fix: build error for more is and as

cd4a67d

include/json.hpp

@@ -43,6 +43,22 @@ namespace utils
     using iter_value_t = typename std::iterator_traits<remove_cvref_t<T>>::value_type;
     template <typename R>
     using range_value_t = iter_value_t<iterator_t<R>>;
+
+    template <typename T, typename = void>
+    constexpr bool is_container = false;
+    template <typename T>
+    constexpr bool is_container<T, std::void_t<typename T::value_type, utils::range_value_t<T>>> =
+        std::is_same_v<typename T::value_type, utils::range_value_t<T>>;
+
+    template <typename T, typename = void>
+    constexpr bool is_map = false;
+    template <typename T>
+    constexpr bool is_map<T, std::void_t<typename T::key_type, typename T::mapped_type>> = is_container<T>;
+
+    template <typename T, typename = void>
+    constexpr bool is_collection = false;
+    template <typename T>
+    constexpr bool is_collection<T> = is_container<T> && !is_map<T>;
 }
 
 // *********************************
@@ -205,13 +221,13 @@ class basic_value
     // deprecated, please use as_collection instead.
     vector_t<value_t> to_vector() const
     {
-        return template to_vector<value_t, vector_t>();
+        return to_vector<value_t, vector_t>();
     }
     template <typename value_t, template <typename...> typename map_t = std::map>
     // deprecated, please use as_map instead.
     map_t<string_t, value_t> to_map() const
     {
-        return template as_map<value_t, map_t>();
+        return as_map<value_t, map_t>();
     }
 
     basic_value<string_t>& operator=(const basic_value<string_t>& rhs);
@@ -254,13 +270,13 @@ class basic_value
     explicit operator string_t() const { return as_string(); }
 
     template <typename value_t, template <typename...> typename collection_t = std::vector,
-              typename _ = std::enable_if_t<_serialization_helper::is_collection<collection_t<value_t>>>>
+              typename _ = std::enable_if_t<utils::is_collection<collection_t<value_t>>>>
     explicit operator collection_t<value_t>() const
     {
         return as_collection<value_t, collection_t>();
     }
     template <typename value_t, template <typename...> typename map_t = std::map,
-              typename _ = std::enable_if_t<_serialization_helper::is_map<map_t<string_t, value_t>>>>
+              typename _ = std::enable_if_t<utils::is_map<map_t<string_t, value_t>>>>
     explicit operator map_t<string_t, value_t>() const
     {
         return as_map<value_t, map_t>();
@@ -767,13 +783,13 @@ inline bool basic_value<string_t>::is() const noexcept
     else if constexpr (std::is_same_v<basic_array<string_t>, value_t>) {
         return is_array();
     }
-    else if constexpr (_serialization_helper::is_collection<value_t>) {
+    else if constexpr (utils::is_collection<value_t>) {
         return is_array() && all<typename value_t::value_type>();
     }
     else if constexpr (std::is_same_v<basic_object<string_t>, value_t>) {
         return is_object();
     }
-    else if constexpr (_serialization_helper::is_map<value_t>) {
+    else if constexpr (utils::is_map<value_t>) {
         return is_object() && std::is_constructible_v<string_t, typename value_t::key_type> &&
                all<typename value_t::mapped_type>();
     }
@@ -2619,22 +2635,6 @@ namespace _serialization_helper
         static constexpr bool value = decltype(test<T>(0))::value;
     };
 
-    template <typename T, typename = void>
-    constexpr bool is_container = false;
-    template <typename T>
-    constexpr bool is_container<T, std::void_t<typename T::value_type, utils::range_value_t<T>>> =
-        std::is_same_v<typename T::value_type, utils::range_value_t<T>>;
-
-    template <typename T, typename = void>
-    constexpr bool is_map = false;
-    template <typename T>
-    constexpr bool is_map<T, std::void_t<typename T::key_type, typename T::mapped_type>> = is_container<T>;
-
-    template <typename T, typename = void>
-    constexpr bool is_collection = false;
-    template <typename T>
-    constexpr bool is_collection<T> = is_container<T> && !is_map<T>;
-
     template <bool loose, typename string_t>
     struct string_converter
     {
@@ -2697,7 +2697,7 @@ basic_value<string_t> serialize(any_t&& arg, string_converter_t&& string_convert
     else if constexpr (std::decay_t<string_converter_t>::template is_convertible<any_t>) {
         return string_converter(std::forward<any_t>(arg));
     }
-    else if constexpr (is_collection<std::decay_t<any_t>>) {
+    else if constexpr (utils::is_collection<std::decay_t<any_t>>) {
         basic_value<string_t> result;
         for (auto&& val : arg) {
             using value_t = decltype(val);
@@ -2707,7 +2707,7 @@ basic_value<string_t> serialize(any_t&& arg, string_converter_t&& string_convert
         }
         return result;
     }
-    else if constexpr (is_map<std::decay_t<any_t>>) {
+    else if constexpr (utils::is_map<std::decay_t<any_t>>) {
         basic_value<string_t> result;
         for (auto&& [key, val] : arg) {
             using key_t = decltype(key);