TheRock/rocm-libraries/shared/rocroller/lib/include/rocRoller/Serialization/HasTraits.hpp

// Copyright Advanced Micro Devices, Inc., or its affiliates.
// SPDX-License-Identifier: MIT

#pragma once

#include <rocRoller/Serialization/Base.hpp>

#include <cstddef>

namespace rocRoller
{
    namespace Serialization
    {
        template <typename T, T>
        struct SameType;

        template <typename T, typename IO, typename Context = EmptyContext>
        concept CMappedType = requires(T& obj, IO& io, Context& ctx)
        {
            {MappingTraits<T, IO, Context>::mapping(io, obj, ctx)};
        };

        template <typename T, typename IO, typename Context = EmptyContext>
        concept CEmptyMappedType = requires(T& obj, IO& io)
        {
            {MappingTraits<T, IO, Context>::mapping(io, obj)};
        };

        template <typename T, typename IO, typename Context = EmptyContext>
        struct has_MappingTraits
        {
            static const bool value = CMappedType<T, IO, Context>;
        };

        template <typename T, typename IO, typename Context = EmptyContext>
        struct has_EmptyMappingTraits
        {
            static const bool value
                = std::same_as<Context, EmptyContext> && CEmptyMappedType<T, IO, Context>;
        };

        template <typename T, typename IO, typename Context = EmptyContext>
        concept EmptyMappedType = has_EmptyMappingTraits<T, IO, Context>::
            value && !has_MappingTraits<T, IO, Context>::value;

        template <typename T, typename IO>
        class has_EnumTraits
        {
            using enumeration = void (*)(IO&, T&);

            template <typename U>
            static uint8_t test(SameType<enumeration, &U::enumeration>*);

            template <typename U>
            static uint32_t test(...);

        public:
            static const bool value = sizeof(test<EnumTraits<T, IO>>(nullptr)) == 1;
        };

        template <typename T, typename IO>
        concept EnumType = has_EnumTraits<T, IO>::value;

        template <typename T>
        concept CHasScalarTraits = requires(T const& cval, T& val, std::string const& string)
        {

            {
                ScalarTraits<T>::output(cval)
                } -> std::convertible_to<std::string>;

            {ScalarTraits<T>::input(string, val)};
        };

        template <typename T, typename IO>
        class has_SequenceTraits
        {
            using size = size_t (*)(IO&, T&);

            template <typename U>
            static uint8_t test(SameType<size, &U::size>*);

            template <typename u>
            static uint32_t test(...);

        public:
            static const bool value = sizeof(test<SequenceTraits<T, IO>>(nullptr)) == 1;
        };

        template <typename T, typename IO>
        concept SequenceType = has_SequenceTraits<T, IO>::value;

        template <typename T, typename IO>
        class has_CustomMappingTraits
        {
            using inputOne = void (*)(IO&, std::string const&, T&);
            using output   = void (*)(IO&, T&);

            template <typename U>
            static uint8_t test(SameType<inputOne, &U::inputOne>*, SameType<output, &U::output>*);

            template <typename u>
            static uint32_t test(...);

        public:
            static const bool value
                = sizeof(test<CustomMappingTraits<T, IO>>(nullptr, nullptr)) == 1;
        };

        template <typename T, typename IO>
        concept CustomMappingType = has_CustomMappingTraits<T, IO>::value;

        template <typename T, typename IO>
        struct has_SerializationTraits
        {
            static const bool value0
                = has_EmptyMappingTraits<T, IO>::value || has_MappingTraits<T, IO>::value;
            static const bool value1 = has_EnumTraits<T, IO>::value;
            static const bool value2 = has_SequenceTraits<T, IO>::value;
            static const bool value3 = has_CustomMappingTraits<T, IO>::value;
            static const bool value4 = CHasScalarTraits<T>;

            static const int count = value0 + value1 + value2 + value3 + value4;

            static_assert(count == 0 || count == 1, "Ambiguous serialization!");

            static const bool value = value0 || value1 || value2 || value3 || value4;
        };

        template <typename T, typename IO, typename Context = EmptyContext>
        concept SerializableType = has_SerializationTraits<T, IO>::value;

        template <typename T, typename IO, typename Context = EmptyContext>
        concept ValueType = !has_SerializationTraits<T, IO>::value;

        template <typename T>
        concept CHasFlowMember = requires
        {
            // clang-format off
            { T::flow } -> std::convertible_to<bool>;
            // clang-format on
        };

        template <typename T>
        struct HasFlowValue
        {
            static const bool flow = false;
        };

        template <CHasFlowMember T>
        struct HasFlowValue<T>
        {
            static const bool flow = T::flow;
        };

        /**
         * Concept that will match a type that has a static `flow` member which is true. It will
         * not match a type that has no such member, nor will it match if that member is set to
         * false. It will also not cause an error if it's tested against a type that has no such
         * member.
         */
        template <typename T>
        concept CHasFlow = HasFlowValue<T>::flow;

    } // namespace Serialization
} // namespace rocRoller