🔥 Remove a couple of now-standard type traits

docs/type_traits.adoc

@@ -7,9 +7,7 @@ contains a few things from the standard:
 * https://en.cppreference.com/w/cpp/types/conditional[`conditional_t`]
   (implemented with fewer template instantiations than a typical standard
   implementation)
-* https://en.cppreference.com/w/cpp/types/is_constant_evaluated[`is_constant_evaluated`] (from C++20)
 * https://en.cppreference.com/w/cpp/types/is_function[`is_function_v`] (implemented with Walter Brown's method)
-* https://en.cppreference.com/w/cpp/types/is_scoped_enum[`is_scoped_enum_v`] (from C++23)
 * https://en.cppreference.com/w/cpp/utility/to_underlying[`to_underlying`] (from C++23)
 * https://en.cppreference.com/w/cpp/types/type_identity[`type_identity`] (from C++20)
 

include/stdx/tuple.hpp

@@ -1,6 +1,7 @@
 #pragma once
 
 #include <stdx/concepts.hpp>
+#include <stdx/ct_conversions.hpp>
 #include <stdx/type_traits.hpp>
 #include <stdx/udls.hpp>
 #include <stdx/utility.hpp>
@@ -27,7 +28,6 @@ template <typename> struct tag_constant;
 template <typename T> constexpr static tag_constant<T> *tag{};
 
 namespace error {
-template <typename...> constexpr auto always_false_v = false;
 template <typename T> struct type_from_tag_constant {
     using type = T;
 };

include/stdx/type_traits.hpp

@@ -66,10 +66,6 @@ constexpr bool is_function_object_v = detail::is_func_obj<T>;
 template <typename T>
 constexpr bool is_callable_v = is_function_v<T> or is_function_object_v<T>;
 
-constexpr auto is_constant_evaluated() noexcept -> bool {
-    return __builtin_is_constant_evaluated();
-}
-
 template <typename T> struct type_identity {
     using type = T;
 };
@@ -115,12 +111,6 @@ constexpr auto is_specialization_of()
     return {};
 }
 
-template <typename E>
-constexpr bool is_scoped_enum_v =
-    std::is_enum_v<E> and not std::is_convertible_v<E, underlying_type_t<E>>;
-template <typename E>
-using is_scoped_enum = std::bool_constant<is_scoped_enum_v<E>>;
-
 template <typename...> struct type_list {};
 template <auto...> struct value_list {};
 

test/CMakeLists.txt

@@ -53,7 +53,6 @@ add_tests(
     intrusive_forward_list
     intrusive_list
     intrusive_list_properties
-    is_constant_evaluated
     iterator
     latched
     numeric

test/type_traits.cpp

@@ -71,21 +71,6 @@ TEST_CASE("derived types are not specializations (value templates)",
         not stdx::is_specialization_of<value_derived_t<0>, value_unary_t>());
 }
 
-namespace {
-enum E1 {};
-enum struct E2 {};
-} // namespace
-
-TEST_CASE("is_scoped_enum", "[type_traits]") {
-    STATIC_REQUIRE(not stdx::is_scoped_enum_v<int>);
-    STATIC_REQUIRE(not stdx::is_scoped_enum_v<E1>);
-    STATIC_REQUIRE(stdx::is_scoped_enum_v<E2>);
-
-    STATIC_REQUIRE(not stdx::is_scoped_enum<int>::value);
-    STATIC_REQUIRE(not stdx::is_scoped_enum<E1>::value);
-    STATIC_REQUIRE(stdx::is_scoped_enum<E2>::value);
-}
-
 TEST_CASE("type_identity", "[type_traits]") {
     STATIC_REQUIRE(std::is_same_v<stdx::type_identity_t<void>, void>);
 }