diff --git a/headers/meta.hpp/meta_base.hpp b/headers/meta.hpp/meta_base.hpp
index 1eefff8..0840599 100644
--- a/headers/meta.hpp/meta_base.hpp
+++ b/headers/meta.hpp/meta_base.hpp
@@ -39,10 +39,11 @@
 #include "meta_base/cvref_traits.hpp"
 #include "meta_base/fixed_function.hpp"
 #include "meta_base/hash_combiner.hpp"
+#include "meta_base/is_in_place_type.hpp"
 #include "meta_base/noncopyable.hpp"
 #include "meta_base/overloaded.hpp"
 #include "meta_base/select_overload.hpp"
-#include "meta_base/stdex.hpp"
+#include "meta_base/to_underlying.hpp"
 #include "meta_base/type_id.hpp"
 #include "meta_base/type_kinds.hpp"
 #include "meta_base/type_list.hpp"
diff --git a/headers/meta.hpp/meta_base/stdex.hpp b/headers/meta.hpp/meta_base/is_in_place_type.hpp
similarity index 74%
rename from headers/meta.hpp/meta_base/stdex.hpp
rename to headers/meta.hpp/meta_base/is_in_place_type.hpp
index d13bf68..b9c0648 100644
--- a/headers/meta.hpp/meta_base/stdex.hpp
+++ b/headers/meta.hpp/meta_base/is_in_place_type.hpp
@@ -9,7 +9,7 @@
 #include <type_traits>
 #include <utility>
 
-namespace meta_hpp::stdex
+namespace meta_hpp::detail
 {
     template < typename T >
     struct is_in_place_type : std::false_type {};
@@ -20,11 +20,3 @@ namespace meta_hpp::stdex
     template < typename T >
     inline constexpr bool is_in_place_type_v = is_in_place_type<T>::value;
 }
-
-namespace meta_hpp::stdex
-{
-    template < typename Enum >
-    [[nodiscard]] constexpr std::underlying_type_t<Enum> to_underlying(Enum e) noexcept {
-        return static_cast<std::underlying_type_t<Enum>>(e);
-    }
-}
diff --git a/headers/meta.hpp/meta_base/to_underlying.hpp b/headers/meta.hpp/meta_base/to_underlying.hpp
new file mode 100644
index 0000000..f4bd77f
--- /dev/null
+++ b/headers/meta.hpp/meta_base/to_underlying.hpp
@@ -0,0 +1,17 @@
+/*******************************************************************************
+ * This file is part of the "https://github.com/blackmatov/meta.hpp"
+ * For conditions of distribution and use, see copyright notice in LICENSE.md
+ * Copyright (C) 2021-2022, by Matvey Cherevko (blackmatov@gmail.com)
+ ******************************************************************************/
+
+#pragma once
+
+#include <type_traits>
+
+namespace meta_hpp::detail
+{
+    template < typename Enum >
+    [[nodiscard]] constexpr std::underlying_type_t<Enum> to_underlying(Enum e) noexcept {
+        return static_cast<std::underlying_type_t<Enum>>(e);
+    }
+}
diff --git a/headers/meta.hpp/meta_states/constructor.hpp b/headers/meta.hpp/meta_states/constructor.hpp
index 5283ce5..6fd5840 100644
--- a/headers/meta.hpp/meta_states/constructor.hpp
+++ b/headers/meta.hpp/meta_states/constructor.hpp
@@ -87,7 +87,7 @@ namespace meta_hpp::detail
 
     template < class_kind Class, typename... Args >
     argument_list make_constructor_arguments() {
-        using ct = detail::constructor_traits<Class, Args...>;
+        using ct = constructor_traits<Class, Args...>;
         using ct_argument_types = typename ct::argument_types;
 
         argument_list arguments;
@@ -95,8 +95,8 @@ namespace meta_hpp::detail
 
         [&arguments]<std::size_t... Is>(std::index_sequence<Is...>) mutable {
             [[maybe_unused]] const auto make_argument = []<std::size_t I>(std::index_sequence<I>){
-                using P = detail::type_list_at_t<I, ct_argument_types>;
-                return argument{detail::argument_state::make<P>(I, metadata_map{})};
+                using P = type_list_at_t<I, ct_argument_types>;
+                return argument{argument_state::make<P>(I, metadata_map{})};
             };
             (arguments.push_back(make_argument(std::index_sequence<Is>{})), ...);
         }(std::make_index_sequence<ct::arity>());
diff --git a/headers/meta.hpp/meta_states/evalue.hpp b/headers/meta.hpp/meta_states/evalue.hpp
index 1f74966..ad40296 100644
--- a/headers/meta.hpp/meta_states/evalue.hpp
+++ b/headers/meta.hpp/meta_states/evalue.hpp
@@ -19,7 +19,7 @@ namespace meta_hpp::detail
             .index{evalue_index::make<Enum>(std::move(name))},
             .metadata{std::move(metadata)},
             .enum_value{uvalue{evalue}},
-            .underlying_value{uvalue{stdex::to_underlying(evalue)}},
+            .underlying_value{uvalue{to_underlying(evalue)}},
         });
     }
 }
diff --git a/headers/meta.hpp/meta_states/function.hpp b/headers/meta.hpp/meta_states/function.hpp
index dbd5120..eea4091 100644
--- a/headers/meta.hpp/meta_states/function.hpp
+++ b/headers/meta.hpp/meta_states/function.hpp
@@ -95,7 +95,7 @@ namespace meta_hpp::detail
 
     template < function_kind Function >
     argument_list make_function_arguments() {
-        using ft = detail::function_traits<Function>;
+        using ft = function_traits<Function>;
         using ft_argument_types = typename ft::argument_types;
 
         argument_list arguments;
@@ -103,8 +103,8 @@ namespace meta_hpp::detail
 
         [&arguments]<std::size_t... Is>(std::index_sequence<Is...>) mutable {
             [[maybe_unused]] const auto make_argument = []<std::size_t I>(std::index_sequence<I>){
-                using P = detail::type_list_at_t<I, ft_argument_types>;
-                return argument{detail::argument_state::make<P>(I, metadata_map{})};
+                using P = type_list_at_t<I, ft_argument_types>;
+                return argument{argument_state::make<P>(I, metadata_map{})};
             };
             (arguments.push_back(make_argument(std::index_sequence<Is>{})), ...);
         }(std::make_index_sequence<ft::arity>());
diff --git a/headers/meta.hpp/meta_states/method.hpp b/headers/meta.hpp/meta_states/method.hpp
index 09c222c..5a3c212 100644
--- a/headers/meta.hpp/meta_states/method.hpp
+++ b/headers/meta.hpp/meta_states/method.hpp
@@ -106,7 +106,7 @@ namespace meta_hpp::detail
 
     template < method_kind Method >
     argument_list make_method_arguments() {
-        using mt = detail::method_traits<Method>;
+        using mt = method_traits<Method>;
         using mt_argument_types = typename mt::argument_types;
 
         argument_list arguments;
@@ -114,8 +114,8 @@ namespace meta_hpp::detail
 
         [&arguments]<std::size_t... Is>(std::index_sequence<Is...>) mutable {
             [[maybe_unused]] const auto make_argument = []<std::size_t I>(std::index_sequence<I>){
-                using P = detail::type_list_at_t<I, mt_argument_types>;
-                return argument{detail::argument_state::make<P>(I, metadata_map{})};
+                using P = type_list_at_t<I, mt_argument_types>;
+                return argument{argument_state::make<P>(I, metadata_map{})};
             };
             (arguments.push_back(make_argument(std::index_sequence<Is>{})), ...);
         }(std::make_index_sequence<mt::arity>());
diff --git a/headers/meta.hpp/meta_uvalue.hpp b/headers/meta.hpp/meta_uvalue.hpp
index 368b3b9..c179a1d 100644
--- a/headers/meta.hpp/meta_uvalue.hpp
+++ b/headers/meta.hpp/meta_uvalue.hpp
@@ -39,7 +39,7 @@ namespace meta_hpp
 
         template < detail::decay_non_value_kind T >
             requires std::is_copy_constructible_v<std::decay_t<T>>
-                && (!stdex::is_in_place_type_v<std::remove_cvref_t<T>>)
+                && (!detail::is_in_place_type_v<std::remove_cvref_t<T>>)
         // NOLINTNEXTLINE(*-forwarding-reference-overload)
         explicit uvalue(T&& val);
 
diff --git a/headers/meta.hpp/meta_uvalue/uvalue.hpp b/headers/meta.hpp/meta_uvalue/uvalue.hpp
index 6f9db24..3a2fabd 100644
--- a/headers/meta.hpp/meta_uvalue/uvalue.hpp
+++ b/headers/meta.hpp/meta_uvalue/uvalue.hpp
@@ -257,7 +257,7 @@ namespace meta_hpp
 
     template < detail::decay_non_value_kind T >
         requires std::is_copy_constructible_v<std::decay_t<T>>
-            && (!stdex::is_in_place_type_v<std::remove_cvref_t<T>>)
+            && (!detail::is_in_place_type_v<std::remove_cvref_t<T>>)
     // NOLINTNEXTLINE(*-forwarding-reference-overload)
     uvalue::uvalue(T&& val) {
         vtable_t::construct<T>(*this, std::forward<T>(val));
diff --git a/singles/headers/meta.hpp/meta_all.hpp b/singles/headers/meta.hpp/meta_all.hpp
index 5b96df1..541a989 100644
--- a/singles/headers/meta.hpp/meta_all.hpp
+++ b/singles/headers/meta.hpp/meta_all.hpp
@@ -495,6 +495,18 @@ namespace meta_hpp::detail
     };
 }
 
+namespace meta_hpp::detail
+{
+    template < typename T >
+    struct is_in_place_type : std::false_type {};
+
+    template < typename U >
+    struct is_in_place_type<std::in_place_type_t<U>> : std::true_type {};
+
+    template < typename T >
+    inline constexpr bool is_in_place_type_v = is_in_place_type<T>::value;
+}
+
 namespace meta_hpp::detail
 {
     class noncopyable {
@@ -553,19 +565,7 @@ namespace meta_hpp::detail
     }
 }
 
-namespace meta_hpp::stdex
-{
-    template < typename T >
-    struct is_in_place_type : std::false_type {};
-
-    template < typename U >
-    struct is_in_place_type<std::in_place_type_t<U>> : std::true_type {};
-
-    template < typename T >
-    inline constexpr bool is_in_place_type_v = is_in_place_type<T>::value;
-}
-
-namespace meta_hpp::stdex
+namespace meta_hpp::detail
 {
     template < typename Enum >
     [[nodiscard]] constexpr std::underlying_type_t<Enum> to_underlying(Enum e) noexcept {
@@ -2228,7 +2228,7 @@ namespace meta_hpp
 
         template < detail::decay_non_value_kind T >
             requires std::is_copy_constructible_v<std::decay_t<T>>
-                && (!stdex::is_in_place_type_v<std::remove_cvref_t<T>>)
+                && (!detail::is_in_place_type_v<std::remove_cvref_t<T>>)
         // NOLINTNEXTLINE(*-forwarding-reference-overload)
         explicit uvalue(T&& val);
 
@@ -5227,7 +5227,7 @@ namespace meta_hpp::detail
 
     template < class_kind Class, typename... Args >
     argument_list make_constructor_arguments() {
-        using ct = detail::constructor_traits<Class, Args...>;
+        using ct = constructor_traits<Class, Args...>;
         using ct_argument_types = typename ct::argument_types;
 
         argument_list arguments;
@@ -5235,8 +5235,8 @@ namespace meta_hpp::detail
 
         [&arguments]<std::size_t... Is>(std::index_sequence<Is...>) mutable {
             [[maybe_unused]] const auto make_argument = []<std::size_t I>(std::index_sequence<I>){
-                using P = detail::type_list_at_t<I, ct_argument_types>;
-                return argument{detail::argument_state::make<P>(I, metadata_map{})};
+                using P = type_list_at_t<I, ct_argument_types>;
+                return argument{argument_state::make<P>(I, metadata_map{})};
             };
             (arguments.push_back(make_argument(std::index_sequence<Is>{})), ...);
         }(std::make_index_sequence<ct::arity>());
@@ -5573,7 +5573,7 @@ namespace meta_hpp::detail
             .index{evalue_index::make<Enum>(std::move(name))},
             .metadata{std::move(metadata)},
             .enum_value{uvalue{evalue}},
-            .underlying_value{uvalue{stdex::to_underlying(evalue)}},
+            .underlying_value{uvalue{to_underlying(evalue)}},
         });
     }
 }
@@ -5759,7 +5759,7 @@ namespace meta_hpp::detail
 
     template < function_kind Function >
     argument_list make_function_arguments() {
-        using ft = detail::function_traits<Function>;
+        using ft = function_traits<Function>;
         using ft_argument_types = typename ft::argument_types;
 
         argument_list arguments;
@@ -5767,8 +5767,8 @@ namespace meta_hpp::detail
 
         [&arguments]<std::size_t... Is>(std::index_sequence<Is...>) mutable {
             [[maybe_unused]] const auto make_argument = []<std::size_t I>(std::index_sequence<I>){
-                using P = detail::type_list_at_t<I, ft_argument_types>;
-                return argument{detail::argument_state::make<P>(I, metadata_map{})};
+                using P = type_list_at_t<I, ft_argument_types>;
+                return argument{argument_state::make<P>(I, metadata_map{})};
             };
             (arguments.push_back(make_argument(std::index_sequence<Is>{})), ...);
         }(std::make_index_sequence<ft::arity>());
@@ -6542,7 +6542,7 @@ namespace meta_hpp::detail
 
     template < method_kind Method >
     argument_list make_method_arguments() {
-        using mt = detail::method_traits<Method>;
+        using mt = method_traits<Method>;
         using mt_argument_types = typename mt::argument_types;
 
         argument_list arguments;
@@ -6550,8 +6550,8 @@ namespace meta_hpp::detail
 
         [&arguments]<std::size_t... Is>(std::index_sequence<Is...>) mutable {
             [[maybe_unused]] const auto make_argument = []<std::size_t I>(std::index_sequence<I>){
-                using P = detail::type_list_at_t<I, mt_argument_types>;
-                return argument{detail::argument_state::make<P>(I, metadata_map{})};
+                using P = type_list_at_t<I, mt_argument_types>;
+                return argument{argument_state::make<P>(I, metadata_map{})};
             };
             (arguments.push_back(make_argument(std::index_sequence<Is>{})), ...);
         }(std::make_index_sequence<mt::arity>());
@@ -8260,7 +8260,7 @@ namespace meta_hpp
 
     template < detail::decay_non_value_kind T >
         requires std::is_copy_constructible_v<std::decay_t<T>>
-            && (!stdex::is_in_place_type_v<std::remove_cvref_t<T>>)
+            && (!detail::is_in_place_type_v<std::remove_cvref_t<T>>)
     // NOLINTNEXTLINE(*-forwarding-reference-overload)
     uvalue::uvalue(T&& val) {
         vtable_t::construct<T>(*this, std::forward<T>(val));
diff --git a/untests/meta_states/evalue_tests.cpp b/untests/meta_states/evalue_tests.cpp
index ddfd4db..961ad44 100644
--- a/untests/meta_states/evalue_tests.cpp
+++ b/untests/meta_states/evalue_tests.cpp
@@ -56,7 +56,7 @@ TEST_CASE("meta/meta_states/evalue") {
         CHECK(evalue.get_value() == color::green);
         CHECK(evalue.get_value().get_type() == color_type);
 
-        CHECK(evalue.get_underlying_value() == meta::stdex::to_underlying(color::green));
+        CHECK(evalue.get_underlying_value() == meta::detail::to_underlying(color::green));
         CHECK(evalue.get_underlying_value().get_type() == color_type.get_underlying_type());
     }
 }
diff --git a/untests/meta_types/enum_type_tests.cpp b/untests/meta_types/enum_type_tests.cpp
index e312a6f..764ebc0 100644
--- a/untests/meta_types/enum_type_tests.cpp
+++ b/untests/meta_types/enum_type_tests.cpp
@@ -90,7 +90,7 @@ TEST_CASE("meta/meta_types/enum_type") {
             const meta::evalue green_value = color_type.get_evalue("green");
             REQUIRE(green_value);
             CHECK(green_value.get_value() == color::green);
-            CHECK(green_value.get_underlying_value() == meta::stdex::to_underlying(color::green));
+            CHECK(green_value.get_underlying_value() == meta::detail::to_underlying(color::green));
         }
 
         {
@@ -107,7 +107,7 @@ TEST_CASE("meta/meta_types/enum_type") {
             const meta::evalue green_value = ecolor_type.get_evalue("green");
             REQUIRE(green_value);
             CHECK(green_value.get_value() == ecolor_green);
-            CHECK(green_value.get_underlying_value() == meta::stdex::to_underlying(ecolor_green));
+            CHECK(green_value.get_underlying_value() == meta::detail::to_underlying(ecolor_green));
         }
 
         {