daw_json_parse_common.h

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// Copyright (c) Darrell Wright
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE or copy at http://www.boost.org/LICENSE_1_0.txt)
//
// Official repository: https://github.com/beached/daw_json_link
//
 
#pragma once
 
#include "daw/json/impl/version.h"
 
#include "daw/json/impl/daw_json_assert.h"
#include "daw/json/impl/daw_json_enums.h"
#include "daw/json/impl/daw_json_exec_modes.h"
#include "daw/json/impl/daw_json_link_types_aggregate.h"
#include "daw/json/impl/daw_json_name.h"
#include "daw/json/impl/daw_json_option_bits.h"
#include "daw/json/impl/daw_json_traits.h"
#include "daw/json/impl/daw_json_type_options.h"
#include "daw/json/impl/daw_json_value_fwd.h"
 
#include <daw/cpp_17.h>
#include <daw/daw_allocator_construct.h>
#include <daw/daw_arith_traits.h>
#include <daw/daw_callable.h>
#include <daw/daw_cpp20_concept.h>
#include <daw/daw_cpp_feature_check.h>
#include <daw/daw_enable_requires.h>
#include <daw/daw_fwd_pack_apply.h>
#include <daw/daw_move.h>
#include <daw/daw_scope_guard.h>
#include <daw/daw_string_view.h>
#include <daw/daw_traits.h>
#include <daw/json/concepts/daw_container_traits.h>
 
#include <array>
#include <cstddef>
#include <iterator>
#include <optional>
#include <string>
#include <string_view>
#include <vector>
 
namespace daw::json {
  inline namespace DAW_JSON_VER {
    namespace json_details {
      DAW_MAKE_REQ_TRAIT_TYPE( is_json_member_list_v,
                               T::i_am_a_json_member_list );
 
      template<typename T>
      using ordered_member_subtype_test = typename T::json_member;
 
      template<typename T>
      using ordered_member_subtype_t =
        typename daw::detected_or_t<T, ordered_member_subtype_test, T>;
 
      template<typename T, typename Default>
      inline constexpr auto json_class_constructor =
        json_class_constructor_t<T, Default>{ };
 
      template<typename Value, typename Constructor, typename ParseState,
               typename... Args>
      DAW_ATTRIB_INLINE static constexpr auto
      construct_value( ParseState &parse_state, Args &&...args ) {
        // Silence MSVC warning, used in other if constexpr case
        (void)parse_state;
        if constexpr( ParseState::has_allocator ) {
          auto alloc = parse_state.template get_allocator_for<Value>( );
          return daw::try_alloc_construct<Value, Constructor>(
            std::move( alloc ), DAW_FWD( args )... );
        } else {
          static_assert(
            daw::is_callable_v<Constructor, Args...>,
            "Unable to construct value with the supplied arguments" );
          return Constructor{ }( DAW_FWD( args )... );
        }
      }
 
#if not defined( DAW_JSON_USE_GENERIC_LAMBDAS )
      template<typename Constructor>
      struct construct_value_tp_invoke_t {
        template<typename... TArgs, std::size_t... Is>
        DAW_ATTRIB_INLINE constexpr auto
        operator( )( fwd_pack<TArgs...> &&tp,
                     std::index_sequence<Is...> ) const {
          return Constructor{ }( get<Is>( std::move( tp ) )... );
        }
 
        template<typename... TArgs, typename Allocator, std::size_t... Is>
        DAW_ATTRIB_INLINE constexpr auto
        operator( )( fwd_pack<TArgs...> &&tp, Allocator &alloc,
                     std::index_sequence<Is...> ) const {
          return Constructor{ }( get<Is>( std::move( tp ) )...,
                                 DAW_FWD( alloc ) );
        }
 
        template<typename Alloc, typename... TArgs, std::size_t... Is>
        DAW_ATTRIB_INLINE constexpr auto
        operator( )( std::allocator_arg_t, Alloc &&alloc,
                     fwd_pack<TArgs...> &&tp,
                     std::index_sequence<Is...> ) const {
 
          return Constructor{ }( std::allocator_arg,
                                 DAW_FWD( alloc ),
                                 get<Is>( std::move( tp ) )... );
        }
      };
      template<typename Constructor>
      inline constexpr auto construct_value_tp_invoke =
        construct_value_tp_invoke_t<Constructor>{ };
#endif
 
      template<typename Value, typename Constructor, typename ParseState,
               typename... Args>
      DAW_ATTRIB_FLATINLINE static constexpr auto
      construct_value_tp( ParseState &parse_state,
                          fwd_pack<Args...> &&tp_args ) {
 
#if defined( DAW_JSON_USE_GENERIC_LAMBDAS )
        if constexpr( ParseState::has_allocator ) {
          // ParseState has a user allocator, pass that if we can to the
          // constructed value
          using alloc_t =
            typename ParseState::template allocator_type_as<Value>;
          auto alloc = parse_state.template get_allocator_for<Value>( );
          // There are several ways that the allocator is passed on
          if constexpr( daw::is_callable_v<Constructor, Args..., alloc_t> ) {
            return [&]<std::size_t... Is>( std::index_sequence<Is...> ) {
              // Type( args..., alloc )
              return Constructor{ }( get<Is>( std::move( tp_args ) )...,
                                     std::move( alloc ) );
            }( std::make_index_sequence<sizeof...( Args )>{ } );
          } else if constexpr( daw::is_callable_v<Constructor,
                                                  std::allocator_arg_t,
                                                  alloc_t,
                                                  Args...> ) {
            // Type( std::allocator_arg, alloc, args... )
            return [&]<std::size_t... Is>( std::index_sequence<Is...> ) {
              return Constructor{ }( std::allocator_arg,
                                     std::move( alloc ),
                                     get<Is>( std::move( tp_args ) )... );
            }( std::make_index_sequence<sizeof...( Args )>{ } );
          } else {
            // This type does not take a known allocator in the constructor,
            // fallback to normal construction
            // Type( args... )
            static_assert(
              daw::is_callable_v<Constructor, Args...>,
              "Unable to construct value with the supplied arguments" );
            return [&]<std::size_t... Is>( std::index_sequence<Is...> ) {
              return Constructor{ }( get<Is>( std::move( tp_args ) )... );
            }( std::make_index_sequence<sizeof...( Args )>{ } );
          }
        } else {
          // Type( args... )
          // No ParseState user allocator
          // Silence MSVC warning, used in other if constexpr case
          (void)parse_state;
          static_assert(
            daw::is_callable_v<Constructor, Args...>,
            "Unable to construct value with the supplied arguments" );
          return [&]<std::size_t... Is>( std::index_sequence<Is...> ) {
            return Constructor{ }( get<Is>( std::move( tp_args ) )... );
          }( std::make_index_sequence<sizeof...( Args )>{ } );
        }
#else
        if constexpr( ParseState::has_allocator ) {
          // ParseState has a user allocator, pass that if we can to the
          // constructed value
          using alloc_t =
            typename ParseState::template allocator_type_as<Value>;
          auto alloc = parse_state.template get_allocator_for<Value>( );
          if constexpr( daw::is_callable_v<Constructor, Args..., alloc_t> ) {
            // Type( args..., alloc )
            return construct_value_tp_invoke<Constructor>(
              std::move( tp_args ),
              std::move( alloc ),
              std::index_sequence_for<Args...>{ } );
          } else if constexpr( daw::is_callable_v<Constructor,
                                                  std::allocator_arg_t,
                                                  alloc_t,
                                                  Args...> ) {
            // Type( std::allocator_arg, alloc, args... )
            return construct_value_tp_invoke<Constructor>(
              std::allocator_arg,
              std::move( alloc ),
              std::move( tp_args ),
              std::index_sequence_for<Args...>{ } );
          } else {
            // This type does not take a known allocator in the constructor,
            // fallback to normal construction
            // Type( args... )
            static_assert(
              daw::is_callable_v<Constructor, Args...>,
              "Unable to construct value with the supplied arguments" );
            return construct_value_tp_invoke<Constructor>(
              std::move( tp_args ), std::index_sequence_for<Args...>{ } );
          }
        } else {
          // No ParseState user allocator
          // Silence MSVC warning, used in other if constexpr case
          // Type( args... )
          (void)parse_state;
          static_assert(
            daw::is_callable_v<Constructor, Args...>,
            "Unable to construct value with the supplied arguments" );
          return construct_value_tp_invoke<Constructor>(
            std::move( tp_args ), std::index_sequence_for<Args...>{ } );
        }
#endif
      }
 
      template<typename T>
      DAW_CPP20_CONCEPT has_json_data_contract_trait_v =
        not std::is_same_v<missing_json_data_contract_for_or_unknown_type<T>,
                           json_data_contract_trait_t<T>>;
 
      DAW_JSON_MAKE_REQ_TRAIT(
        has_json_to_json_data_v,
        json_data_contract<T>::to_json_data( std::declval<T &>( ) ) );
 
      DAW_JSON_MAKE_REQ_TYPE_ALIAS_TRAIT(
        is_submember_tagged_variant_v,
        json_data_contract<T>::type::i_am_a_submember_tagged_variant );
 
      template<typename T>
      using json_nullable_member_type_t = typename T::member_type;
 
      /***
       * Helpers to set options on json_ types
       */
 
      template<json_options_t CurrentOptions, auto option, auto... options>
      inline constexpr json_options_t number_opts_set =
        set_bits( number_opts, CurrentOptions, option, options... );
 
      template<json_options_t CurrentOptions, auto option, auto... options>
      inline constexpr json_options_t bool_opts_set =
        set_bits( bool_opts, CurrentOptions, option, options... );
 
      template<json_options_t CurrentOptions, auto option, auto... options>
      inline constexpr json_options_t string_opts_set =
        set_bits( string_opts, CurrentOptions, option, options... );
 
      template<json_options_t CurrentOptions, auto option, auto... options>
      inline constexpr json_options_t string_raw_opts_set =
        set_bits( string_raw_opts, CurrentOptions, option, options... );
 
      template<json_options_t CurrentOptions, auto option, auto... options>
      inline constexpr json_options_t json_custom_opts_set =
        set_bits( json_custom_opts, CurrentOptions, option, options... );
 
      /*
      template<json_options_t CurrentOptions, auto option, auto... options>
      inline constexpr json_options_t tuple_opts_set =
        set_bits( tuple_opts, CurrentOptions, option, options... );
        */
    } // namespace json_details
 
    namespace json_base {
      template<typename T, typename JsonMember = use_default,
               JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      struct json_nullable;
 
    } // namespace json_base
    namespace json_details {
      template<typename T>
      inline constexpr bool is_json_nullable_v = false;
 
      template<typename T, typename JsonMember, JsonNullable NullableType,
               typename Constructor>
      inline constexpr bool is_json_nullable_v<
        json_base::json_nullable<T, JsonMember, NullableType, Constructor>> =
        true;
 
      template<typename T>
      struct json_empty_class {
        static_assert( std::is_empty_v<T>, "T is expected to empty" );
        using i_am_a_json_type = void;
        using i_am_a_deduced_empty_class = void;
        using wrapped_type = T;
 
        using constructor_t = default_constructor<T>;
        using parse_to_t = T;
 
        static constexpr auto expected_type = JsonParseTypes::Class;
        static constexpr auto underlying_json_type = JsonBaseParseTypes::Class;
      };
 
      template<typename T>
      struct json_ordered_class {
        static_assert( can_convert_to_tuple_v<T>, "T is expected to empty" );
        using i_am_a_json_type = void;
        using i_am_a_deduced_ordered_class = void;
        using wrapped_type = T;
 
        using constructor_t = default_constructor<T>;
        using parse_to_t = T;
 
        static constexpr auto expected_type = JsonParseTypes::Tuple;
 
        static constexpr auto underlying_json_type = JsonBaseParseTypes::Class;
      };
    } // namespace json_details
 
    namespace json_base {
 
      template<typename T, typename Constructor = use_default>
      struct json_class;
 
      template<typename T, JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_class_null =
        json_nullable<T, json_class<json_details::unwrapped_t<T>>, NullableType,
                      Constructor>;
 
      template<typename JsonElement, typename Container = use_default,
               typename Constructor = use_default>
      struct json_array;
 
      template<typename T, typename FromJsonConverter = use_default,
               typename ToJsonConverter = use_default,
               json_options_t Options = json_custom_opts_def>
      struct json_custom;
 
      template<typename Variant, typename JsonElements = use_default,
               typename Constructor = use_default>
      struct json_variant;
 
      template<typename T, typename TagMember, typename Switcher,
               typename JsonElements = use_default,
               typename Constructor = use_default>
      struct json_tagged_variant;
 
      template<typename T, json_options_t Options = string_raw_opts_def,
               typename Constructor = use_default>
      struct json_string_raw;
 
      template<typename T, json_options_t Options = string_raw_opts_def,
               JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_string_raw_null =
        json_nullable<T, json_string_raw<json_details::unwrapped_t<T>, Options>,
                      NullableType, Constructor>;
 
      template<typename T, json_options_t Options = string_opts_def,
               typename Constructor = use_default>
      struct json_string;
 
      template<typename T, json_options_t Options = string_opts_def,
               JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_string_null =
        json_nullable<T, json_string<json_details::unwrapped_t<T>, Options>,
                      NullableType, Constructor>;
 
      template<typename T, json_options_t Options = bool_opts_def,
               typename Constructor = use_default>
      struct json_bool;
 
      template<typename T, json_options_t Options = bool_opts_def,
               JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_bool_null =
        json_nullable<T, json_bool<json_details::unwrapped_t<T>, Options>,
                      NullableType, Constructor>;
 
      template<typename T, typename Constructor = use_default>
      struct json_date;
 
      template<typename T, json_options_t Options = number_opts_def,
               typename Constructor = use_default>
      struct json_number;
 
      template<typename T, json_options_t Options = number_opts_def,
               JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_number_null =
        json_nullable<T, json_number<json_details::unwrapped_t<T>, Options>,
                      NullableType, Constructor>;
 
      template<typename Container, typename JsonValueType = use_default,
               typename JsonKeyType = use_default,
               typename Constructor = use_default>
      struct json_key_value;
 
      template<typename Container, typename JsonValueType = use_default,
               typename JsonKeyType = use_default,
               typename Constructor = use_default>
      struct json_key_value_array;
 
      template<typename Container, typename JsonValueType, typename JsonKeyType,
               JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_key_value_null =
        json_nullable<Container,
                      json_key_value<json_details::unwrapped_t<Container>,
                                     JsonValueType, JsonKeyType>,
                      NullableType, Constructor>;
 
      template<typename Tuple, typename JsonTupleTypesList = use_default,
               typename Constructor = use_default>
      struct json_tuple;
 
      template<typename Tuple, typename JsonTupleTypesList = use_default,
               JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_tuple_null = json_nullable<
        Tuple, json_tuple<json_details::unwrapped_t<Tuple>, JsonTupleTypesList>,
        NullableType, Constructor>;
 
      /***
       * json_raw allows for raw JSON access to the member data. It requires a
       * type that is constructable from (char const *, std::size_t) arguments
       * and for serialization requires that it can be passed to
       * std::begin/std::end and the iterator returned has a value_type of char
       * @tparam T type to hold raw JSON data, defaults to json_value
       * @tparam Constructor A callable used to construct T.
       */
      template<typename T, typename Constructor = use_default>
      struct json_raw;
 
      /***
       * json_raw_null allows for raw JSON access to the nullable member data.
       * It requires a type that is constructable from (char const *,
       * std::size_t) arguments and for serialization requires that it can be
       * passed to std::begin/std::end and the iterator returned has a
       * value_type of char
       * @tparam T type to hold raw JSON data, defaults to json_value
       * @tparam Constructor A callable used to construct T.
       */
      template<typename T, JsonNullable NullableType = JsonNullable::Nullable,
               typename Constructor = use_default>
      using json_raw_null =
        json_nullable<T, json_raw<json_details::unwrapped_t<T>>, NullableType,
                      Constructor>;
    } // namespace json_base
 
    namespace json_details {
      template<typename T>
      DAW_ATTRIB_INLINE DAW_CONSTEVAL JsonParseTypes
      number_parse_type_impl_test( ) {
        if constexpr( daw::is_floating_point_v<T> ) {
          return JsonParseTypes::Real;
        } else if constexpr( daw::is_signed_v<T> ) {
          return JsonParseTypes::Signed;
        } else {
          static_assert( daw::is_unsigned_v<T> );
          return JsonParseTypes::Unsigned;
        }
      }
 
      template<typename T>
      DAW_ATTRIB_INLINE DAW_CONSTEVAL JsonParseTypes number_parse_type_test( ) {
        if constexpr( std::is_enum_v<T> ) {
          return number_parse_type_impl_test<std::underlying_type_t<T>>( );
        } else {
          return number_parse_type_impl_test<T>( );
        }
      }
 
      template<typename T>
      inline constexpr JsonParseTypes number_parse_type_v =
        number_parse_type_test<T>( );
 
      template<typename, typename = void>
      struct json_deduced_type_map {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::Unknown;
 
        static constexpr bool type_map_found = false;
      };
 
      template<typename JsonType>
      DAW_REQUIRES( is_a_json_type_v<JsonType> )
      struct json_deduced_type_map<
        JsonType DAW_ENABLEIF_S( is_a_json_type_v<JsonType> )> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::Unknown;
 
        using type = JsonType;
        static constexpr bool type_map_found = true;
      };
 
      template<typename T>
      DAW_REQUIRES( has_json_data_contract_trait_v<T> )
      struct json_deduced_type_map<
        T DAW_ENABLEIF_S( has_json_data_contract_trait_v<T> )> {
        static constexpr bool is_null = false;
        using type = typename json_data_contract<T>::type;
        static_assert( is_json_member_list_v<type>,
                       "Expected a JSON member list" );
        static constexpr auto parse_type = JsonParseTypes::Unknown;
 
        static constexpr bool type_map_found = true;
      };
 
      template<>
      struct json_deduced_type_map<daw::string_view> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::StringRaw;
 
        static constexpr bool type_map_found = true;
      };
 
      template<>
      struct json_deduced_type_map<std::string_view> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::StringRaw;
 
        static constexpr bool type_map_found = true;
      };
 
      template<>
      struct json_deduced_type_map<std::string> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::StringEscaped;
 
        static constexpr bool type_map_found = true;
      };
 
      template<>
      struct json_deduced_type_map<bool> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::Bool;
        static constexpr bool type_map_found = true;
      };
 
      // libc++ has a non-conforming vector<bool>::const_reference as it isn't
      // bool https://bugs.llvm.org/show_bug.cgi?id=16077
#if defined( _LIBCPP_VERSION )
      template<>
      struct json_deduced_type_map<
        typename std::vector<bool>::const_reference> {
 
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::Bool;
 
        static constexpr bool type_map_found = true;
      };
#endif
 
      template<typename Integer>
      DAW_REQUIRES(
        not json_details::has_json_data_contract_trait_v<Integer> and
        daw::is_integral_v<Integer> )
      struct json_deduced_type_map<Integer DAW_ENABLEIF_S(
        not json_details::has_json_data_contract_trait_v<Integer> and
        daw::is_integral_v<Integer> )> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = daw::is_signed_v<Integer>
                                             ? JsonParseTypes::Signed
                                             : JsonParseTypes::Unsigned;
 
        static constexpr bool type_map_found = true;
      };
 
      template<typename Enum>
      DAW_REQUIRES( not json_details::has_json_data_contract_trait_v<Enum> and
                    std::is_enum_v<Enum> )
      struct json_deduced_type_map<Enum DAW_ENABLEIF_S(
        not json_details::has_json_data_contract_trait_v<Enum> and
        std::is_enum_v<Enum> )> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type =
          daw::is_signed_v<std::underlying_type<Enum>>
            ? JsonParseTypes::Signed
            : JsonParseTypes::Unsigned;
 
        static constexpr bool type_map_found = true;
      };
 
      template<typename FloatingPoint>
      DAW_REQUIRES(
        not json_details::has_json_data_contract_trait_v<FloatingPoint> and
        daw::is_floating_point_v<FloatingPoint> )
      struct json_deduced_type_map<FloatingPoint DAW_ENABLEIF_S(
        not json_details::has_json_data_contract_trait_v<FloatingPoint> and
        daw::is_floating_point_v<FloatingPoint> )> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::Real;
 
        static constexpr bool type_map_found = true;
      };
 
      template<typename Tuple>
      DAW_REQUIRES( not json_details::has_json_data_contract_trait_v<Tuple> and
                    is_tuple_v<Tuple> )
      struct json_deduced_type_map<Tuple DAW_ENABLEIF_S(
        not json_details::has_json_data_contract_trait_v<Tuple> and
        is_tuple_v<Tuple> )> {
        static constexpr bool is_null = false;
        static constexpr auto parse_type = JsonParseTypes::Tuple;
 
        static constexpr bool type_map_found = true;
      };
 
      namespace container_detect {
        template<typename T>
        using is_string_test =
          decltype( (void)( std::begin( std::declval<T &>( ) ) ),
                    (void)( std::end( std::declval<T &>( ) ) ),
                    std::declval<typename T::value_type>( ) );
      } // namespace container_detect
 
      template<typename String>
      DAW_CPP20_CONCEPT is_string_v = std::is_convertible_v<
        char, daw::detected_t<container_detect::is_string_test, String>>;
 
      DAW_JSON_MAKE_REQ_TRAIT(
        is_associative_container_v,
        ( (void)( std::begin( std::declval<T &>( ) ) ),
          (void)( std::end( std::declval<T &>( ) ) ),
          (void)( std::declval<typename T::value_type>( ) ),
          (void)( std::declval<typename T::key_type>( ) ),
          (void)( std::declval<typename T::mapped_type>( ) ) ) );
 
      template<typename AssociativeContainer>
      DAW_REQUIRES( not has_json_data_contract_trait_v<AssociativeContainer> and
                    is_associative_container_v<AssociativeContainer> )
      struct json_deduced_type_map<AssociativeContainer DAW_ENABLEIF_S(
        not has_json_data_contract_trait_v<AssociativeContainer> and
        is_associative_container_v<AssociativeContainer> )> {
        static constexpr bool is_null = false;
        using key = typename AssociativeContainer::key_type;
        using value = typename AssociativeContainer::mapped_type;
        static constexpr auto parse_type = JsonParseTypes::KeyValue;
 
        static constexpr bool type_map_found = true;
      };
 
      template<typename T>
      DAW_CPP20_CONCEPT is_deduced_array_v =
        not has_json_data_contract_trait_v<T> and
        not is_associative_container_v<T> and concepts::is_container_v<T> and
        not is_string_v<T>;
 
      template<typename Container>
      DAW_REQUIRES( is_deduced_array_v<Container> )
      struct json_deduced_type_map<
        Container DAW_ENABLEIF_S( is_deduced_array_v<Container> )> {
        static constexpr bool is_null = false;
        using value = typename Container::value_type;
        static constexpr auto parse_type = JsonParseTypes::Array;
 
        static constexpr bool type_map_found = true;
      };
 
      template<typename T>
      DAW_CPP20_CONCEPT has_nullable_type_map_v =
        concepts::is_nullable_value_v<T> and
        not has_json_data_contract_trait_v<T> and
        daw::is_detected_v<json_deduced_type_map,
                           concepts::nullable_value_type_t<T>>;
 
      template<typename T>
      DAW_REQUIRES( has_nullable_type_map_v<T> )
      struct json_deduced_type_map<
        T DAW_ENABLEIF_S( has_nullable_type_map_v<T> )> {
        static constexpr bool is_null = true;
        using sub_type = concepts::nullable_value_type_t<T>;
        using type = json_deduced_type_map<sub_type>;
        static constexpr auto parse_type = type::parse_type;
        static constexpr bool type_map_found = true;
      };
 
      template<typename T>
      DAW_CPP20_CONCEPT has_deduced_type_mapping_v =
        json_deduced_type_map<T>::type_map_found;
 
      template<typename... Ts>
      DAW_CPP20_CONCEPT are_deduced_type_mapped_v =
        ( has_deduced_type_mapping_v<Ts> and ... );
 
      template<typename Mapped, bool Found = true>
      struct json_link_quick_map_type {
        static constexpr bool value = Found;
        using mapped_type = Mapped;
      };
 
      template<JsonParseTypes Value>
      DAW_CPP20_CONCEPT is_arithmetic_parse_type_v =
        daw::traits::equal_to_any_of_v<Value, JsonParseTypes::Signed,
                                       JsonParseTypes::Unsigned,
                                       JsonParseTypes::Real>;
 
      template<typename T>
      DAW_ATTRIB_INLINE DAW_CONSTEVAL auto json_link_quick_map( ) noexcept {
        if constexpr( is_a_json_type_v<T> ) {
          return json_link_quick_map_type<T>{ };
        } else if constexpr( has_deduced_type_mapping_v<T> ) {
          using mapped_type_t = json_deduced_type_map<T>;
          using parse_type = daw::constant<mapped_type_t::parse_type>;
          using is_null = daw::constant<mapped_type_t::is_null>;
          if constexpr( parse_type::value == JsonParseTypes::Unknown ) {
            if constexpr( is_null::value ) {
              if constexpr( has_json_data_contract_trait_v<
                              typename mapped_type_t::sub_type> ) {
                return json_link_quick_map_type<
                  json_base::json_class_null<T>>{ };
              } else {
                return json_link_quick_map_type<json_base::json_raw_null<T>>{ };
              }
            } else {
              return json_link_quick_map_type<json_base::json_raw<T>>{ };
            }
          } else if constexpr( parse_type::value ==
                               JsonParseTypes::StringRaw ) {
            if constexpr( is_null::value ) {
              return json_link_quick_map_type<
                json_base::json_string_raw_null<T>>{ };
            } else {
              return json_link_quick_map_type<json_base::json_string_raw<T>>{ };
            }
          } else if constexpr( parse_type::value ==
                               JsonParseTypes::StringEscaped ) {
            if constexpr( is_null::value ) {
              return json_link_quick_map_type<
                json_base::json_string_null<T>>{ };
            } else {
              return json_link_quick_map_type<json_base::json_string<T>>{ };
            }
          } else if constexpr( parse_type::value == JsonParseTypes::Bool ) {
            if constexpr( is_null::value ) {
              return json_link_quick_map_type<json_base::json_bool_null<T>>{ };
            } else {
              return json_link_quick_map_type<json_base::json_bool<T>>{ };
            }
          } else if constexpr( is_arithmetic_parse_type_v<parse_type::value> ) {
            if constexpr( is_null::value ) {
              return json_link_quick_map_type<
                json_base::json_number_null<T>>{ };
            } else {
              return json_link_quick_map_type<json_base::json_number<T>>{ };
            }
          } else if constexpr( parse_type::value == JsonParseTypes::Tuple ) {
            if constexpr( is_null::value ) {
              return json_link_quick_map_type<json_base::json_tuple_null<T>>{ };
            } else {
              return json_link_quick_map_type<json_base::json_tuple<T>>{ };
            }
          } else if constexpr( parse_type::value == JsonParseTypes::KeyValue ) {
            if constexpr( is_null::value ) {
              using b_t = json_base_type_t<mapped_type_t>;
              using k_t = typename b_t::key;
              using v_t = typename b_t::value;
              return json_link_quick_map_type<
                json_base::json_key_value_null<T, v_t, k_t>>{ };
            } else {
              using k_t = typename mapped_type_t::key;
              using v_t = typename mapped_type_t::value;
              return json_link_quick_map_type<
                json_base::json_key_value<T, v_t, k_t>>{ };
            }
          } else if constexpr( parse_type::value == JsonParseTypes::Array ) {
            if constexpr( is_null::value ) {
              using b_t = json_base_type_t<mapped_type_t>;
              using v_t = typename b_t::value;
              return json_link_quick_map_type<
                json_base::json_nullable<T, json_base::json_array<v_t, T>>>{ };
            } else {
              using v_t = typename mapped_type_t::value;
              return json_link_quick_map_type<json_base::json_array<v_t, T>>{ };
            }
          } else {
            return json_link_quick_map_type<void, false>{ };
          }
        } else {
          return json_link_quick_map_type<void, false>{ };
        }
      }
 
      template<typename T>
      DAW_CPP20_CONCEPT has_json_link_quick_map_v =
        decltype( json_link_quick_map<T>( ) )::value;
 
      template<typename T>
      using json_link_quick_map_t =
        typename decltype( json_link_quick_map<T>( ) )::mapped_type;
 
      template<typename JsonType>
      struct json_class_map_type {
        using type = typename json_data_contract_trait_t<JsonType>::json_member;
      };
 
      template<typename>
      struct is_json_class_map : std::false_type {};
 
      // This maybe specialized
      template<typename T>
      inline constexpr bool is_json_class_map_v =
        has_json_data_contract_trait_v<T> and
        is_json_class_map_v<json_data_contract_trait_t<T>>;
 
      template<typename T>
      DAW_ATTRIB_INLINE DAW_CONSTEVAL auto json_deduced_type_impl( ) noexcept {
        if constexpr( is_a_basic_json_value<T> ) {
          return daw::traits::identity<json_base::json_raw<T>>{ };
        } else if constexpr( is_an_ordered_member_v<T> ) {
          using type = T;
          return daw::traits::identity<type>{ };
        } else if constexpr( has_json_data_contract_trait_v<T> ) {
          static_assert( not std::is_same_v<T, void> );
 
          using type = json_base::json_class<T>;
 
          static_assert( not std::is_same_v<daw::remove_cvref_t<type>, void>,
                         "Detection failure" );
          static_assert( not is_nonesuch_v<remove_cvref_t<type>>,
                         "Detection failure" );
          return daw::traits::identity<type>{ };
        } else if constexpr( has_json_link_quick_map_v<T> ) {
          static_assert( not std::is_same_v<T, void> );
          using type = json_link_quick_map_t<T>;
          using rcvref_type = remove_cvref_t<type>;
          static_assert( not std::is_same_v<rcvref_type, void>,
                         "Detection failure" );
          static_assert( not is_nonesuch_v<rcvref_type>, "Detection failure" );
          return daw::traits::identity<type>{ };
        } else if constexpr( is_a_json_type_v<T> ) {
          static_assert( not std::is_same_v<T, void> );
          using type =
            typename daw::conditional_t<is_json_class_map_v<T>,
                                        json_class_map_type<T>,
                                        daw::traits::identity<T>>::type;
          static_assert( not std::is_same_v<daw::remove_cvref_t<type>, void>,
                         "Detection failure" );
          static_assert( not is_nonesuch_v<remove_cvref_t<type>>,
                         "Detection failure" );
          return daw::traits::identity<type>{ };
        } else if constexpr( concepts::is_nullable_value_v<T> ) {
          using value_type = concepts::nullable_value_type_t<T>;
          using sub_type =
            typename decltype( json_deduced_type_impl<value_type>( ) )::type;
          using type = json_base::json_nullable<T, sub_type>;
          return daw::traits::identity<type>{ };
        } else if constexpr( concepts::is_container_v<T> ) {
          using type = json_base::json_array<typename T::value_type, T>;
          return daw::traits::identity<type>{ };
        } else if constexpr( std::is_empty_v<T> and
                             std::is_default_constructible_v<T> ) {
          // Allow empty/default constructible types to work without mapping
          using type = json_details::json_empty_class<T>;
          return daw::traits::identity<type>{ };
        } else if constexpr( can_convert_to_tuple_v<T> ) {
          using type = json_base::json_tuple<T>;
          return daw::traits::identity<type>{ };
        } else {
          static_assert( daw::deduced_false_v<T>,
                         "Could not deduced data contract type" );
        }
      }
 
      template<typename T>
      using json_deduced_type =
        typename DAW_TYPEOF( json_deduced_type_impl<T>( ) )::type;
 
      template<typename T>
      DAW_CPP20_CONCEPT has_json_deduced_type_v =
        not std::is_same_v<json_deduced_type<T>,
                           missing_json_data_contract_for_or_unknown_type<T>>;
 
      template<typename... Ts>
      DAW_CPP20_CONCEPT all_have_deduced_type_v =
        ( has_json_deduced_type_v<Ts> and ... );
 
      template<typename JsonElement, typename Container, typename Constructor>
      struct json_constructor<
        json_base::json_array<JsonElement, Container, Constructor>> {
        using json_element_t = json_deduced_type<JsonElement>;
        using json_element_parse_to_t = json_result_t<json_element_t>;
 
        using container_t =
          daw::conditional_t<std::is_same_v<Container, use_default>,
                             std::vector<json_element_parse_to_t>, Container>;
 
        using type =
          daw::conditional_t<std::is_same_v<use_default, Constructor>,
                             default_constructor<container_t>, Constructor>;
 
        static_assert(
          daw::is_callable_v<type, json_element_parse_to_t const *,
                             json_element_parse_to_t const *>,
          "Constructor must support copy and/or move construction" );
      };
 
      template<typename JsonElement, typename Container, typename Constructor>
      struct json_result<
        json_base::json_array<JsonElement, Container, Constructor>> {
        using constructor_t = typename json_constructor<
          json_base::json_array<JsonElement, Container, Constructor>>::type;
        using json_element_t = json_deduced_type<JsonElement>;
        using json_element_parse_to_t =
          typename json_result<json_element_t>::type;
        using type =
          std::invoke_result_t<constructor_t, json_element_parse_to_t const *,
                               json_element_parse_to_t const *>;
      };
 
      template<typename T>
      DAW_CPP20_CONCEPT has_unnamed_default_type_mapping_v =
        has_json_deduced_type_v<T>;
 
      template<typename JsonMember>
      using from_json_result_t = json_result_t<json_deduced_type<JsonMember>>;
 
      template<typename Constructor, typename... Members>
      using json_class_parse_result_impl2 =
        std::invoke_result_t<Constructor, json_result_t<Members>...>;
 
      template<typename Constructor, typename... Members>
      using json_class_parse_result_impl =
        daw::detected_t<json_class_parse_result_impl2, Constructor, Members...>;
 
      template<typename Constructor, typename... Members>
      struct could_not_construct_from_members_error;
 
      template<typename Constructor, typename... Members>
      using json_class_parse_result_t = typename daw::conditional_t<
        daw::is_callable_v<Constructor, json_result_t<Members>...>,
        std::invoke_result<Constructor, json_result_t<Members>...>,
        daw::traits::identity<could_not_construct_from_members_error<
          Constructor, Members...>>>::type;
 
      template<typename JsonMember>
      using dependent_member_t = typename JsonMember::dependent_member;
 
      template<typename JsonMember, typename = void>
      inline constexpr bool has_dependent_member_v = false;
 
      template<typename JsonMember>
      inline constexpr bool has_dependent_member_v<
        JsonMember, std::void_t<dependent_member_t<JsonMember>>> = true;
 
      DAW_JSON_MAKE_REQ_TYPE_ALIAS_TRAIT( has_nullable_dependent_member_v,
                                          T::member_type::dependent_member );
 
      template<typename JsonMember>
      DAW_REQUIRES( is_json_nullable_v<JsonMember> )
      inline constexpr bool has_dependent_member_v<
        JsonMember DAW_ENABLEIF_S( is_json_nullable_v<JsonMember> )> =
        has_nullable_dependent_member_v<JsonMember>;
 
      template<typename Constructor>
      [[nodiscard]] DAW_ATTRIB_INLINE constexpr auto
      construct_nullable_empty( ) {
        if constexpr( daw::is_callable_v<
                        Constructor,
                        concepts::construct_nullable_with_empty_t> ) {
          return Constructor{ }( concepts::construct_nullable_with_empty );
        } else {
          return Constructor{ }( );
        }
      }
    } // namespace json_details
  } // namespace DAW_JSON_VER
} // namespace daw::json