diff --git a/libcxx/include/__functional/boyer_moore_searcher.h b/libcxx/include/__functional/boyer_moore_searcher.h
index 7889232f4b919..019d470487081 100644
--- a/libcxx/include/__functional/boyer_moore_searcher.h
+++ b/libcxx/include/__functional/boyer_moore_searcher.h
@@ -125,8 +125,8 @@ class boyer_moore_searcher {
   template <class _RandomAccessIterator2>
   _LIBCPP_HIDE_FROM_ABI pair<_RandomAccessIterator2, _RandomAccessIterator2>
   operator()(_RandomAccessIterator2 __first, _RandomAccessIterator2 __last) const {
-    static_assert(__is_same_uncvref<typename iterator_traits<_RandomAccessIterator1>::value_type,
-                                    typename iterator_traits<_RandomAccessIterator2>::value_type>::value,
+    static_assert(is_same_v<typename iterator_traits<_RandomAccessIterator1>::value_type,
+                            typename iterator_traits<_RandomAccessIterator2>::value_type>,
                   "Corpus and Pattern iterators must point to the same type");
     if (__first == __last)
       return std::make_pair(__last, __last);
@@ -256,8 +256,8 @@ class boyer_moore_horspool_searcher {
   template <class _RandomAccessIterator2>
   _LIBCPP_HIDE_FROM_ABI pair<_RandomAccessIterator2, _RandomAccessIterator2>
   operator()(_RandomAccessIterator2 __first, _RandomAccessIterator2 __last) const {
-    static_assert(__is_same_uncvref<typename std::iterator_traits<_RandomAccessIterator1>::value_type,
-                                    typename std::iterator_traits<_RandomAccessIterator2>::value_type>::value,
+    static_assert(is_same_v<typename std::iterator_traits<_RandomAccessIterator1>::value_type,
+                            typename std::iterator_traits<_RandomAccessIterator2>::value_type>,
                   "Corpus and Pattern iterators must point to the same type");
     if (__first == __last)
       return std::make_pair(__last, __last);
diff --git a/libcxx/include/__functional/reference_wrapper.h b/libcxx/include/__functional/reference_wrapper.h
index b409ad7511f6c..1914ef5b31a57 100644
--- a/libcxx/include/__functional/reference_wrapper.h
+++ b/libcxx/include/__functional/reference_wrapper.h
@@ -45,7 +45,7 @@ class reference_wrapper : public __weak_result_type<_Tp> {
 public:
   template <class _Up,
             class = __void_t<decltype(__fun(std::declval<_Up>()))>,
-            __enable_if_t<!__is_same_uncvref<_Up, reference_wrapper>::value, int> = 0>
+            __enable_if_t<!is_same<__remove_cvref_t<_Up>, reference_wrapper>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 reference_wrapper(_Up&& __u)
       _NOEXCEPT_(noexcept(__fun(std::declval<_Up>()))) {
     type& __f = static_cast<_Up&&>(__u);
diff --git a/libcxx/include/__hash_table b/libcxx/include/__hash_table
index 61bc029dce4e6..7fe035c60224a 100644
--- a/libcxx/include/__hash_table
+++ b/libcxx/include/__hash_table
@@ -193,12 +193,12 @@ struct __hash_key_value_types<__hash_value_type<_Key, _Tp> > {
 
   _LIBCPP_HIDE_FROM_ABI static key_type const& __get_key(__container_value_type const& __v) { return __v.first; }
 
-  template <class _Up, __enable_if_t<__is_same_uncvref<_Up, __node_value_type>::value, int> = 0>
+  template <class _Up, __enable_if_t<is_same<__remove_cvref_t<_Up>, __node_value_type>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI static __container_value_type const& __get_value(_Up& __t) {
     return __t.__get_value();
   }
 
-  template <class _Up, __enable_if_t<__is_same_uncvref<_Up, __container_value_type>::value, int> = 0>
+  template <class _Up, __enable_if_t<is_same<__remove_cvref_t<_Up>, __container_value_type>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI static __container_value_type const& __get_value(_Up& __t) {
     return __t;
   }
@@ -842,7 +842,7 @@ public:
     return __emplace_unique_key_args(_NodeTypes::__get_key(__x), std::move(__x));
   }
 
-  template <class _Pp, __enable_if_t<!__is_same_uncvref<_Pp, __container_value_type>::value, int> = 0>
+  template <class _Pp, __enable_if_t<!is_same<__remove_cvref_t<_Pp>, __container_value_type>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI pair<iterator, bool> __insert_unique(_Pp&& __x) {
     return __emplace_unique(std::forward<_Pp>(__x));
   }
diff --git a/libcxx/include/__tree b/libcxx/include/__tree
index 403cfe1ba4036..7eca34f2402bf 100644
--- a/libcxx/include/__tree
+++ b/libcxx/include/__tree
@@ -521,7 +521,7 @@ struct __tree_key_value_types<__value_type<_Key, _Tp> > {
   typedef __container_value_type __map_value_type;
   static const bool __is_map = true;
 
-  template <class _Up, __enable_if_t<__is_same_uncvref<_Up, __container_value_type>::value, int> = 0>
+  template <class _Up, __enable_if_t<is_same<__remove_cvref_t<_Up>, __container_value_type>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI static key_type const& __get_key(_Up& __t) {
     return __t.first;
   }
diff --git a/libcxx/include/__type_traits/remove_cvref.h b/libcxx/include/__type_traits/remove_cvref.h
index 760deddca946d..c568e8df3099d 100644
--- a/libcxx/include/__type_traits/remove_cvref.h
+++ b/libcxx/include/__type_traits/remove_cvref.h
@@ -10,7 +10,6 @@
 #define _LIBCPP___TYPE_TRAITS_REMOVE_CVREF_H
 
 #include <__config>
-#include <__type_traits/is_same.h>
 
 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
 #  pragma GCC system_header
@@ -31,9 +30,6 @@ template <class _Tp>
 using __remove_cvref_t _LIBCPP_NODEBUG = __remove_cvref(_Tp);
 #endif // __has_builtin(__remove_cvref)
 
-template <class _Tp, class _Up>
-using __is_same_uncvref _LIBCPP_NODEBUG = _IsSame<__remove_cvref_t<_Tp>, __remove_cvref_t<_Up> >;
-
 #if _LIBCPP_STD_VER >= 20
 template <class _Tp>
 struct _LIBCPP_NO_SPECIALIZATIONS remove_cvref {
diff --git a/libcxx/include/string b/libcxx/include/string
index 48d43b78d4bd1..eedb3a1ea502d 100644
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -1127,7 +1127,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
   basic_string(const _Tp& __t, size_type __pos, size_type __n, const allocator_type& __a = allocator_type())
@@ -1139,7 +1139,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const _Tp& __t) {
     __self_view __sv = __t;
@@ -1148,7 +1148,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 explicit basic_string(const _Tp& __t, const allocator_type& __a)
       : __alloc_(__a) {
@@ -1207,7 +1207,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator=(const _Tp& __t) {
     __self_view __sv = __t;
@@ -1344,7 +1344,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string >::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string >::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& operator+=(const _Tp& __t) {
     __self_view __sv = __t;
@@ -1373,7 +1373,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string& append(const _Tp& __t) {
     __self_view __sv = __t;
@@ -1384,7 +1384,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
   append(const _Tp& __t, size_type __pos, size_type __n = npos) {
@@ -1511,7 +1511,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
   assign(const _Tp& __t, size_type __pos, size_type __n = npos) {
@@ -1581,7 +1581,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
   insert(size_type __pos1, const _Tp& __t, size_type __pos2, size_type __n = npos) {
@@ -1662,7 +1662,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string&
   replace(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2 = npos) {
@@ -2007,7 +2007,7 @@ public:
 
   template <class _Tp,
             __enable_if_t<__can_be_converted_to_string_view<_CharT, _Traits, _Tp>::value &&
-                              !__is_same_uncvref<_Tp, basic_string>::value,
+                              !is_same<__remove_cvref_t<_Tp>, basic_string>::value,
                           int> = 0>
   inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 int
   compare(size_type __pos1, size_type __n1, const _Tp& __t, size_type __pos2, size_type __n2 = npos) const {
diff --git a/libcxx/include/unordered_map b/libcxx/include/unordered_map
index 61c89a0ca73bb..187795e8b43a7 100644
--- a/libcxx/include/unordered_map
+++ b/libcxx/include/unordered_map
@@ -890,7 +890,7 @@ public:
     return *this;
   }
 
-  template <class _ValueTp, __enable_if_t<__is_same_uncvref<_ValueTp, value_type>::value, int> = 0>
+  template <class _ValueTp, __enable_if_t<is_same<__remove_cvref_t<_ValueTp>, value_type>::value, int> = 0>
   _LIBCPP_HIDE_FROM_ABI __hash_value_type& operator=(_ValueTp&& __v) {
     __ref() = std::forward<_ValueTp>(__v);
     return *this;