = [](auto m) { return is_readable(m); };
            static constexpr auto is_writable_p = [](auto m) { return is_writable(m); };

            template <typename Member>
            static constexpr auto display_name_equals_p = [](auto m) {
                return get_display_name_const(m) == get_display_name_const(Member{});
            };

            template <typename WritableMember>
            static constexpr bool has_reader_search(WritableMember)
            {
#ifdef REFL_DISALLOW_SEARCH_FOR_RW
                static_assert(WritableMember::name.data[0] == 0,
                    "REFL_DISALLOW_SEARCH_FOR_RW is defined. Make sure your property getters and setter are defined one after the other!");
#endif
                using member_types = typename type_descriptor<typename WritableMember::declaring_type>::declared_member_types;
                // Fallback to a slow linear search.
                using property_types = typename trait::filter_t<trait::is_property, member_types>;
                constexpr auto readable_properties = filter(property_types{}, detail::is_readable_p);
                return contains(readable_properties, display_name_equals_p<WritableMember>);
            }

            template <typename ReadableMember>
            static constexpr bool has_writer_search(ReadableMember)
            {
#ifdef REFL_DISALLOW_SEARCH_FOR_RW
                static_assert(ReadableMember::name.data[0] == 0,
                    "REFL_DISALLOW_SEARCH_FOR_RW is defined. Make sure your property getters and setter are defined one after the other!");
#endif
                using member_types = typename type_descriptor<typename ReadableMember::declaring_type>::declared_member_types;
                // Fallback to a slow linear search.
                using property_types = typename trait::filter_t<trait::is_property, member_types>;
                constexpr auto writable_properties = filter(property_types{}, detail::is_writable_p);
                return contains(writable_properties, display_name_equals_p<ReadableMember>);
            }

            template <typename WritableMember>
            static constexpr auto get_reader_search(WritableMember)
            {
#ifdef REFL_DISALLOW_SEARCH_FOR_RW
                static_assert(WritableMember::name.data[0] == 0,
                    "REFL_DISALLOW_SEARCH_FOR_RW is defined. Make sure your property getters and setter are defined one after the other!");
#endif
                using member_types = typename type_descriptor<typename WritableMember::declaring_type>::declared_member_types;
                // Fallback to a slow linear search.
                using property_types = typename trait::filter_t<trait::is_property, member_types>;
                constexpr auto readable_properties = filter(property_types{}, detail::is_readable_p);
                return find_one(readable_properties, display_name_equals_p<WritableMember>);
            }

            template <typename ReadableMember>
            static constexpr auto get_writer_search(ReadableMember)
            {
#ifdef REFL_DISALLOW_SEARCH_FOR_RW
                static_assert(ReadableMember::name.data[0] == 0,
                    "REFL_DISALLOW_SEARCH_FOR_RW is defined. Make sure your property getters and setter are defined one after the other!");
#endif
                using member_types = typename type_descriptor<typename ReadableMember::declaring_type>::declared_member_types;
                // Fallback to a slow linear search.
                using property_types = typename trait::filter_t<trait::is_property, member_types>;
                constexpr auto writable_properties = filter(property_types{}, detail::is_writable_p);
                return find_one(writable_properties, display_name_equals_p<ReadableMember>);
            }
        } // namespace detail

        /**
         * Returns the display name of T.
         * Uses the friendly_name of the property attribute, or the normalized name if no friendly_name was provided.
         *
         * \code{.cpp}
         * struct Foo {
         *   int get_foo() const;
         *   int GetFoo() const;
         *   int get_non_const() /missing const/;
         *   int get_custom() const;
         * };
         * REFL_AUTO(
         *   type(Foo),
         *   func(get_foo, property()),
         *   func(GetFoo, property()),
         *   func(get_non_const, property()),
         *   func(get_custom, property("value")),
         * )
         *
         * get_display_name(get_t<0, member_list<Foo>>{}) -> "foo"
         * get_display_name(get_t<1, member_list<Foo>>{}) -> "Foo"
         * get_display_name(get_t<2, member_list<Foo>>{}) -> "get_non_const"
         * get_display_name(get_t<3, member_list<Foo>>{}) -> "value"
         * \endcode
         */
        template <typename Descriptor>
        const char* get_display_name(Descriptor d) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            static const std::string name(detail::get_display_name(d));
            return name.c_str();
        }

        /**
         * Returns the display name of T as a const_string<N>.
         * Uses the friendly_name of the property attribute, or the normalized name if no friendly_name was provided.
         * @see get_display_name
         */
        template <typename Descriptor>
        constexpr auto get_display_name_const(Descriptor d) noexcept
        {
            static_assert(trait::is_descriptor_v<Descriptor>);
            return detail::get_display_name(d);
        }

        /**
         * Checks if there exists a member that has the same display name as the one provied and is writable.
         * For getter methods with a property attribute, the return value will be true if there exists a
         * reflected setter method with a property with the same display name (property name normalization applies automatically).
         * For fields, returns true only if the field is writable.
         */
        template <typename ReadableMember>
        constexpr bool has_writer(ReadableMember member)
        {
            static_assert(is_writable(member) || is_property(member));
            if constexpr (is_writable(member)) {
                return true;
            }
            else {
                [[maybe_unused]] constexpr auto match = [](auto m) {
                    return is_property(m) && is_writable(m) && get_display_name_const(m) == get_display_name_const(ReadableMember{});
                };

                using member_types = typename type_descriptor<typename ReadableMember::declaring_type>::declared_member_types;
                constexpr auto member_index = detail::get_member_index(member);

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != 0) {
                    using likely_match = trait::get_t<member_index - 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return true;
                    }
                }

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != member_types::size - 1) {
                    using likely_match = trait::get_t<member_index + 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return true;
                    }
                    else {
                        return detail::has_writer_search(member);
                    }
                }
                else {
                    return detail::has_writer_search(member);
                }
            }
        }

        /**
         * Checks if there exists a member that has the same display name as the one provied and is readable.
         * For setter methods with a property attribute, the return value will be true if there exists a
         * reflected getter method with a property with the same display name (property name normalization applies automatically).
         * For fields, returns true.
         */
        template <typename WritableMember>
        constexpr bool has_reader(WritableMember member)
        {
            static_assert(is_readable(member) || is_property(member));
            if constexpr (is_readable(member)) {
                return true;
            }
            else {
                [[maybe_unused]] constexpr auto match = [](auto m) {
                    return is_property(m) && is_readable(m) && get_display_name_const(m) == get_display_name_const(WritableMember{});
                };

                using member_types = typename type_descriptor<typename WritableMember::declaring_type>::declared_member_types;
                constexpr auto member_index = detail::get_member_index(member);

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != member_types::size - 1) {
                    using likely_match = trait::get_t<member_index + 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return true;
                    }
                }

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != 0) {
                    using likely_match = trait::get_t<member_index - 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return true;
                    }
                    else {
                        return detail::has_reader_search(member);
                    }
                }
                else {
                    return detail::has_reader_search(member);
                }
            }
        }

        /**
         * Returns a member that has the same display name as the one provied and is writable.
         * For getter methods with a property attribute, the return value will the
         * reflected setter method with a property with the same display name (property name normalization applies automatically).
         * For fields, returns the same descriptor if writable.
         */
        template <typename ReadableMember>
        constexpr auto get_writer(ReadableMember member)
        {
            static_assert(is_writable(member) || is_property(member));
            if constexpr (is_writable(member)) {
                return member;
            }
            else if constexpr (has_writer(member)) {
                constexpr auto match = [](auto m) {
                    return is_property(m) && is_writable(m) && get_display_name_const(m) == get_display_name_const(ReadableMember{});
                };

                using member_types = typename type_descriptor<typename ReadableMember::declaring_type>::declared_member_types;
                constexpr auto member_index = detail::get_member_index(member);

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != 0) {
                    using likely_match = trait::get_t<member_index - 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return likely_match{};
                    }
                }

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != member_types::size - 1) {
                    using likely_match = trait::get_t<member_index + 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return likely_match{};
                    }
                    else {
                        return detail::get_writer_search(member);
                    }
                }
                else {
                    return detail::get_writer_search(member);
                }
            }
            else {
                static_assert(has_writer(member), "The property is not writable (could not find a setter method)!");
            }
        }

        /**
         * Returns a member that has the same display name as the one provied and is readable.
         * For setter methods with a property attribute, the return value will be a
         * reflected getter method with a property with the same display name (property name normalization applies automatically).
         * For fields, returns the same descriptor.
         */
        template <typename WritableMember>
        constexpr auto get_reader(WritableMember member)
        {
            static_assert(is_readable(member) || is_property(member));
            if constexpr (is_readable(member)) {
                return member;
            }
            else if constexpr (has_reader(member)) {
                constexpr auto match = [](auto m) {
                    return is_property(m) && is_readable(m) && get_display_name_const(m) == get_display_name_const(WritableMember{});
                };

                using member_types = typename type_descriptor<typename WritableMember::declaring_type>::declared_member_types;
                constexpr auto member_index = detail::get_member_index(member);

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != member_types::size - 1) {
                    using likely_match = trait::get_t<member_index + 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return likely_match{};
                    }
                }

                // Optimisation for the getter defined after setter pattern.
                if constexpr (member_index != 0) {
                    using likely_match = trait::get_t<member_index - 1, member_types>;
                    if constexpr (match(likely_match{})) {
                        return likely_match{};
                    }
                    else {
                        return detail::get_reader_search(member);
                    }
                }
                else {
                    return detail::get_reader_search(member);
                }
            }
            else {
                static_assert(has_reader(member), "The property is not readable (could not find a getter method)!");
            }
        }

    } // namespace descriptor

    using descriptor::member_list;
    using descriptor::declared_member_list;
    using descriptor::field_descriptor;
    using descriptor::function_descriptor;
    using descriptor::type_descriptor;

    /** Returns true if the type T is reflectable. */
    template <typename T>
    constexpr bool is_reflectable() noexcept
    {
        return trait::is_reflectable_v<T>;
    }

    /** Returns true if the non-qualified type T is reflectable.*/
    template <typename T>
    constexpr bool is_reflectable(const T&) noexcept
    {
        return trait::is_reflectable_v<T>;
    }

    /** Returns the type descriptor for the type T. */
    template<typename T>
    constexpr type_descriptor<T> reflect() noexcept
    {
        return {};
    }

    /** Returns the type descriptor for the non-qualified type T. */
    template<typename T>
    constexpr type_descriptor<T> reflect(const T&) noexcept
    {
        return {};
    }

#ifndef REFL_DETAIL_FORCE_EBO
#ifdef _MSC_VER
#define REFL_DETAIL_FORCE_EBO __declspec(empty_bases)
#else
#define REFL_DETAIL_FORCE_EBO
#endif
#endif

    /**
     * @brief Contains utilities that can have runtime-overhead (like proxy, debug, invoke)
     */
    namespace runtime
    {
        template <typename Derived, typename Target>
        struct REFL_DETAIL_FORCE_EBO proxy;

        namespace detail
        {
            template <typename T>
            struct get_member_info;

            template <typename T, size_t N>
            struct get_member_info<refl::function_descriptor<T, N>>
            {
                using type = refl::detail::member_info<T, N>;
            };

            template <typename T, size_t N>
            struct get_member_info<refl::field_descriptor<T, N>>
            {
                using type = refl::detail::member_info<T, N>;
            };

            template <typename T, typename U>
            constexpr T& static_ref_cast(U& value) noexcept
            {
                return static_cast<T&>(value);
            }

            template <typename T, typename U>
            constexpr const T& static_ref_cast(const U& value) noexcept
            {
                return static_cast<const T&>(value);
            }

            template <typename... Results>
            constexpr type_list<Results...> get_members_skip_shadowed(type_list<>, type_list<Results...>)
            {
                return {};
            }

            template <typename Member, typename... Members, typename... Results>
            constexpr auto get_members_skip_shadowed(type_list<Member, Members...>, type_list<Results...>)
            {
                if constexpr ((... || (Results::name == Member::name))) {
                    return get_members_skip_shadowed(type_list<Members...>{}, type_list<Results...>{});
                }
                else {
                    return get_members_skip_shadowed(type_list<Members...>{}, type_list<Results..., Member>{});
                }
            }

            template <typename T>
            using members_skip_shadowed = decltype(get_members_skip_shadowed(member_list<T>{}, type_list<>{}));

            /** Implements a proxy for a reflected function. */
            template <typename Derived, typename Func>
            struct REFL_DETAIL_FORCE_EBO function_proxy : public get_member_info<Func>::type::template remap<function_proxy<Derived, Func>>
            {
                function_proxy()
                {
                }

                template <typename Self, typename... Args>
                static constexpr decltype(auto) invoke_impl(Self&& self, Args&& ... args)
                {
                    return Derived::template invoke_impl<Func>(static_ref_cast<Derived>(self), std::forward<Args>(args)...);
                }
            };

            template <typename, typename>
            struct REFL_DETAIL_FORCE_EBO function_proxies;

            /** Implements a proxy for all reflected functions. */
            template <typename Derived, typename... Members>
            struct REFL_DETAIL_FORCE_EBO function_proxies<Derived, type_list<Members...>> : public function_proxy<Derived, Members>...
            {
            };

            /** Implements a proxy for a reflected field. */
            template <typename Derived, typename Field>
            struct REFL_DETAIL_FORCE_EBO field_proxy : public get_member_info<Field>::type::template remap<field_proxy<Derived, Field>>
            {
                field_proxy()
                {
                }

                template <typename Self, typename... Args>
                static constexpr decltype(auto) invoke_impl(Self&& self, Args&& ... args)
                {
                    return Derived::template invoke_impl<Field>(static_ref_cast<Derived>(self), std::forward<Args>(args)...);
                }
            };


            template <typename, typename>
            struct REFL_DETAIL_FORCE_EBO field_proxies;

            /** Implements a proxy for all reflected fields. */
            template <typename Derived, typename... Members>
            struct REFL_DETAIL_FORCE_EBO field_proxies<Derived, type_list<Members...>> : public field_proxy<Derived, Members>...
            {
            };

            template <typename T>
            using functions = trait::filter_t<trait::is_function, members_skip_shadowed<T>>;

            template <typename T>
            using fields = trait::filter_t<trait::is_field, members_skip_shadowed<T>>;

        } // namespace detail

        /**
         * @brief A proxy object that has a static interface identical to the reflected functions and fields of the target.
         *
         * A proxy object that has a static interface identical to the reflected functions and fields of the target.
         * Users should inherit from this class and specify an invoke_impl(Member member, Args&&... args) function.
         *
         * # Examples:
         * \code{.cpp}
         * template <typename T>
         * struct dummy_proxy : refl::runtime::proxy<dummy_proxy<T>, T> {
         *     template <typename Member, typename Self, typename... Args>
         *     static int invoke_impl(Self&& self, Args&&... args) {
         *          std::cout << get_debug_name(Member()) << " called with " << sizeof...(Args) << " parameters!\n";
         *          return 0;
         *     }
         * };
         * \endcode
         */
        template <typename Derived, typename Target>
        struct REFL_DETAIL_FORCE_EBO proxy
            : public detail::function_proxies<proxy<Derived, Target>, detail::functions<Target>>
            , public detail::field_proxies<proxy<Derived, Target>, detail::fields<Target>>
        {
            static_assert(
                sizeof(detail::function_proxies<proxy<Derived, Target>, detail::functions<Target>>) == 1 &&
                sizeof(detail::field_proxies<proxy<Derived, Target>, detail::fields<Target>>) == 1,
                "Multiple inheritance EBO did not kick in! "
                "You could try defining the REFL_DETAIL_FORCE_EBO macro appropriately to enable it on the required types. "
                "Default for MSC is `__declspec(empty_bases)`.");

            static_assert(
                trait::is_reflectable_v<Target>,
                "Target type must be reflectable!");

            typedef Target target_type;

            constexpr proxy() noexcept {}

        private:

            template <typename P, typename F>
            friend struct detail::function_proxy;

            template <typename P, typename F>
            friend struct detail::field_proxy;

            // Called by one of the function_proxy/field_proxy bases.
            template <typename Member, typename Self, typename... Args>
            static constexpr decltype(auto) invoke_impl(Self&& self, Args&& ... args)
            {
                return Derived::template invoke_impl<Member>(detail::static_ref_cast<Derived>(self), std::forward<Args>(args)...);
            }

        };

    } // namespace runtime

    namespace trait
    {
        template <typename>
        struct is_proxy;

        template <typename T>
        struct is_proxy
        {
        private:
            template <typename Derived, typename Target>
            static std::true_type test(runtime::proxy<Derived, Target>*);
            static std::false_type test(...);
        public:
            static constexpr bool value{ !std::is_reference_v<T> && decltype(test(std::declval<remove_qualifiers_t<T>*>()))::value };
        };

        template <typename T>
        [[maybe_unused]] static constexpr bool is_proxy_v{ is_proxy<T>::value };
    }

    namespace runtime
    {
        template <typename CharT, typename T>
        void debug(std::basic_ostream<CharT>& os, const T& value, bool compact = false);

        namespace detail
        {
            template <typename CharT, typename T, typename = decltype(std::declval<std::basic_ostream<CharT>&>() << std::declval<T>())>
            std::true_type is_ostream_printable_test(int);

            template <typename CharT, typename T>
            std::false_type is_ostream_printable_test(...);

            template <typename CharT, typename T>
            constexpr bool is_ostream_printable_v{ decltype(is_ostream_printable_test<CharT, T>(0))::value };

            namespace
            {
                [[maybe_unused]] int next_depth(int depth)
                {
                    return depth == -1 || depth > 8
                        ? -1
                        : depth + 1;
                }
            }

            template <typename CharT>
            void indent(std::basic_ostream<CharT>& os, int depth)
            {
                for (int i = 0; i < depth; i++) {
                    os << "    ";
                }
            }

            template <typename CharT, typename T>
            void debug_impl(std::basic_ostream<CharT>& os, const T& value, [[maybe_unused]] int depth);

            template <typename CharT, typename T>
            void debug_detailed(std::basic_ostream<CharT>& os, const T& value, int depth)
            {
                using type_descriptor = type_descriptor<T>;
                bool compact = depth == -1;
                // print type with members enclosed in braces
                os << type_descriptor::name << " { ";
                if (!compact) os << '\n';

                constexpr auto readable_members = filter(type_descriptor::members, [](auto member) { return is_readable(member); });
                for_each(readable_members, [&](auto member, [[maybe_unused]] auto index) {
                    int new_depth = next_depth(depth);

                    indent(os, new_depth);
                    os << get_display_name(member) << " = ";

                    if constexpr (util::contains_instance<attr::debug>(member.attributes)) {
                        // use the debug attribute to print
                        auto debug_attr = util::get_instance<attr::debug>(member.attributes);
                        debug_attr.write(os, value);
                    }
                    else {
                        debug_impl(os, member(value), new_depth);
                    }

                    if (!compact || index + 1 != readable_members.size) {
                        os << ", ";
                    }
                    if (!compact) {
                        indent(os, depth);
                        os << '\n';
                    }
                });

                if (compact) os << ' ';
                indent(os, depth);
                os << '}';
            }

            template <typename CharT, typename T>
            void debug_reflectable(std::basic_ostream<CharT>& os, const T& value, [[maybe_unused]] int depth)
            {
                using type_descriptor = type_descriptor<T>;
                if constexpr (trait::contains_instance_v<attr::debug, typename type_descriptor::attribute_types>) {
                    // use the debug attribute to print
                    auto debug_attr = util::get_instance<attr::debug>(type_descriptor::attributes);
                    debug_attr.write(os, value);
                }
                else if constexpr (detail::is_ostream_printable_v<CharT, T>) {
                    // type supports printing natively, just use that
                    os << value;
                }
                else {
                    debug_detailed(os, value, depth);
                }
            }

            template <typename CharT, typename T>
            void debug_container(std::basic_ostream<CharT>& os, const T& value, int depth)
            {
                bool compact = depth == -1;
                os << "[";

                auto end = value.end();
                for (auto it = value.begin(); it != end; ++it)
                {
                    if (!compact) os << '\n';
                    int new_depth = next_depth(depth);
                    indent(os, new_depth);

                    debug_impl(os, *it, new_depth);
                    if (std::next(it, 1) != end) {
                        os << ", ";
                    }
                    else if (!compact) {
                        os << '\n';
                    }
                }

                indent(os, depth);
                os << "]";
            }

            template <typename CharT, typename T>
            void debug_impl(std::basic_ostream<CharT>& os, const T& value, [[maybe_unused]] int depth)
            {
                using no_pointer_t = std::remove_pointer_t<T>;

                if constexpr (std::is_same_v<bool, T>) {
                    os << (value ? "true" : "false");
                }
                else if constexpr (std::is_pointer_v<T> && !std::is_void_v<no_pointer_t> && trait::is_reflectable_v<no_pointer_t>) {
                    if (value == nullptr) {
                        os << "nullptr";
                    }
                    else {
                        os << '&';
                        debug_impl(os, *value, -1);
                    }
                }
                else if constexpr (trait::is_reflectable_v<T>) {
                    debug_reflectable(os, value, depth);
                }
                else if constexpr (detail::is_ostream_printable_v<CharT, T>) {
                    os << value;
                }
                else if constexpr (trait::is_container_v<T>) {
                    debug_container(os, value, depth);
                }
                else {
                    os << "(not printable)";
                }
            }
        }

        /**
         * Writes the debug representation of value to the given std::ostream.
         * Calls the function specified by the debug<F> attribute whenever possible,
         * before falling back to recursively interating the members and printing them.
         * Takes an optional arguments specifying whether to print a compact representation.
         * The compact representation contains no newlines.
         */
        template <typename CharT, typename T>
        void debug(std::basic_ostream<CharT>& os, const T& value, [[maybe_unused]] bool compact)
        {
            static_assert(trait::is_reflectable_v<T> || trait::is_container_v<T> || detail::is_ostream_printable_v<CharT, T>,
                "Type is not reflectable, not a container of reflectable types and does not support operator<<(std::ostream&, T)!");

            detail::debug_impl(os, value, compact ? -1 : 0);
        }

        /**
         * Writes the compact debug representation of the provided values to the given std::ostream.
         */
        template <typename CharT, typename... Ts>
        void debug_all(std::basic_ostream<CharT>& os, const Ts&... values)
        {
            refl::runtime::debug(os, std::forward_as_tuple(static_cast<const Ts&>(values)...), true);
        }

        /**
         * Writes the debug representation of the provided value to an std::string and returns it.
         * Takes an optional arguments specifying whether to print a compact representation.
         * The compact representation contains no newlines.
         */
        template <typename CharT = char, typename T>
        std::basic_string<CharT> debug_str(const T& value, bool compact = false)
        {
            std::basic_stringstream<CharT> ss;
            debug(ss, value, compact);
            return ss.str();
        }

        /**
         * Writes the compact debug representation of the provided values to an std::string and returns it.
         */
        template <typename CharT = char, typename... Ts>
        std::basic_string<CharT> debug_all_str(const Ts&... values)
        {
            return refl::runtime::debug_str(std::forward_as_tuple(static_cast<const Ts&>(values)...), true);
        }

        /**
         * Invokes the specified member with the provided arguments.
         * When used with a member that is a field, the function gets or sets the value of the field.
         * The list of members is initially filtered by the type of the arguments provided.
         * THe filtered list is then searched at runtime by member name for the specified member
         * and that member is then invoked by operator(). If no match is found,
         * an std::runtime_error is thrown.
         */
        template <typename U, typename T, typename... Args>
        U invoke(T&& target, const char* name, Args&&... args)
        {
            using type = std::remove_reference_t<T>;
            static_assert(refl::trait::is_reflectable_v<type>, "Unsupported type!");
            typedef type_descriptor<type> type_descriptor;

            std::conditional_t<std::is_void_v<U>, bool, std::optional<U>> result{};

            for_each(type_descriptor::members, [&](auto member) {
                using member_t = decltype(member);
                if (result) return;

                if constexpr (std::is_invocable_r_v<U, decltype(member), T, Args...>) {
                    if constexpr (trait::is_member_v<member_t>) {
                        if (std::strcmp(member.name.c_str(), name) == 0) {
                            if constexpr (std::is_void_v<U>) {
                                member(target, std::forward<Args>(args)...);
                                result = true;
                            }
                            else {
                                result.emplace(member(target, std::forward<Args>(args)...));
                            }
                        }
                    }
                }
            });

            if (!result) {
                throw std::runtime_error(std::string("The member ")
                    + type_descriptor::name.str() + "::" + name
                    + " is not compatible with the provided parameters or return type, is not reflected or does not exist!");
            }
            if constexpr (!std::is_void_v<U>) {
                return std::move(*result);
            }
        }

    } // namespace runtime

} // namespace refl

namespace refl::detail
{
    constexpr bool validate_attr_unique(type_list<>) noexcept
    {
        return true;
    }

    /** Statically asserts that all types in Ts... are unique. */
    template <typename T, typename... Ts>
    constexpr bool validate_attr_unique(type_list<T, Ts...>) noexcept
    {
        constexpr bool cond = (... && (!std::is_same_v<T, Ts> && validate_attr_unique(type_list<Ts>{})));
        static_assert(cond, "Some of the attributes provided have duplicate types!");
        return cond;
    }

    template <typename Req, typename Attr>
    constexpr bool validate_attr_usage() noexcept
    {
        return std::is_base_of_v<Req, Attr>;
    }

    /**
     * Statically asserts that all arguments inherit
     * from the appropriate bases to be used with Req.
     * Req must be one of the types defined in attr::usage.
     */
    template <typename Req, typename... Args>
    constexpr auto make_attributes(Args&&... args) noexcept
    {
        constexpr bool check_unique = validate_attr_unique(type_list<Args...>{});
        static_assert(check_unique, "Some of the supplied attributes cannot be used on this declaration!");

        constexpr bool check_usage = (... && validate_attr_usage<Req, trait::remove_qualifiers_t<Args>>());
        static_assert(check_usage, "Some of the supplied attributes cannot be used on this declaration!");

        return std::make_tuple(std::forward<Args>(args)...);
    }

    template <typename T, typename...>
    struct head
    {
        typedef T type;
    };

    /**
     * Accesses the first type T of Ts...
     * Used to allow for SFIANE to kick in in the implementation of REFL_FUNC.
     */
    template <typename T, typename... Ts>
    using head_t = typename head<T, Ts...>::type;

    template <typename T, typename U>
    struct transfer_const
    {
        using type = std::conditional_t<std::is_const_v<T>, std::add_const_t<U>, U>;
    };

    template <typename T, typename U>
    struct transfer_volatile
    {
        using type = std::conditional_t<std::is_volatile_v<T>, std::add_volatile_t<U>, U>;
    };

    template <typename T, typename U>
    struct transfer_cv : transfer_const<T, typename transfer_volatile<T, U>::type>
    {
    };

    template <typename T, typename U>
    struct transfer_lvalue_ref
    {
        using type = std::conditional_t<std::is_lvalue_reference_v<T>, std::add_lvalue_reference_t<U>, U>;
    };

    template <typename T, typename U>
    struct transfer_rvalue_ref
    {
        using type = std::conditional_t<std::is_rvalue_reference_v<T>, std::add_rvalue_reference_t<U>, U>;
    };

    template <typename T, typename U>
    struct transfer_ref : transfer_rvalue_ref<T, typename transfer_lvalue_ref<T, U>::type>
    {
    };

    template <typename T, typename U>
    struct transfer_cvref : transfer_ref<T, typename transfer_cv<std::remove_reference_t<T>, U>::type>
    {
    };

    template <typename T, typename U>
    constexpr auto forward_cast(std::remove_reference_t<T>& t) -> decltype(static_cast<typename transfer_cvref<T, U>::type&&>(t))
    {
        return static_cast<typename transfer_cvref<T, U>::type&&>(t);
    }

    template <typename T, typename U>
    constexpr auto forward_cast(std::remove_reference_t<T>&& t) -> decltype(static_cast<typename transfer_cvref<T, U>::type&&>(t))
    {
        static_assert(!std::is_lvalue_reference_v<T>, "template argument substituting T is an lvalue reference type");
        return static_cast<typename transfer_cvref<T, U>::type&&>(t);
    }

    template <typename T>
    constexpr auto get_type_name()
    {
        if constexpr (trait::is_reflectable_v<T>) {
            return type_descriptor<T>::name;
        }
        else {
            return make_const_string("(unknown)");
        }
    }

} // namespace refl::detail

/********************************/
/*  Metadata-generation macros  */
/********************************/

#define REFL_DETAIL_STR_IMPL(...) #__VA_ARGS__
/** Used to stringify input separated by commas (e.g. template specializations with multiple types). */
#define REFL_DETAIL_STR(...) REFL_DETAIL_STR_IMPL(__VA_ARGS__)
/** Used to group input containing commas (e.g. template specializations with multiple types). */
#define REFL_DETAIL_GROUP(...) __VA_ARGS__

/**
 * Expands to the appropriate attributes static member variable.
 * DeclType must be the name of one of the constraints defined in attr::usage.
 * __VA_ARGS__ is the list of attributes.
 */
#define REFL_DETAIL_ATTRIBUTES(DeclType, ...) \
        static constexpr auto attributes{ ::refl::detail::make_attributes<::refl::attr::usage:: DeclType>(__VA_ARGS__) }; \

/**
 * Expands to the body of a type_info__ specialization.
 */
#define REFL_DETAIL_TYPE_BODY(TypeName, ...) \
        typedef REFL_DETAIL_GROUP TypeName type; \
        REFL_DETAIL_ATTRIBUTES(type, __VA_ARGS__) \
        static constexpr auto name{ ::refl::util::make_const_string(REFL_DETAIL_STR(REFL_DETAIL_GROUP TypeName)) }; \
        static constexpr size_t member_index_offset = __COUNTER__ + 1; \
        template <size_t, typename = void> \
        struct member {};

/**
 * Creates reflection information for a specified type. Takes an optional attribute list.
 * This macro must only be expanded in the global namespace.
 *
 * # Examples:
 * ```
 * REFL_TYPE(Point)
 * ...
 * REFL_END
 * ```
 */
#define REFL_TYPE(TypeName, ...) \
    namespace refl_impl::metadata { template<> struct type_info__<TypeName> { \
        REFL_DETAIL_TYPE_BODY((TypeName), __VA_ARGS__)

/**
 * Creates reflection information for a specified type template. Takes an optional attribute list.
 * TemplateDeclaration must be a panenthesis-enclosed list declaring the template parameters. (e.g. (typename A, typename B)).
 * TypeName must be the fully-specialized type name and should also be enclosed in panenthesis. (e.g. (MyType<A, B>))
 * This macro must only be expanded in the global namespace.
 *
 * # Examples:
 * ```
 * REFL_TEMPLATE((typename T), (std::vector<T>))
 * ...
 * REFL_END
 * ```
 */
#define REFL_TEMPLATE(TemplateDeclaration, TypeName, ...) \
    namespace refl_impl::metadata { template <REFL_DETAIL_GROUP TemplateDeclaration> struct type_info__<REFL_DETAIL_GROUP TypeName> { \
        REFL_DETAIL_TYPE_BODY(TypeName, __VA_ARGS__)

/**
 * Terminated the declaration of reflection metadata for a particular type.
 *
 * # Examples:
 * ```
 * REFL_TYPE(Point)
 * ...
 * REFL_END
 */
#define REFL_END \
        static constexpr size_t member_count{ __COUNTER__ - member_index_offset }; \
    }; }

#define REFL_DETAIL_MEMBER_HEADER template<typename Unused__> struct member<__COUNTER__ - member_index_offset, Unused__>

#define REFL_DETAIL_MEMBER_COMMON(MemberType_, MemberName_, ...) \
        typedef ::refl::member::MemberType_ member_type; \
        static constexpr auto name{ ::refl::util::make_const_string(REFL_DETAIL_STR(MemberName_)) }; \
        REFL_DETAIL_ATTRIBUTES(MemberType_, __VA_ARGS__)

/** Creates the support infrastructure needed for the refl::runtime::proxy type. */
/*
    There can be a total of 12 differently qualified member functions with the same name.
    Providing remaps for non-const and const-only strikes a balance between compilation time and usability.
    And even though there are many other remap implementation possibilities (like virtual, field variants),
    adding them was considered to not be efficient from a compilation-time point of view.
*/
#define REFL_DETAIL_MEMBER_PROXY(MemberName_) \
        template <typename Proxy> struct remap { \
            template <typename... Args> decltype(auto) MemberName_(Args&&... args) { \
                return Proxy::invoke_impl(static_cast<Proxy&>(*this), ::std::forward<Args>(args)...); \
            } \
            template <typename... Args> decltype(auto) MemberName_(Args&&... args) const { \
                return Proxy::invoke_impl(static_cast<const Proxy&>(*this), ::std::forward<Args>(args)...); \
            } \
        }

/**
 * Creates reflection information for a public field. Takes an optional attribute list.
 */
#define REFL_FIELD(FieldName_, ...) \
    REFL_DETAIL_MEMBER_HEADER { \
        REFL_DETAIL_MEMBER_COMMON(field, FieldName_, __VA_ARGS__) \
    public: \
        typedef decltype(type::FieldName_) value_type; \
        static constexpr auto pointer{ &type::FieldName_ }; \
        REFL_DETAIL_MEMBER_PROXY(FieldName_); \
    };

/**
 * Creates reflection information for a public functions. Takes an optional attribute list.
 */
#define REFL_FUNC(FunctionName_, ...) \
    REFL_DETAIL_MEMBER_HEADER { \
        REFL_DETAIL_MEMBER_COMMON(function, FunctionName_, __VA_ARGS__) \
        public: \
        template<typename Self, typename... Args> static constexpr auto invoke(Self&& self, Args&&... args) -> decltype(::refl::detail::forward_cast<Self, type>(self).FunctionName_(::std::forward<Args>(args)...)) {\
            return ::refl::detail::forward_cast<Self, type>(self).FunctionName_(::std::forward<Args>(args)...); \
        } \
        template<typename... Args> static constexpr auto invoke(Args&&... args) -> decltype(::refl::detail::head_t<type, Args...>::FunctionName_(::std::declval<Args>()...)) { \
            return ::refl::detail::head_t<type, Args...>::FunctionName_(::std::forward<Args>(args)...); \
        } \
        template <typename Dummy = void> \
        static constexpr auto pointer() -> decltype(&::refl::detail::head_t<type, Dummy>::FunctionName_) { return &::refl::detail::head_t<type, Dummy>::FunctionName_; } \
        template <typename Pointer> \
        static constexpr auto resolve() -> ::std::decay_t<decltype(Pointer(&type::FunctionName_))> { return Pointer(&type::FunctionName_); } \
        REFL_DETAIL_MEMBER_PROXY(FunctionName_); \
    };

/********************************/
/*  Default Reflection Metadata */
/********************************/

#define REFL_DETAIL_PRIMITIVE(TypeName) \
    REFL_TYPE(TypeName) \
    REFL_END

    // Char types.
    REFL_DETAIL_PRIMITIVE(char)
    REFL_DETAIL_PRIMITIVE(wchar_t)
    REFL_DETAIL_PRIMITIVE(char16_t)
    REFL_DETAIL_PRIMITIVE(char32_t)
#ifdef __cpp_lib_char8_t
    REFL_DETAIL_PRIMITIVE(char8_t)
#endif

    // Integral types.
    REFL_DETAIL_PRIMITIVE(bool)
    REFL_DETAIL_PRIMITIVE(signed char)
    REFL_DETAIL_PRIMITIVE(unsigned char)
    REFL_DETAIL_PRIMITIVE(signed short)
    REFL_DETAIL_PRIMITIVE(unsigned short)
    REFL_DETAIL_PRIMITIVE(signed int)
    REFL_DETAIL_PRIMITIVE(unsigned int)
    REFL_DETAIL_PRIMITIVE(signed long)
    REFL_DETAIL_PRIMITIVE(unsigned long)
    REFL_DETAIL_PRIMITIVE(signed long long)
    REFL_DETAIL_PRIMITIVE(unsigned long long)

    // Floating point types.
    REFL_DETAIL_PRIMITIVE(float)
    REFL_DETAIL_PRIMITIVE(double)
    REFL_DETAIL_PRIMITIVE(long double)

    // Other types.
    REFL_DETAIL_PRIMITIVE(decltype(nullptr))

    // Void type.
    REFL_TYPE(void)
    REFL_END

#undef REFL_DETAIL_PRIMITIVE

#define REFL_DETAIL_POINTER(Ptr) \
        template<typename T> \
        struct type_info__<T Ptr> { \
            typedef T Ptr type; \
            template <size_t N> \
            struct member {}; \
            static constexpr auto name{ ::refl::detail::get_type_name<T>() + ::refl::util::make_const_string(#Ptr) }; \
            static constexpr ::std::tuple<> attributes{ }; \
            static constexpr size_t member_count{ 0 }; \
        }

    namespace refl_impl
    {
        namespace metadata
        {
            REFL_DETAIL_POINTER(*);
            REFL_DETAIL_POINTER(&);
            REFL_DETAIL_POINTER(&&);
        }
    }

#undef REFL_DETAIL_POINTER

namespace refl::detail
{
    template <typename CharT>
    std::basic_string<CharT> convert(const std::string& str)
    {
        return std::basic_string<CharT>(str.begin(), str.end());
    }

#ifdef __cpp_lib_string_view
    struct write_basic_string_view
    {
        template <typename CharT, typename Traits>
        void operator()(std::basic_ostream<CharT>& os, std::basic_string_view<CharT, Traits> str) const
        {
            // some vers of clang dont have std::quoted(string_view) overload
            if (!str.back()) { // no copy needed when null-terminated
                os << std::quoted(str.data());
            }
            else {
                os << std::quoted(std::basic_string<CharT, Traits>(str.begin(), str.end()));
            }
        }
    };
#endif

    struct write_basic_string
    {
        template <typename CharT, typename Traits, typename Allocator>
        void operator()(std::basic_ostream<CharT>& os, const std::basic_string<CharT, Traits, Allocator>& str) const
        {
            os << std::quoted(str);
        }
    };

    struct write_exception
    {
        template <typename CharT>
        void operator()(std::basic_ostream<CharT>& os, const std::exception& e) const
        {
            os << convert<CharT>("Exception");
    #ifdef REFL_RTTI_ENABLED
            os << convert<CharT>(" (") << convert<CharT>(typeid(e).name()) << convert<CharT>(")");
    #endif
            os << convert<CharT>(": `") << e.what() << convert<CharT>("`");
        }
    };

    struct write_tuple
    {
        template <typename CharT, typename Tuple, size_t... Idx>
        void write(std::basic_ostream<CharT>& os, Tuple&& t, std::index_sequence<Idx...>) const
        {
            os << CharT('(');
            for_each(type_list<std::integral_constant<size_t, Idx>...>{}, [&](auto idx_c) {
                using idx_t = decltype(idx_c);
                runtime::debug(os, std::get<idx_t::value>(t));
                if constexpr (sizeof...(Idx) - 1 != idx_t::value) {
                    os << convert<CharT>(", ");
                }
            });
            os << CharT(')');
        }

        template <typename CharT, typename... Ts>
        void operator()(std::basic_ostream<CharT>& os, const std::tuple<Ts...>& t) const
        {
            write(os, t, std::make_index_sequence<sizeof...(Ts)>{});
        }
    };

    struct write_pair
    {
        template <typename CharT, typename K, typename V>
        void operator()(std::basic_ostream<CharT>& os, const std::pair<K, V>& t) const
        {
            os << CharT('(');
            runtime::debug(os, t.first);
            os << convert<CharT>(", ");
            runtime::debug(os, t.second);
            os << CharT(')');
        }
    };

    struct write_unique_ptr
    {
        template <typename CharT, typename T, typename D>
        void operator()(std::basic_ostream<CharT>& os, const std::unique_ptr<T, D>& t) const
        {
            runtime::debug(os, t.get(), true);
        }
    };

    struct write_shared_ptr
    {
        template <typename CharT, typename T>
        void operator()(std::basic_ostream<CharT>& os, const std::shared_ptr<T>& t) const
        {
            runtime::debug(os, t.get(), true);
        }
    };

    struct write_weak_ptr
    {
        template <typename CharT, typename T>
        void operator()(std::basic_ostream<CharT>& os, const std::weak_ptr<T>& t) const
        {
            runtime::debug(os, t.lock().get(), true);
        }
    };

    struct write_complex
    {
        template <typename CharT, typename T>
        void operator()(std::basic_ostream<CharT>& os, const std::complex<T>& t) const
        {
            runtime::debug(os, t.real());
            os << CharT('+');
            runtime::debug(os, t.imag());
            os << CharT('i');
        }
    };
} // namespace refl::detail

// Custom reflection information for
// some common built-in types (std::basic_string, std::tuple, std::pair).

#ifndef REFL_NO_STD_SUPPORT

REFL_TYPE(std::exception, debug{ refl::detail::write_exception() })
    REFL_FUNC(what, property{ })
REFL_END

REFL_TEMPLATE(
    (typename Elem, typename Traits, typename Alloc),
    (std::basic_string<Elem, Traits, Alloc>),
    debug{ refl::detail::write_basic_string() })
    REFL_FUNC(size, property{ })
    REFL_FUNC(data, property{ })
REFL_END

#ifdef __cpp_lib_string_view

REFL_TEMPLATE(
    (typename Elem, typename Traits),
    (std::basic_string_view<Elem, Traits>),
    debug{ refl::detail::write_basic_string_view() })
    REFL_FUNC(size, property{ })
    REFL_FUNC(data, property{ })
REFL_END

#endif

REFL_TEMPLATE(
    (typename... Ts),
    (std::tuple<Ts...>),
    debug{ refl::detail::write_tuple() })
REFL_END

REFL_TEMPLATE(
    (typename T, typename D),
    (std::unique_ptr<T, D>),
    debug{ refl::detail::write_unique_ptr() })
REFL_END

REFL_TEMPLATE(
    (typename T),
    (std::shared_ptr<T>),
    debug{ refl::detail::write_shared_ptr() })
REFL_END

REFL_TEMPLATE(
    (typename K, typename V),
    (std::pair<K, V>),
    debug{ refl::detail::write_pair() })
REFL_END

#ifndef REFL_NO_STD_COMPLEX

REFL_TEMPLATE(
    (typename T),
    (std::complex<T>),
    debug{ refl::detail::write_complex() })
REFL_END

#endif // !REFL_NO_STD_COMPLEX

#endif // !REFL_NO_STD_SUPPORT

#ifndef REFL_NO_AUTO_MACRO

#define REFL_DETAIL_EXPAND(x) x
#define REFL_DETAIL_FOR_EACH_0(...)
#define REFL_DETAIL_FOR_EACH_1(what, x, ...) what(x)
#define REFL_DETAIL_FOR_EACH_2(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_1(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_3(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_2(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_4(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_3(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_5(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_4(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_6(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_5(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_7(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_6(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_8(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_7(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_9(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_8(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_10(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_9(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_11(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_10(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_12(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_11(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_13(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_12(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_14(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_13(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_15(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_14(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_16(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_15(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_17(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_16(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_18(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_17(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_19(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_18(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_20(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_19(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_21(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_20(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_22(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_21(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_23(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_22(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_24(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_23(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_25(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_24(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_26(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_25(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_27(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_26(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_28(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_27(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_29(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_28(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_30(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_29(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_31(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_30(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_32(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_31(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_33(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_32(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_34(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_33(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_35(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_34(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_36(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_35(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_37(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_36(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_38(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_37(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_39(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_38(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_40(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_39(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_41(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_40(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_42(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_41(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_43(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_42(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_44(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_43(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_45(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_44(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_46(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_45(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_47(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_46(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_48(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_47(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_49(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_48(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_50(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_49(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_51(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_50(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_52(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_51(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_53(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_52(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_54(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_53(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_55(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_54(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_56(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_55(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_57(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_56(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_58(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_57(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_59(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_58(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_60(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_59(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_61(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_60(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_62(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_61(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_63(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_62(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_64(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_63(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_65(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_64(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_66(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_65(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_67(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_66(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_68(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_67(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_69(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_68(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_70(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_69(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_71(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_70(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_72(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_71(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_73(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_72(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_74(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_73(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_75(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_74(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_76(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_75(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_77(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_76(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_78(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_77(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_79(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_78(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_80(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_79(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_81(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_80(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_82(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_81(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_83(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_82(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_84(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_83(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_85(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_84(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_86(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_85(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_87(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_86(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_88(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_87(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_89(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_88(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_90(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_89(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_91(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_90(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_92(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_91(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_93(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_92(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_94(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_93(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_95(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_94(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_96(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_95(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_97(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_96(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_98(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_97(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_99(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_98(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_100(what, x, ...) what(x) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_99(what, __VA_ARGS__))

#define REFL_DETAIL_FOR_EACH_NARG(...) REFL_DETAIL_FOR_EACH_NARG_(__VA_ARGS__, REFL_DETAIL_FOR_EACH_RSEQ_N())
#define REFL_DETAIL_FOR_EACH_NARG_(...) REFL_DETAIL_EXPAND(REFL_DETAIL_FOR_EACH_ARG_N(__VA_ARGS__))
#define REFL_DETAIL_FOR_EACH_ARG_N(_1, _2, _3, _4, _5, _6, _7, _8, _9, _10, _11, _12, _13, _14, _15, _16, _17, _18, _19, _20, _21, _22, _23, _24, _25, _26, _27, _28, _29, _30, _31, _32, _33, _34, _35, _36, _37, _38, _39, _40, _41, _42, _43, _44, _45, _46, _47, _48, _49, _50, _51, _52, _53, _54, _55, _56, _57, _58, _59, _60, _61, _62, _63, _64, _65, _66, _67, _68, _69, _70, _71, _72, _73, _74, _75, _76, _77, _78, _79, _80, _81, _82, _83, _84, _85, _86, _87, _88, _89, _90, _91, _92, _93, _94, _95, _96, _97, _98, _99, _100, N, ...) N
#define REFL_DETAIL_FOR_EACH_RSEQ_N() 100, 99, 98, 97, 96, 95, 94, 93, 92, 91, 90, 89, 88, 87, 86, 85, 84, 83, 82, 81, 80, 79, 78, 77, 76, 75, 74, 73, 72, 71, 70, 69, 68, 67, 66, 65, 64, 63, 62, 61, 60, 59, 58, 57, 56, 55, 54, 53, 52, 51, 50, 49, 48, 47, 46, 45, 44, 43, 42, 41, 40, 39, 38, 37, 36, 35, 34, 33, 32, 31, 30, 29, 28, 27, 26, 25, 24, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0
#define REFL_DETAIL_CONCATENATE(x, y) x##y
#define REFL_DETAIL_FOR_EACH_(N, what, ...) REFL_DETAIL_EXPAND(REFL_DETAIL_CONCATENATE(REFL_DETAIL_FOR_EACH_, N)(what, __VA_ARGS__))
#define REFL_DETAIL_FOR_EACH(what, ...) REFL_DETAIL_FOR_EACH_(REFL_DETAIL_FOR_EACH_NARG(__VA_ARGS__), what, __VA_ARGS__)

// Intellisense does not work nicely with passing variadic parameters (for the attributes)
// through all of the macro expansions and causes differently named member declarations to be
// used during code inspection.
#ifdef __INTELLISENSE__

#define REFL_DETAIL_EX_1_type(X, ...) REFL_TYPE(X)
#define REFL_DETAIL_EX_1_template(X, Y, ...) REFL_TEMPLATE(X, Y)
#define REFL_DETAIL_EX_1_field(X, ...) REFL_FIELD(X)
#define REFL_DETAIL_EX_1_func(X, ...) REFL_FUNC(X)

#else // !defined(__INTELLISENSE__)

#define REFL_DETAIL_EX_1_type(...) REFL_DETAIL_EX_EXPAND(REFL_DETAIL_EX_DEFER(REFL_TYPE)(__VA_ARGS__))
#define REFL_DETAIL_EX_1_template(...) REFL_DETAIL_EX_EXPAND(REFL_DETAIL_EX_DEFER(REFL_TEMPLATE)(__VA_ARGS__))
#define REFL_DETAIL_EX_1_field(...) REFL_DETAIL_EX_EXPAND(REFL_DETAIL_EX_DEFER(REFL_FIELD)(__VA_ARGS__))
#define REFL_DETAIL_EX_1_func(...) REFL_DETAIL_EX_EXPAND(REFL_DETAIL_EX_DEFER(REFL_FUNC)(__VA_ARGS__))

#endif // __INTELLISENSE__

#define REFL_DETAIL_EX_(Specifier, ...) REFL_DETAIL_EX_1_##Specifier __VA_ARGS__

#define REFL_DETAIL_EX_EMPTY()
#define REFL_DETAIL_EX_DEFER(Id) Id REFL_DETAIL_EX_EMPTY()
#define REFL_DETAIL_EX_EXPAND(...)  __VA_ARGS__

#define REFL_DETAIL_EX_END() REFL_END

#define REFL_AUTO(...) REFL_DETAIL_FOR_EACH(REFL_DETAIL_EX_, __VA_ARGS__) REFL_DETAIL_EX_EXPAND(REFL_DETAIL_EX_DEFER(REFL_DETAIL_EX_END)())

#endif // !defined(REFL_NO_AUTO_MACRO)

#endif // REFL_INCLUDE_HPP