cpphibernate/include/cpphibernate/modifier/modifiers.inl

#pragma once

#include "modifier.h"
#include "modifiers.h"

namespace cpphibernate
{

    namespace __impl
    {

        /* modifiers_t */

        template<typename... T_modifiers>
        using modifiers_t = hana::basic_tuple<T_modifiers...>;

        /* modifiers_builder */

        template<typename T, typename>
        struct modifiers_builder
        {
            template<typename... T_args>
            static constexpr decltype(auto) apply(T_args&&...)
                { static_assert(sizeof...(T_args) == -1, "Invalid parameters for make_modifiers(...)!"); }
        };

        template<typename... T_args>
        struct modifiers_builder<
            mp::list<T_args...>,
            mp::enable_if_t<
                mp::is_true_v<is_modifier_v<mp::decay_t<T_args>>...>>>
        {
            static constexpr decltype(auto) apply(T_args&&... args)
            {
                using modifiers_type = modifiers_t<T_args...>;
                return modifiers_type(std::forward<T_args>(args)...);
            }
        };

        /* is_modifiers_impl */

        template<typename T, typename = void>
        struct is_modifiers_impl
            : mp::false_t
            { };

        template<typename... T>
        struct is_modifiers_impl<
            modifiers_t<T...>,
            mp::enable_if_t<mp::is_true_v<is_modifier_v<mp::decay_t<T>>...>>>
            : mp::true_t
            { };

    }

    /* is_modifiers */

    template<typename T>
    struct is_modifiers
        : public __impl::is_modifiers_impl<T>
        { };

}