diff --git a/stl/inc/chrono b/stl/inc/chrono
index de19558606..8607c41f40 100644
--- a/stl/inc/chrono
+++ b/stl/inc/chrono
@@ -35,12 +35,9 @@
 
 #ifdef __cpp_lib_concepts
 #include <concepts>
-#endif // defined(__cpp_lib_concepts)
-
-#ifdef __cpp_lib_format
 #include <format>
 #include <iomanip>
-#endif // defined(__cpp_lib_format)
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX20
 
 #pragma pack(push, _CRT_PACKING)
@@ -1683,7 +1680,7 @@ namespace chrono {
             : runtime_error(_Make_string(_Tp, _Info)) {}
 
     private:
-#ifdef __cpp_lib_format
+#ifdef __cpp_lib_concepts
         template <class _Duration>
         _NODISCARD static string _Make_string(const local_time<_Duration>& _Tp, const local_info& _Info);
 #else // ^^^ no workaround / workaround vvv
@@ -1706,7 +1703,7 @@ namespace chrono {
             : runtime_error(_Make_string(_Tp, _Info)) {}
 
     private:
-#ifdef __cpp_lib_format
+#ifdef __cpp_lib_concepts
         template <class _Duration>
         _NODISCARD static string _Make_string(const local_time<_Duration>& _Tp, const local_info& _Info);
 #else // ^^^ no workaround / workaround vvv
@@ -4653,7 +4650,7 @@ namespace chrono {
     }
 } // namespace chrono
 
-#ifdef __cpp_lib_format
+#ifdef __cpp_lib_concepts
   // [time.format]
 
 template <class _CharT>
@@ -5984,7 +5981,7 @@ namespace chrono {
         return _STD move(_Os).str();
     }
 } // namespace chrono
-#endif // __cpp_lib_format
+#endif // __cpp_lib_concepts
 
 inline namespace literals {
     inline namespace chrono_literals {
diff --git a/stl/inc/deque b/stl/inc/deque
index ed51e39aba..71cdb8ac5a 100644
--- a/stl/inc/deque
+++ b/stl/inc/deque
@@ -673,7 +673,7 @@ public:
         _Proxy._Release();
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     deque(from_range_t, _Rng&& _Range) : _Mypair(_Zero_then_variadic_args_t{}) {
         _Alproxy_ty _Alproxy(_Getal());
@@ -689,7 +689,7 @@ public:
         _Construct(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         _Proxy._Release();
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 private:
     template <class _Iter, class _Sent>
@@ -790,7 +790,7 @@ public:
         emplace_front(_STD move(_Val));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void prepend_range(_Rng&& _Range) {
         _Orphan_all();
@@ -815,14 +815,14 @@ public:
         }
         _Guard._Container = nullptr;
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void push_back(_Ty&& _Val) {
         _Orphan_all();
         _Emplace_back_internal(_STD move(_Val));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void append_range(_Rng&& _Range) {
         _Orphan_all();
@@ -837,7 +837,7 @@ public:
         }
         _Guard._Container = nullptr;
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     iterator insert(const_iterator _Where, _Ty&& _Val) {
         return emplace(_Where, _STD move(_Val));
@@ -1240,12 +1240,12 @@ public:
         _Assign_range(_Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void assign_range(_Rng&& _Range) {
         _Assign_range(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void assign(_CRT_GUARDOVERFLOW size_type _Count, const _Ty& _Val) { // assign _Count * _Val
         _Orphan_all();
@@ -1381,7 +1381,7 @@ public:
             _Off, _Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     iterator insert_range(const_iterator _Where, _Rng&& _Range) {
         const size_type _Off = static_cast<size_type>(_Where - begin());
@@ -1393,7 +1393,7 @@ public:
             return _Insert_range<_Is_bidi::_No>(_Off, _RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     iterator erase(const_iterator _Where) noexcept(is_nothrow_move_assignable_v<value_type>) /* strengthened */ {
         return erase(_Where, _Next_iter(_Where));
@@ -1690,11 +1690,11 @@ template <class _Iter, class _Alloc = allocator<_Iter_value_t<_Iter>>,
 deque(_Iter, _Iter, _Alloc = _Alloc()) -> deque<_Iter_value_t<_Iter>, _Alloc>;
 #endif // _HAS_CXX17
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 deque(from_range_t, _Rng&&, _Alloc = _Alloc()) -> deque<_RANGES range_value_t<_Rng>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 template <class _Ty, class _Alloc>
 void swap(deque<_Ty, _Alloc>& _Left, deque<_Ty, _Alloc>& _Right) noexcept /* strengthened */ {
diff --git a/stl/inc/expected b/stl/inc/expected
index be5a614f80..20894ab5a3 100644
--- a/stl/inc/expected
+++ b/stl/inc/expected
@@ -8,9 +8,9 @@
 #define _EXPECTED_
 #include <yvals.h>
 #if _STL_COMPILER_PREPROCESSOR
-#ifndef __cpp_lib_expected
+#if !_HAS_CXX23 || !defined(__cpp_lib_concepts) // TRANSITION, GH-395
 _EMIT_STL_WARNING(STL4038, "The contents of <expected> are available only with C++23 or later.");
-#else // ^^^ !__cpp_lib_expected / __cpp_lib_expected vvv
+#else // ^^^ not supported / supported language mode vvv
 #include <exception>
 #include <initializer_list>
 #include <type_traits>
@@ -1083,6 +1083,6 @@ _STD_END
 _STL_RESTORE_CLANG_WARNINGS
 #pragma warning(pop)
 #pragma pack(pop)
-#endif // __cpp_lib_expected
+#endif // ^^^ supported language mode ^^^
 #endif // _STL_COMPILER_PREPROCESSOR
 #endif // _EXPECTED_
diff --git a/stl/inc/format b/stl/inc/format
index 5413dc3b6d..cf26ca191f 100644
--- a/stl/inc/format
+++ b/stl/inc/format
@@ -39,9 +39,9 @@
 #define _FORMAT_
 #include <yvals_core.h>
 #if _STL_COMPILER_PREPROCESSOR
-#ifndef __cpp_lib_format
+#ifndef __cpp_lib_concepts
 _EMIT_STL_WARNING(STL4038, "The contents of <format> are available only with C++20 or later.");
-#else // ^^^ !defined(__cpp_lib_format) / defined(__cpp_lib_format) vvv
+#else // ^^^ !defined(__cpp_lib_concepts) / defined(__cpp_lib_concepts) vvv
 
 #include <__msvc_format_ucd_tables.hpp>
 #include <algorithm>
@@ -3606,6 +3606,6 @@ _STL_RESTORE_CLANG_WARNINGS
 #pragma warning(pop)
 #pragma pack(pop)
 
-#endif // __cpp_lib_format
+#endif // __cpp_lib_concepts
 #endif // _STL_COMPILER_PREPROCESSOR
 #endif // _FORMAT_
diff --git a/stl/inc/forward_list b/stl/inc/forward_list
index 8e8330c60a..77e35f6df3 100644
--- a/stl/inc/forward_list
+++ b/stl/inc/forward_list
@@ -607,7 +607,7 @@ public:
         _Insert_op._Attach_after(_Mypair._Myval2._Before_head());
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     forward_list(from_range_t, _Rng&& _Range) : _Mypair(_Zero_then_variadic_args_t{}) {
         _Flist_insert_after_op2<_Alnode> _Insert_op(_Getal());
@@ -623,7 +623,7 @@ public:
         _Alloc_proxy();
         _Insert_op._Attach_after(_Mypair._Myval2._Before_head());
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     forward_list(forward_list&& _Right) noexcept // strengthened
         : _Mypair(_One_then_variadic_args_t{}, _STD move(_Right._Getal())) {
@@ -915,12 +915,12 @@ public:
         _Insert_after(_Mypair._Myval2._Before_head(), _Val);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void prepend_range(_Rng&& _Range) {
         _Insert_range_after(_Mypair._Myval2._Before_head(), _RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void pop_front() noexcept /* strengthened */ {
         _Erase_after(_Mypair._Myval2._Before_head());
@@ -960,12 +960,12 @@ public:
         _Assign_unchecked(_Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void assign_range(_Rng&& _Range) {
         _Assign_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void assign(_CRT_GUARDOVERFLOW size_type _Count, const _Ty& _Val) {
         clear();
@@ -1022,7 +1022,7 @@ public:
         return _Insert_range_after(_Where._Ptr, _Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     iterator insert_range_after(const_iterator _Where, _Rng&& _Range) {
 #if _ITERATOR_DEBUG_LEVEL == 2
@@ -1031,7 +1031,7 @@ public:
 #endif // _ITERATOR_DEBUG_LEVEL == 2
         return _Insert_range_after(_Where._Ptr, _RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 private:
     void _Erase_after(_Nodeptr _Pnode) noexcept { // erase element after _Pnode
@@ -1555,11 +1555,11 @@ template <class _Iter, class _Alloc = allocator<_Iter_value_t<_Iter>>,
 forward_list(_Iter, _Iter, _Alloc = _Alloc()) -> forward_list<_Iter_value_t<_Iter>, _Alloc>;
 #endif // _HAS_CXX17
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 forward_list(from_range_t, _Rng&&, _Alloc = _Alloc()) -> forward_list<_RANGES range_value_t<_Rng>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 template <class _Ty, class _Alloc>
 void swap(forward_list<_Ty, _Alloc>& _Left, forward_list<_Ty, _Alloc>& _Right) noexcept /* strengthened */ {
diff --git a/stl/inc/list b/stl/inc/list
index f997f83adf..fedc6b540d 100644
--- a/stl/inc/list
+++ b/stl/inc/list
@@ -882,7 +882,7 @@ public:
         _Construct_range_unchecked(_Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     list(from_range_t, _Rng&& _Range) : _Mypair(_Zero_then_variadic_args_t{}) {
         _Construct_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -892,7 +892,7 @@ public:
     list(from_range_t, _Rng&& _Range, const _Alloc& _Al) : _Mypair(_One_then_variadic_args_t{}, _Al) {
         _Construct_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     list(list&& _Right) : _Mypair(_One_then_variadic_args_t{}, _STD move(_Right._Getal())) {
         _Alloc_sentinel_and_proxy();
@@ -1235,14 +1235,14 @@ public:
         _Emplace(_Mypair._Myval2._Myhead->_Next, _Val);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void prepend_range(_Rng&& _Range) {
         _List_node_insert_op2<_Alnode> _Op(_Getal());
         _Op._Append_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         _Op._Attach_before(_Mypair._Myval2, _Mypair._Myval2._Myhead->_Next);
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void pop_front() noexcept /* strengthened */ {
 #if _CONTAINER_DEBUG_LEVEL > 0
@@ -1256,14 +1256,14 @@ public:
         _Emplace(_Mypair._Myval2._Myhead, _Val);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void append_range(_Rng&& _Range) {
         _List_node_insert_op2<_Alnode> _Op(_Getal());
         _Op._Append_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         _Op._Attach_at_end(_Mypair._Myval2);
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void pop_back() noexcept /* strengthened */ {
 #if _CONTAINER_DEBUG_LEVEL > 0
@@ -1333,12 +1333,12 @@ public:
         _Assign_unchecked(_Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void assign_range(_Rng&& _Range) {
         _Assign_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void assign(_CRT_GUARDOVERFLOW size_type _Count, const _Ty& _Val) { // assign _Count * _Val
         const auto _Myend = _Mypair._Myval2._Myhead;
@@ -1392,7 +1392,7 @@ public:
         return _Make_iter(_Op._Attach_before(_Mypair._Myval2, _Where._Ptr));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     iterator insert_range(const_iterator _Where, _Rng&& _Range) {
 #if _ITERATOR_DEBUG_LEVEL == 2
@@ -1402,7 +1402,7 @@ public:
         _Op._Append_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         return _Make_iter(_Op._Attach_before(_Mypair._Myval2, _Where._Ptr));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     iterator erase(const const_iterator _Where) noexcept /* strengthened */ {
 #if _ITERATOR_DEBUG_LEVEL == 2
@@ -1858,11 +1858,11 @@ template <class _Iter, class _Alloc = allocator<_Iter_value_t<_Iter>>,
 list(_Iter, _Iter, _Alloc = _Alloc()) -> list<_Iter_value_t<_Iter>, _Alloc>;
 #endif // _HAS_CXX17
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 list(from_range_t, _Rng&&, _Alloc = _Alloc()) -> list<_RANGES range_value_t<_Rng>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 template <class _Ty, class _Alloc>
 void swap(list<_Ty, _Alloc>& _Left, list<_Ty, _Alloc>& _Right) noexcept /* strengthened */ {
diff --git a/stl/inc/map b/stl/inc/map
index 30da92584f..e2cbb000d5 100644
--- a/stl/inc/map
+++ b/stl/inc/map
@@ -134,7 +134,7 @@ public:
         insert(_First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     map(from_range_t, _Rng&& _Range) : _Mybase(key_compare()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -154,7 +154,7 @@ public:
     map(from_range_t, _Rng&& _Range, const allocator_type& _Al) : _Mybase(key_compare(), _Al) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     map& operator=(const map& _Right) {
         _Mybase::operator=(_Right);
@@ -382,7 +382,7 @@ map(_Iter, _Iter, _Alloc) -> map<_Guide_key_t<_Iter>, _Guide_val_t<_Iter>, less<
 template <class _Kty, class _Ty, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 map(initializer_list<pair<_Kty, _Ty>>, _Alloc) -> map<_Kty, _Ty, less<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Pr = less<_Range_key_type<_Rng>>,
     class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
     enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -392,7 +392,7 @@ map(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc())
 template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 map(from_range_t, _Rng&&, _Alloc)
     -> map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, less<_Range_key_type<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Ty, class _Pr, class _Alloc>
@@ -512,7 +512,7 @@ public:
         insert(_First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     multimap(from_range_t, _Rng&& _Range) : _Mybase(key_compare()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -532,7 +532,7 @@ public:
     multimap(from_range_t, _Rng&& _Range, const allocator_type& _Al) : _Mybase(key_compare(), _Al) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     multimap& operator=(const multimap& _Right) {
         _Mybase::operator=(_Right);
@@ -613,7 +613,7 @@ multimap(_Iter, _Iter, _Alloc) -> multimap<_Guide_key_t<_Iter>, _Guide_val_t<_It
 template <class _Kty, class _Ty, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 multimap(initializer_list<pair<_Kty, _Ty>>, _Alloc) -> multimap<_Kty, _Ty, less<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Pr = less<_Range_key_type<_Rng>>,
     class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
     enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -623,7 +623,7 @@ multimap(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc())
 template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 multimap(from_range_t, _Rng&&, _Alloc)
     -> multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, less<_Range_key_type<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Ty, class _Pr, class _Alloc>
diff --git a/stl/inc/queue b/stl/inc/queue
index c83a66d595..229c1ef1b5 100644
--- a/stl/inc/queue
+++ b/stl/inc/queue
@@ -12,9 +12,9 @@
 #include <deque>
 #include <vector>
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 #include <ranges>
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
@@ -47,10 +47,10 @@ public:
     queue(_InIt _First, _InIt _Last) noexcept(is_nothrow_constructible_v<_Container, _InIt, _InIt>) // strengthened
         : c(_STD move(_First), _STD move(_Last)) {}
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
     template <_Container_compatible_range<_Ty> _Rng>
     queue(from_range_t, _Rng&& _Range) : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range))) {}
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 
     template <class _Alloc, enable_if_t<uses_allocator_v<_Container, _Alloc>, int> = 0>
@@ -80,11 +80,11 @@ public:
         is_nothrow_constructible_v<_Container, _InIt, _InIt, const _Alloc&>) // strengthened
         : c(_STD move(_First), _STD move(_Last), _Al) {}
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
     template <_Container_compatible_range<_Ty> _Rng, class _Alloc>
     queue(from_range_t, _Rng&& _Range, const _Alloc& _Al)
         : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range), _Al)) {}
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 
     _NODISCARD bool empty() const noexcept(noexcept(c.empty())) /* strengthened */ {
@@ -119,7 +119,7 @@ public:
         c.push_back(_STD move(_Val));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void push_range(_Rng&& _Range) {
         if constexpr (requires { c.append_range(_Range); }) {
@@ -128,7 +128,7 @@ public:
             _RANGES copy(_Range, back_insert_iterator{c});
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     template <class... _Valty>
     decltype(auto) emplace(_Valty&&... _Val) {
@@ -169,12 +169,12 @@ template <class _InIt, class _Alloc = allocator<_Iter_value_t<_InIt>>,
     enable_if_t<conjunction_v<_Is_iterator<_InIt>, _Is_allocator<_Alloc>>, int> = 0>
 queue(_InIt, _InIt, _Alloc = _Alloc()) -> queue<_Iter_value_t<_InIt>, deque<_Iter_value_t<_InIt>, _Alloc>>;
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
 template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 queue(from_range_t, _Rng&&, _Alloc = _Alloc())
     -> queue<_RANGES range_value_t<_Rng>, deque<_RANGES range_value_t<_Rng>, _Alloc>>;
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 
 template <class _Ty, class _Container>
@@ -271,13 +271,13 @@ public:
         _STD make_heap(c.begin(), c.end(), comp);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     priority_queue(from_range_t, _Rng&& _Range, const _Pr& _Pred = _Pr())
         : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range))), comp(_Pred) {
         _STD make_heap(c.begin(), c.end(), comp);
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     template <class _Alloc, enable_if_t<uses_allocator_v<_Container, _Alloc>, int> = 0>
     explicit priority_queue(const _Alloc& _Al) noexcept(is_nothrow_constructible_v<_Container, const _Alloc&>&&
@@ -337,7 +337,7 @@ public:
         _STD make_heap(c.begin(), c.end(), comp);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng, class _Alloc,
         enable_if_t<uses_allocator_v<_Container, _Alloc>, int> = 0>
     priority_queue(from_range_t, _Rng&& _Range, const _Pr& _Pred, const _Alloc& _Al)
@@ -351,7 +351,7 @@ public:
         : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range), _Al)), comp() {
         _STD make_heap(c.begin(), c.end(), comp);
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _NODISCARD bool empty() const noexcept(noexcept(c.empty())) /* strengthened */ {
         return c.empty();
@@ -375,7 +375,7 @@ public:
         _STD push_heap(c.begin(), c.end(), comp);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void push_range(_Rng&& _Range) { // per LWG-3723
         if constexpr (requires { c.append_range(_Range); }) {
@@ -386,7 +386,7 @@ public:
 
         _STD make_heap(c.begin(), c.end(), comp);
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     template <class... _Valty>
     void emplace(_Valty&&... _Val) {
@@ -440,7 +440,7 @@ template <class _Iter, class _Compare, class _Container, class _Alloc,
 priority_queue(_Iter, _Iter, _Compare, _Container, _Alloc)
     -> priority_queue<typename _Container::value_type, _Container, _Compare>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Pr = less<_RANGES range_value_t<_Rng>>,
     enable_if_t<!_Is_allocator<_Pr>::value, int> = 0>
 priority_queue(from_range_t, _Rng&&, _Pr = _Pr())
@@ -454,7 +454,7 @@ priority_queue(from_range_t, _Rng&&, _Pr, _Alloc)
 template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 priority_queue(from_range_t, _Rng&&, _Alloc)
     -> priority_queue<_RANGES range_value_t<_Rng>, vector<_RANGES range_value_t<_Rng>, _Alloc>>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Ty, class _Container, class _Pr,
diff --git a/stl/inc/set b/stl/inc/set
index a7ab8aef22..74055ed107 100644
--- a/stl/inc/set
+++ b/stl/inc/set
@@ -111,7 +111,7 @@ public:
         this->insert(_First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     set(from_range_t, _Rng&& _Range) : _Mybase(key_compare()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -131,7 +131,7 @@ public:
     set(from_range_t, _Rng&& _Range, const allocator_type& _Al) : _Mybase(key_compare(), _Al) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     set& operator=(const set& _Right) {
         _Mybase::operator=(_Right);
@@ -193,7 +193,7 @@ set(_Iter, _Iter, _Alloc) -> set<_Iter_value_t<_Iter>, less<_Iter_value_t<_Iter>
 template <class _Kty, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 set(initializer_list<_Kty>, _Alloc) -> set<_Kty, less<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Pr = less<_RANGES range_value_t<_Rng>>,
     class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -201,7 +201,7 @@ set(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc()) -> set<_RANGES range_v
 
 template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 set(from_range_t, _Rng&&, _Alloc) -> set<_RANGES range_value_t<_Rng>, less<_RANGES range_value_t<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Pr, class _Alloc>
@@ -319,7 +319,7 @@ public:
         this->insert(_First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     multiset(from_range_t, _Rng&& _Range) : _Mybase(key_compare()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -339,7 +339,7 @@ public:
     multiset(from_range_t, _Rng&& _Range, const allocator_type& _Al) : _Mybase(key_compare(), _Al) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     multiset& operator=(const multiset& _Right) {
         _Mybase::operator=(_Right);
@@ -407,7 +407,7 @@ multiset(_Iter, _Iter, _Alloc) -> multiset<_Iter_value_t<_Iter>, less<_Iter_valu
 template <class _Kty, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 multiset(initializer_list<_Kty>, _Alloc) -> multiset<_Kty, less<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Pr = less<_RANGES range_value_t<_Rng>>,
     class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<conjunction_v<negation<_Is_allocator<_Pr>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -416,7 +416,7 @@ multiset(from_range_t, _Rng&&, _Pr = _Pr(), _Alloc = _Alloc()) -> multiset<_RANG
 template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 multiset(from_range_t, _Rng&&, _Alloc)
     -> multiset<_RANGES range_value_t<_Rng>, less<_RANGES range_value_t<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Pr, class _Alloc>
diff --git a/stl/inc/stack b/stl/inc/stack
index dbc01a8e88..85bb24772b 100644
--- a/stl/inc/stack
+++ b/stl/inc/stack
@@ -10,9 +10,9 @@
 #if _STL_COMPILER_PREPROCESSOR
 #include <deque>
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 #include <ranges>
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 #pragma pack(push, _CRT_PACKING)
 #pragma warning(push, _STL_WARNING_LEVEL)
@@ -45,10 +45,10 @@ public:
     stack(_InIt _First, _InIt _Last) noexcept(is_nothrow_constructible_v<_Container, _InIt, _InIt>) // strengthened
         : c(_STD move(_First), _STD move(_Last)) {}
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
     template <_Container_compatible_range<_Ty> _Rng>
     stack(from_range_t, _Rng&& _Range) : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range))) {}
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 
     template <class _Alloc, enable_if_t<uses_allocator_v<_Container, _Alloc>, int> = 0>
@@ -78,11 +78,11 @@ public:
         is_nothrow_constructible_v<_Container, _InIt, _InIt, const _Alloc&>) // strengthened
         : c(_STD move(_First), _STD move(_Last), _Al) {}
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
     template <_Container_compatible_range<_Ty> _Rng, class _Alloc>
     stack(from_range_t, _Rng&& _Range, const _Alloc& _Al)
         : c(_RANGES to<_Container>(_STD forward<_Rng>(_Range), _Al)) {}
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 
     _NODISCARD bool empty() const noexcept(noexcept(c.empty())) /* strengthened */ {
@@ -109,7 +109,7 @@ public:
         c.push_back(_STD move(_Val));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     void push_range(_Rng&& _Range) {
         if constexpr (requires { c.append_range(_Range); }) {
@@ -118,7 +118,7 @@ public:
             _RANGES copy(_Range, back_insert_iterator{c});
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     template <class... _Valty>
     decltype(auto) emplace(_Valty&&... _Val) {
@@ -159,13 +159,13 @@ template <class _InIt, class _Alloc = allocator<_Iter_value_t<_InIt>>,
     enable_if_t<conjunction_v<_Is_iterator<_InIt>, _Is_allocator<_Alloc>>, int> = 0>
 stack(_InIt, _InIt, _Alloc = _Alloc()) -> stack<_Iter_value_t<_InIt>, deque<_Iter_value_t<_InIt>, _Alloc>>;
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
 template <_RANGES input_range _Rng>
 stack(from_range_t, _Rng&&) -> stack<_RANGES range_value_t<_Rng>>;
 
 template <_RANGES input_range _Rng, class _Alloc, enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 stack(from_range_t, _Rng&&, _Alloc) -> stack<_RANGES range_value_t<_Rng>, deque<_RANGES range_value_t<_Rng>, _Alloc>>;
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 
 template <class _Ty, class _Container>
diff --git a/stl/inc/system_error b/stl/inc/system_error
index 3062902c6d..9a6609a05c 100644
--- a/stl/inc/system_error
+++ b/stl/inc/system_error
@@ -71,10 +71,7 @@ public:
         _Addr = reinterpret_cast<uintptr_t>(this);
     }
 
-#ifdef __cpp_constexpr_dynamic_alloc
-    constexpr
-#endif
-        virtual ~error_category() noexcept = default;
+    _CONSTEXPR20 virtual ~error_category() noexcept = default;
 
     _NODISCARD virtual const char* name() const noexcept = 0;
 
@@ -566,8 +563,8 @@ public:
 // * can't use magic statics in standard modes, because that would inject a .TLS section into all binaries using
 //   <system_error> and would likely put borderline programs over the TLS slot count limit, and would destroy the
 //   variable during DLL unload
-// * can't declare the error_category as an ordinary constexpr variable for most compilers, because error_category
-//   has a virtual destructor (TRANSITION, __cpp_constexpr_dynamic_alloc)
+// * can't declare the error_category as an ordinary constexpr variable for most compilers before C++20, because
+//   error_category has a virtual destructor
 // * can't declare the error_category as an ordinary non-constexpr variable even with a constexpr constructor, because
 //   the compiler will emit code to destroy it which invalidates its use in these DLL shutdown scenarios
 //
@@ -594,7 +591,7 @@ _NODISCARD const _Ty& _Immortalize_memcpy_image() noexcept {
     /* MAGIC */ static _Immortalizer_impl<_Ty> _Static;
     return _Static._Storage;
 }
-#elif defined(__cpp_constexpr_dynamic_alloc)
+#elif _HAS_CXX20
 template <class _Ty>
 _NODISCARD const _Ty& _Immortalize_memcpy_image() noexcept {
     static constexpr _Ty _Static;
diff --git a/stl/inc/unordered_map b/stl/inc/unordered_map
index 4fca6fd7e2..dac3da6c94 100644
--- a/stl/inc/unordered_map
+++ b/stl/inc/unordered_map
@@ -190,7 +190,7 @@ public:
         insert(_First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     unordered_map(from_range_t, _Rng&& _Range) : _Mybase(_Key_compare(), allocator_type()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -242,7 +242,7 @@ public:
         _Mybase::rehash(_Buckets);
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     unordered_map& operator=(const unordered_map& _Right) {
         _Mybase::operator=(_Right);
@@ -499,7 +499,7 @@ template <class _Kty, class _Ty, class _Hasher, class _Alloc,
 unordered_map(initializer_list<pair<_Kty, _Ty>>, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_map<_Kty, _Ty, _Hasher, equal_to<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Hasher = hash<_Range_key_type<_Rng>>,
     class _Keyeq = equal_to<_Range_key_type<_Rng>>, class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
     enable_if_t<conjunction_v<_Is_hasher<_Hasher>, negation<_Is_allocator<_Keyeq>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -518,7 +518,7 @@ template <_RANGES input_range _Rng, class _Hasher, class _Alloc,
     enable_if_t<conjunction_v<_Is_hasher<_Hasher>, _Is_allocator<_Alloc>>, int> = 0>
 unordered_map(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_map<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Hasher, equal_to<_Range_key_type<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Ty, class _Hasher, class _Keyeq, class _Alloc>
@@ -674,7 +674,7 @@ public:
         insert(_First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     unordered_multimap(from_range_t, _Rng&& _Range) : _Mybase(_Key_compare(), allocator_type()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -727,7 +727,7 @@ public:
         _Mybase::rehash(_Buckets);
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     unordered_multimap& operator=(const unordered_multimap& _Right) {
         _Mybase::operator=(_Right);
@@ -866,7 +866,7 @@ template <class _Kty, class _Ty, class _Hasher, class _Alloc,
 unordered_multimap(initializer_list<pair<_Kty, _Ty>>, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_multimap<_Kty, _Ty, _Hasher, equal_to<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Hasher = hash<_Range_key_type<_Rng>>,
     class _Keyeq = equal_to<_Range_key_type<_Rng>>, class _Alloc = allocator<_Range_to_alloc_type<_Rng>>,
     enable_if_t<conjunction_v<_Is_hasher<_Hasher>, negation<_Is_allocator<_Keyeq>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -887,7 +887,7 @@ template <_RANGES input_range _Rng, class _Hasher, class _Alloc,
 unordered_multimap(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_multimap<_Range_key_type<_Rng>, _Range_mapped_type<_Rng>, _Hasher, equal_to<_Range_key_type<_Rng>>,
         _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Ty, class _Hasher, class _Keyeq, class _Alloc>
diff --git a/stl/inc/unordered_set b/stl/inc/unordered_set
index c54eafea51..ff6d96110c 100644
--- a/stl/inc/unordered_set
+++ b/stl/inc/unordered_set
@@ -184,7 +184,7 @@ public:
         this->insert(_First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     unordered_set(from_range_t, _Rng&& _Range) : _Mybase(_Key_compare(), allocator_type()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -236,7 +236,7 @@ public:
         _Mybase::rehash(_Buckets);
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     unordered_set& operator=(const unordered_set& _Right) {
         _Mybase::operator=(_Right);
@@ -353,7 +353,7 @@ template <class _Kty, class _Hasher, class _Alloc,
 unordered_set(initializer_list<_Kty>, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_set<_Kty, _Hasher, equal_to<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Hasher = hash<_RANGES range_value_t<_Rng>>,
     class _Keyeq = equal_to<_RANGES range_value_t<_Rng>>, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<conjunction_v<_Is_hasher<_Hasher>, negation<_Is_allocator<_Keyeq>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -372,7 +372,7 @@ template <_RANGES input_range _Rng, class _Hasher, class _Alloc,
     enable_if_t<conjunction_v<_Is_hasher<_Hasher>, _Is_allocator<_Alloc>>, int> = 0>
 unordered_set(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_set<_RANGES range_value_t<_Rng>, _Hasher, equal_to<_RANGES range_value_t<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Hasher, class _Keyeq, class _Alloc>
@@ -530,7 +530,7 @@ public:
 
     unordered_multiset(unordered_multiset&& _Right, const allocator_type& _Al) : _Mybase(_STD move(_Right), _Al) {}
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     unordered_multiset(from_range_t, _Rng&& _Range) : _Mybase(_Key_compare(), allocator_type()) {
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
@@ -583,7 +583,7 @@ public:
         _Mybase::rehash(_Buckets);
         this->_Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     unordered_multiset& operator=(unordered_multiset&& _Right) noexcept(_Alnode_traits::is_always_equal::value&&
             is_nothrow_move_assignable_v<_Hasher>&& is_nothrow_move_assignable_v<_Keyeq>) {
@@ -692,7 +692,7 @@ template <class _Kty, class _Hasher, class _Alloc,
 unordered_multiset(initializer_list<_Kty>, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_multiset<_Kty, _Hasher, equal_to<_Kty>, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Hasher = hash<_RANGES range_value_t<_Rng>>,
     class _Keyeq = equal_to<_RANGES range_value_t<_Rng>>, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<conjunction_v<_Is_hasher<_Hasher>, negation<_Is_allocator<_Keyeq>>, _Is_allocator<_Alloc>>, int> = 0>
@@ -712,7 +712,7 @@ template <_RANGES input_range _Rng, class _Hasher, class _Alloc,
     enable_if_t<conjunction_v<_Is_hasher<_Hasher>, _Is_allocator<_Alloc>>, int> = 0>
 unordered_multiset(from_range_t, _Rng&&, _Guide_size_type_t<_Alloc>, _Hasher, _Alloc)
     -> unordered_multiset<_RANGES range_value_t<_Rng>, _Hasher, equal_to<_RANGES range_value_t<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Kty, class _Hasher, class _Keyeq, class _Alloc>
diff --git a/stl/inc/vector b/stl/inc/vector
index 4f40a9e7f0..1cc9d835f8 100644
--- a/stl/inc/vector
+++ b/stl/inc/vector
@@ -721,7 +721,7 @@ public:
         _Construct_n(_Convert_size<size_type>(_Ilist.size()), _Ilist.begin(), _Ilist.end());
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     constexpr vector(from_range_t, _Rng&& _Range, const _Alloc& _Al = _Alloc())
         : _Mypair(_One_then_variadic_args_t{}, _Al) {
@@ -740,7 +740,7 @@ public:
             _Proxy._Release();
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 vector(const vector& _Right)
         : _Mypair(_One_then_variadic_args_t{}, _Alty_traits::select_on_container_copy_construction(_Right._Getal())) {
@@ -955,7 +955,7 @@ private:
         }
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <class _Iter>
     _CONSTEXPR20 void _Append_counted_range(_Iter _First, const size_type _Count) {
         // insert counted range _First + [0, _Count) at end
@@ -1012,10 +1012,10 @@ private:
             _Orphan_range(_Oldlast, _Oldlast);
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 public:
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     constexpr void append_range(_Rng&& _Range) {
         if constexpr (_RANGES forward_range<_Rng> || _RANGES sized_range<_Rng>) {
@@ -1026,7 +1026,7 @@ public:
             _Append_uncounted_range(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     template <class... _Valty>
     _CONSTEXPR20 iterator emplace(const_iterator _Where, _Valty&&... _Val) {
@@ -1316,7 +1316,7 @@ public:
         return _Make_iterator_offset(_Whereoff);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     constexpr iterator insert_range(const_iterator _Where, _Rng&& _Range) {
         const pointer _Whereptr = _Where._Ptr;
@@ -1338,7 +1338,7 @@ public:
         }
         return _Make_iterator_offset(_Whereoff);
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 iterator insert(const_iterator _Where, initializer_list<_Ty> _Ilist) {
         const pointer _Whereptr = _Where._Ptr;
@@ -1524,7 +1524,7 @@ public:
         }
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Ty> _Rng>
     constexpr void assign_range(_Rng&& _Range) {
         if constexpr (_RANGES sized_range<_Rng> || _RANGES forward_range<_Rng>) {
@@ -1535,7 +1535,7 @@ public:
             _Assign_uncounted_range(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 void assign(const initializer_list<_Ty> _Ilist) {
         const auto _Count = _Convert_size<size_type>(_Ilist.size());
@@ -2267,11 +2267,11 @@ template <class _Iter, class _Alloc = allocator<_Iter_value_t<_Iter>>,
 vector(_Iter, _Iter, _Alloc = _Alloc()) -> vector<_Iter_value_t<_Iter>, _Alloc>;
 #endif // _HAS_CXX17
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 vector(from_range_t, _Rng&&, _Alloc = _Alloc()) -> vector<_RANGES range_value_t<_Rng>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 template <class _Alloc>
 class vector<bool, _Alloc>;
@@ -2967,7 +2967,7 @@ public:
         insert(begin(), _First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<bool> _Rng>
     constexpr vector(from_range_t, _Rng&& _Range, const _Alloc& _Al = _Alloc()) : _Mybase(_Al) {
         if constexpr (_RANGES forward_range<_Rng> || _RANGES sized_range<_Rng>) {
@@ -2978,7 +2978,7 @@ public:
             _Assign_uncounted_range(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 vector(vector&& _Right) noexcept(is_nothrow_move_constructible_v<_Mybase>) // strengthened
         : _Mybase(_STD move(_Right)) {
@@ -3304,12 +3304,12 @@ public:
         insert(end(), _Val);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<bool> _Rng>
     constexpr void append_range(_Rng&& _Range) {
         insert_range(end(), _STD forward<_Rng>(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 void pop_back() noexcept /* strengthened */ {
         erase(end() - 1);
@@ -3321,7 +3321,7 @@ public:
         insert(begin(), _First, _Last);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <class _Iter>
     constexpr void _Assign_counted_range(_Iter _First, const size_type _Count) {
         _STL_INTERNAL_CHECK(this->_Myvec.empty());
@@ -3379,7 +3379,7 @@ public:
             _Assign_uncounted_range(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 void assign(_CRT_GUARDOVERFLOW size_type _Count, const bool& _Val) {
         clear();
@@ -3427,7 +3427,7 @@ public:
         return begin() + _Saved_offset;
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<bool> _Rng>
     constexpr iterator insert_range(const_iterator _Where, _Rng&& _Range) {
         const difference_type _Old_off = _Where - begin();
@@ -3452,7 +3452,7 @@ public:
 
         return begin() + _Old_off;
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 iterator erase(const_iterator _Where_arg) noexcept /* strengthened */ {
         iterator _Where      = _Make_iter(_Where_arg);
diff --git a/stl/inc/xhash b/stl/inc/xhash
index e19dcfed5a..9b58de3739 100644
--- a/stl/inc/xhash
+++ b/stl/inc/xhash
@@ -960,12 +960,12 @@ public:
         _Insert_range_unchecked(_Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     void insert_range(_Rng&& _Range) {
         _Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void insert(initializer_list<value_type> _Ilist) {
         _Insert_range_unchecked(_Ilist.begin(), _Ilist.end());
diff --git a/stl/inc/xmemory b/stl/inc/xmemory
index 3236045ec9..62eeda578f 100644
--- a/stl/inc/xmemory
+++ b/stl/inc/xmemory
@@ -2317,7 +2317,7 @@ constexpr _Ty* uninitialized_construct_using_allocator(_Ty* _Ptr, const _Alloc&
 }
 #endif // _HAS_CXX20
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 struct from_range_t {
     explicit from_range_t() = default;
 };
@@ -2336,7 +2336,7 @@ using _Range_mapped_type = typename _RANGES range_value_t<_Rng>::second_type;
 template <_RANGES input_range _Rng>
 using _Range_to_alloc_type =
     pair<const typename _RANGES range_value_t<_Rng>::first_type, typename _RANGES range_value_t<_Rng>::second_type>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 template <class _Ty,
     bool = is_empty_v<_Ty> && !is_final_v<_Ty>>
diff --git a/stl/inc/xstring b/stl/inc/xstring
index 41302d912d..2a91996e6d 100644
--- a/stl/inc/xstring
+++ b/stl/inc/xstring
@@ -2417,11 +2417,11 @@ _INLINE_VAR constexpr bool _Has_minimum_allocation_alignment_string<_String,
 #pragma detect_mismatch("annotate_string", "0")
 #endif // !_INSERT_STRING_ANNOTATION
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <class _Rng, class _Ty>
 concept _Contiguous_range_of =
     _RANGES contiguous_range<_Rng> && same_as<remove_cvref_t<_RANGES range_reference_t<_Rng>>, _Ty>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
 template <class _Elem, class _Traits = char_traits<_Elem>, class _Alloc = allocator<_Elem>>
 class basic_string { // null-terminated transparent array of elements
@@ -2836,7 +2836,7 @@ private:
     }
 
 public:
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Elem> _Rng>
     constexpr basic_string(from_range_t, _Rng&& _Range, const _Alloc& _Al = _Alloc())
         : _Mypair(_One_then_variadic_args_t{}, _Al) {
@@ -2852,7 +2852,7 @@ public:
             _Construct_from_iter(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 basic_string(basic_string&& _Right) noexcept
         : _Mypair(_One_then_variadic_args_t{}, _STD move(_Right._Getal())) {
@@ -3428,7 +3428,7 @@ public:
         }
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Elem> _Rng>
     constexpr basic_string& append_range(_Rng&& _Range) {
         if constexpr (_RANGES sized_range<_Rng> && _Contiguous_range_of<_Rng, _Elem>) {
@@ -3439,7 +3439,7 @@ public:
             return append(_Right._Mypair._Myval2._Myptr(), _Right._Mypair._Myval2._Mysize);
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 basic_string& assign(const basic_string& _Right) {
         *this = _Right;
@@ -3533,7 +3533,7 @@ public:
         }
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Elem> _Rng>
     constexpr basic_string& assign_range(_Rng&& _Range) {
         if constexpr (_RANGES sized_range<_Rng> && _Contiguous_range_of<_Rng, _Elem>) {
@@ -3550,7 +3550,7 @@ public:
             }
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 basic_string& insert(const size_type _Off, const basic_string& _Right) {
         // insert _Right at _Off
@@ -3702,7 +3702,7 @@ public:
         return begin() + static_cast<difference_type>(_Off);
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Elem> _Rng>
     constexpr iterator insert_range(const const_iterator _Where, _Rng&& _Range) {
 #if _ITERATOR_DEBUG_LEVEL != 0
@@ -3720,7 +3720,7 @@ public:
 
         return begin() + static_cast<difference_type>(_Off);
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _CONSTEXPR20 basic_string& erase(const size_type _Off = 0) { // erase elements [_Off, ...)
         _Mypair._Myval2._Check_offset(_Off);
@@ -3986,7 +3986,7 @@ public:
         }
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<_Elem> _Rng>
     constexpr basic_string& replace_with_range(const const_iterator _First, const const_iterator _Last, _Rng&& _Range) {
         _Adl_verify_range(_First, _Last);
@@ -4004,7 +4004,7 @@ public:
             return replace(_Off, _Length, _Right._Mypair._Myval2._Myptr(), _Right._Mypair._Myval2._Mysize);
         }
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     _NODISCARD _CONSTEXPR20 iterator begin() noexcept {
         return iterator(_Refancy<pointer>(_Mypair._Myval2._Myptr()), _STD addressof(_Mypair._Myval2));
@@ -4991,12 +4991,12 @@ template <class _Elem, class _Traits, class _Alloc = allocator<_Elem>,
 basic_string(basic_string_view<_Elem, _Traits>, _Guide_size_type_t<_Alloc>, _Guide_size_type_t<_Alloc>,
     const _Alloc& = _Alloc()) -> basic_string<_Elem, _Traits, _Alloc>;
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 template <_RANGES input_range _Rng, class _Alloc = allocator<_RANGES range_value_t<_Rng>>,
     enable_if_t<_Is_allocator<_Alloc>::value, int> = 0>
 basic_string(from_range_t, _Rng&&, _Alloc = _Alloc())
     -> basic_string<_RANGES range_value_t<_Rng>, char_traits<_RANGES range_value_t<_Rng>>, _Alloc>;
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 #endif // _HAS_CXX17
 
 template <class _Elem, class _Traits, class _Alloc>
diff --git a/stl/inc/xtree b/stl/inc/xtree
index dc73aa2f91..b43e6bbd16 100644
--- a/stl/inc/xtree
+++ b/stl/inc/xtree
@@ -1268,12 +1268,12 @@ public:
         _Insert_range_unchecked(_Get_unwrapped(_First), _Get_unwrapped(_Last));
     }
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     template <_Container_compatible_range<value_type> _Rng>
     void insert_range(_Rng&& _Range) {
         _Insert_range_unchecked(_RANGES _Ubegin(_Range), _RANGES _Uend(_Range));
     }
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 
     void insert(initializer_list<value_type> _Ilist) {
         _Insert_range_unchecked(_Ilist.begin(), _Ilist.end());
diff --git a/stl/inc/yvals_core.h b/stl/inc/yvals_core.h
index abe49bc01a..213263eced 100644
--- a/stl/inc/yvals_core.h
+++ b/stl/inc/yvals_core.h
@@ -1396,7 +1396,7 @@ _EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpect
 #define __cpp_lib_concepts 202002L
 #endif // !defined(__EDG__) || defined(__INTELLISENSE__)
 
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #define __cpp_lib_algorithm_iterator_requirements 202207L
 #endif // __cpp_lib_concepts
 
@@ -1428,7 +1428,7 @@ _EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpect
 #define __cpp_lib_endian                  201907L
 #define __cpp_lib_erase_if                202002L
 
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #define __cpp_lib_format 202110L
 #endif // __cpp_lib_concepts
 
@@ -1457,7 +1457,7 @@ _EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpect
 #define __cpp_lib_list_remove_return_type 201806L
 #define __cpp_lib_math_constants          201907L
 
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #define __cpp_lib_move_iterator_concept 202207L
 #endif // __cpp_lib_concepts
 
@@ -1476,7 +1476,7 @@ _EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpect
 #define __cpp_lib_starts_ends_with 201711L
 #define __cpp_lib_syncbuf          201803L
 
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #define __cpp_lib_three_way_comparison 201907L
 #endif // __cpp_lib_concepts
 
@@ -1541,7 +1541,7 @@ _EMIT_STL_ERROR(STL1004, "C++98 unexpected() is incompatible with C++23 unexpect
 #define __cpp_lib_array_constexpr 201803L // P0858R0 Constexpr Iterator Requirements
 #endif // _HAS_CXX17
 
-#if _HAS_CXX20 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #define __cpp_lib_chrono 201907L // P1466R3 Miscellaneous Minor Fixes For <chrono>
 #elif _HAS_CXX17
 #define __cpp_lib_chrono 201611L // P0505R0 constexpr For <chrono> (Again)
diff --git a/tests/std/tests/GH_000545_include_compare/test_ranges.cpp b/tests/std/tests/GH_000545_include_compare/test_ranges.cpp
index bd71d183ce..fc4c9fd515 100644
--- a/tests/std/tests/GH_000545_include_compare/test_ranges.cpp
+++ b/tests/std/tests/GH_000545_include_compare/test_ranges.cpp
@@ -2,7 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 #include <version> // TRANSITION, GH-395
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 
 #include <ranges>
 
@@ -10,6 +10,6 @@
 
 static_assert(std::is_eq(std::partial_ordering::equivalent));
 
-#endif // TRANSITION, GH-395
+#endif // __cpp_lib_concepts
 
 void test_ranges() {}
diff --git a/tests/std/tests/GH_002989_nothrow_unwrappable/test.cpp b/tests/std/tests/GH_002989_nothrow_unwrappable/test.cpp
index a92bc561ce..22928a565e 100644
--- a/tests/std/tests/GH_002989_nothrow_unwrappable/test.cpp
+++ b/tests/std/tests/GH_002989_nothrow_unwrappable/test.cpp
@@ -49,7 +49,7 @@ void do_full_test() {
     do_single_test<reverse_iterator<It>, CopyUnwrapNothrow>();
     do_single_test<move_iterator<It>, CopyUnwrapNothrow>();
 
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
     using R = ranges::subrange<It, It>;
 
     // TRANSITION, GH-2997
diff --git a/tests/std/tests/P0355R7_calendars_and_time_zones_clocks/test.cpp b/tests/std/tests/P0355R7_calendars_and_time_zones_clocks/test.cpp
index f1db6f7286..ab019ad78e 100644
--- a/tests/std/tests/P0355R7_calendars_and_time_zones_clocks/test.cpp
+++ b/tests/std/tests/P0355R7_calendars_and_time_zones_clocks/test.cpp
@@ -154,7 +154,7 @@ constexpr bool test_leap_second() {
     static_assert(noexcept(equal >= leap));
     static_assert(noexcept(leap >= equal));
 
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
     static_assert(is_eq(leap <=> equal));
     static_assert(is_lt(leap <=> larger));
     static_assert(is_gt(leap <=> smaller));
diff --git a/tests/std/tests/P0433R2_deduction_guides/test.cpp b/tests/std/tests/P0433R2_deduction_guides/test.cpp
index 97f9b2b4fd..58785806c5 100644
--- a/tests/std/tests/P0433R2_deduction_guides/test.cpp
+++ b/tests/std/tests/P0433R2_deduction_guides/test.cpp
@@ -507,13 +507,13 @@ void test_basic_string() {
     static_assert(is_same_v<decltype(str17), basic_string<wchar_t, char_traits<wchar_t>, MyAlloc<wchar_t>>>);
     static_assert(is_same_v<decltype(str18), basic_string<wchar_t, char_traits<wchar_t>, MyAlloc<wchar_t>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     basic_string str19(from_range, first);
     basic_string str20(from_range, first, myal);
 
     static_assert(is_same_v<decltype(str19), wstring>);
     static_assert(is_same_v<decltype(str20), basic_string<wchar_t, char_traits<wchar_t>, MyAlloc<wchar_t>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 void test_basic_string_view() {
@@ -573,13 +573,13 @@ void test_sequence_container() {
     static_assert(is_same_v<decltype(c6), Sequence<long, MyAlloc<long>>>);
     static_assert(is_same_v<decltype(c7), Sequence<long, MyAlloc<long>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     Sequence c8(from_range, first);
     Sequence c9(from_range, first, myal);
 
     static_assert(is_same_v<decltype(c8), Sequence<long>>);
     static_assert(is_same_v<decltype(c9), Sequence<long, MyAlloc<long>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 void test_vector_bool() {
@@ -604,13 +604,13 @@ void test_vector_bool() {
     static_assert(is_same_v<decltype(vb6), vector<bool, MyAlloc<bool>>>);
     static_assert(is_same_v<decltype(vb7), vector<bool, MyAlloc<bool>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     vector vb8(from_range, first);
     vector vb9(from_range, first, myal);
 
     static_assert(is_same_v<decltype(vb8), vector<bool>>);
     static_assert(is_same_v<decltype(vb9), vector<bool, MyAlloc<bool>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 template <template <typename K, typename V, typename C = less<K>, typename A = allocator<pair<const K, V>>> typename M>
@@ -647,7 +647,7 @@ void test_map_or_multimap() {
     static_assert(is_same_v<decltype(m12), M<long, char, MyGreater, MyAlloc<CPurr>>>);
     static_assert(is_same_v<decltype(m13), M<long, char, less<long>, MyAlloc<CPurr>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     M m14(from_range, first);
     M m15(from_range, first, gt);
     M m16(from_range, first, gt, myal);
@@ -657,7 +657,7 @@ void test_map_or_multimap() {
     static_assert(is_same_v<decltype(m15), M<long, char, MyGreater>>);
     static_assert(is_same_v<decltype(m16), M<long, char, MyGreater, MyAlloc<CPurr>>>);
     static_assert(is_same_v<decltype(m17), M<long, char, less<long>, MyAlloc<CPurr>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 template <template <typename K, typename C = less<K>, typename A = allocator<K>> typename S>
@@ -688,7 +688,7 @@ void test_set_or_multiset() {
     static_assert(is_same_v<decltype(s8), S<long, less<long>, MyAlloc<long>>>);
     static_assert(is_same_v<decltype(s9), S<long, less<long>, MyAlloc<long>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     S s10(from_range, first);
     S s11(from_range, first, gt);
     S s12(from_range, first, gt, myal);
@@ -698,7 +698,7 @@ void test_set_or_multiset() {
     static_assert(is_same_v<decltype(s11), S<long, MyGreater>>);
     static_assert(is_same_v<decltype(s12), S<long, MyGreater, MyAlloc<long>>>);
     static_assert(is_same_v<decltype(s13), S<long, less<long>, MyAlloc<long>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 template <template <typename K, typename V, typename H = hash<K>, typename P = equal_to<K>,
@@ -752,7 +752,7 @@ void test_unordered_map_or_unordered_multimap() {
     static_assert(is_same_v<decltype(um24), UM<long, char, hash<long>, equal_to<long>, MyAlloc<CPurr>>>);
     static_assert(is_same_v<decltype(um25), UM<long, char, MyHash, equal_to<long>, MyAlloc<CPurr>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     UM um26(from_range, first);
     UM um27(from_range, first, 7);
     UM um28(from_range, first, 7, hf);
@@ -770,7 +770,7 @@ void test_unordered_map_or_unordered_multimap() {
     static_assert(is_same_v<decltype(um31), UM<long, char, hash<long>, equal_to<long>, MyAlloc<CPurr>>>);
     static_assert(is_same_v<decltype(um32), UM<long, char, hash<long>, equal_to<long>, MyAlloc<CPurr>>>);
     static_assert(is_same_v<decltype(um33), UM<long, char, MyHash, equal_to<long>, MyAlloc<CPurr>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 template <template <typename K, typename H = hash<K>, typename P = equal_to<K>, typename A = allocator<K>> typename US>
@@ -814,7 +814,7 @@ void test_unordered_set_or_unordered_multiset() {
     static_assert(is_same_v<decltype(us14), US<long, MyHash, equal_to<long>, MyAlloc<long>>>);
     static_assert(is_same_v<decltype(us15), US<long, MyHash, MyEqual, MyAlloc<long>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     US us16(from_range, first);
     US us17(from_range, first, 7);
     US us18(from_range, first, 7, hf);
@@ -830,7 +830,7 @@ void test_unordered_set_or_unordered_multiset() {
     static_assert(is_same_v<decltype(us20), US<long, MyHash, MyEqual, MyAlloc<long>>>);
     static_assert(is_same_v<decltype(us21), US<long, hash<long>, equal_to<long>, MyAlloc<long>>>);
     static_assert(is_same_v<decltype(us22), US<long, MyHash, equal_to<long>, MyAlloc<long>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 void test_queue_and_stack() {
@@ -855,13 +855,13 @@ void test_queue_and_stack() {
     static_assert(is_same_v<decltype(q4), queue<long>>);
     static_assert(is_same_v<decltype(q5), queue<long, deque<long, MyAlloc<long>>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
     queue q6(from_range, first);
     queue q7(from_range, first, myal);
 
     static_assert(is_same_v<decltype(q6), queue<long>>);
     static_assert(is_same_v<decltype(q7), queue<long, deque<long, MyAlloc<long>>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 
     stack s1(lst);
@@ -879,13 +879,13 @@ void test_queue_and_stack() {
     static_assert(is_same_v<decltype(s4), stack<long>>);
     static_assert(is_same_v<decltype(s5), stack<long, deque<long, MyAlloc<long>>>>);
 
-#ifdef __cpp_lib_containers_ranges
+#ifdef __cpp_lib_concepts
     stack s6(from_range, first);
     stack s7(from_range, first, myal);
 
     static_assert(is_same_v<decltype(s6), stack<long>>);
     static_assert(is_same_v<decltype(s7), stack<long, deque<long, MyAlloc<long>>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // __cpp_lib_concepts
 #endif // _HAS_CXX23
 }
 
@@ -916,7 +916,7 @@ void test_priority_queue() {
     static_assert(is_same_v<decltype(pq8), priority_queue<long, deque<long, MyAlloc<long>>, MyGreater>>);
     static_assert(is_same_v<decltype(pq9), priority_queue<long, deque<long, MyAlloc<long>>, MyGreater>>);
 
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
     priority_queue pq10(from_range, first);
     priority_queue pq11(from_range, first, gt);
     priority_queue pq12(from_range, first, gt, myal);
@@ -926,7 +926,7 @@ void test_priority_queue() {
     static_assert(is_same_v<decltype(pq11), priority_queue<long, vector<long>, MyGreater>>);
     static_assert(is_same_v<decltype(pq12), priority_queue<long, vector<long, MyAlloc<long>>, MyGreater>>);
     static_assert(is_same_v<decltype(pq13), priority_queue<long, vector<long, MyAlloc<long>>>>);
-#endif // __cpp_lib_containers_ranges
+#endif // _HAS_CXX23 && defined(__cpp_lib_concepts)
 }
 
 void test_iterator_adaptors() {
diff --git a/tests/std/tests/P0980R1_constexpr_strings/test.cpp b/tests/std/tests/P0980R1_constexpr_strings/test.cpp
index 20515dc086..8a2b6ef98a 100644
--- a/tests/std/tests/P0980R1_constexpr_strings/test.cpp
+++ b/tests/std/tests/P0980R1_constexpr_strings/test.cpp
@@ -165,9 +165,10 @@ struct string_view_convertible {
     }
 };
 
+// TRANSITION, GH-395 (equalRanges should be replaced by direct calls to ranges::equal)
 template <class Range1, class Range2>
 constexpr bool equalRanges(const Range1& range1, const Range2& range2) noexcept {
-#ifdef __cpp_lib_concepts // TRANSITION, GH-395 (equalRanges should be replaced by direct calls to ranges::equal)
+#ifdef __cpp_lib_concepts
     return ranges::equal(range1, range2);
 #else // ^^^ __cpp_lib_concepts ^^^ / vvv !__cpp_lib_concepts vvv
     return equal(begin(range1), end(range1), begin(range2), end(range2));
diff --git a/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp b/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp
index 393d37fa91..1d9c437e3d 100644
--- a/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp
+++ b/tests/std/tests/VSO_0157762_feature_test_macros/test.compile.pass.cpp
@@ -30,7 +30,7 @@ STATIC_ASSERT(__cpp_lib_adaptor_iterator_pair_constructor == 202106L);
 STATIC_ASSERT(__cpp_lib_addressof_constexpr == 201603L);
 #endif
 
-#if _HAS_CXX20 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #ifndef __cpp_lib_algorithm_iterator_requirements
 #error __cpp_lib_algorithm_iterator_requirements is not defined
 #elif __cpp_lib_algorithm_iterator_requirements != 202207L
@@ -408,7 +408,7 @@ STATIC_ASSERT(__cpp_lib_char8_t == 201907L);
 
 #ifndef __cpp_lib_chrono
 #error __cpp_lib_chrono is not defined
-#elif _HAS_CXX20 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
+#elif defined(__cpp_lib_concepts)
 #if __cpp_lib_chrono != 201907L
 #error __cpp_lib_chrono is not 201907L
 #else
@@ -699,7 +699,7 @@ STATIC_ASSERT(__cpp_lib_constexpr_vector == 201907L);
 STATIC_ASSERT(__cpp_lib_containers_ranges == 202202L);
 #endif
 #else
-#ifdef __cpp_lib_containers_ranges
+#if _HAS_CXX23 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
 #error __cpp_lib_containers_ranges is defined
 #endif
 #endif
@@ -842,7 +842,7 @@ STATIC_ASSERT(__cpp_lib_filesystem == 201703L);
 #endif
 #endif
 
-#if _HAS_CXX20 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #ifndef __cpp_lib_format
 #error __cpp_lib_format is not defined
 #elif __cpp_lib_format != 202110L
@@ -1316,7 +1316,7 @@ STATIC_ASSERT(__cpp_lib_memory_resource == 201603L);
 #endif
 #endif
 
-#if _HAS_CXX20 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #ifndef __cpp_lib_move_iterator_concept
 #error __cpp_lib_move_iterator_concept is not defined
 #elif __cpp_lib_move_iterator_concept != 202207L
@@ -1476,7 +1476,7 @@ STATIC_ASSERT(__cpp_lib_quoted_string_io == 201304L);
 #else
 STATIC_ASSERT(__cpp_lib_ranges == 202207L);
 #endif
-#elif _HAS_CXX20 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
+#elif defined(__cpp_lib_concepts)
 #ifndef __cpp_lib_ranges
 #error __cpp_lib_ranges is not defined
 #elif __cpp_lib_ranges != 202110L
@@ -1970,7 +1970,7 @@ STATIC_ASSERT(__cpp_lib_syncbuf == 201803L);
 #endif
 #endif
 
-#if _HAS_CXX20 && defined(__cpp_lib_concepts) // TRANSITION, GH-395
+#ifdef __cpp_lib_concepts
 #ifndef __cpp_lib_three_way_comparison
 #error __cpp_lib_three_way_comparison is not defined
 #elif __cpp_lib_three_way_comparison != 201907L