diff --git a/libcxx/include/__algorithm/in_in_out_result.h b/libcxx/include/__algorithm/in_in_out_result.h
--- a/libcxx/include/__algorithm/in_in_out_result.h
+++ b/libcxx/include/__algorithm/in_in_out_result.h
@@ -16,7 +16,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifndef _LIBCPP_HAS_NO_CONCEPTS
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
 template <class _I1, class _I2, class _O1>
@@ -41,8 +41,8 @@
 };
 } // namespace ranges
 
-#endif // _LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
-#endif // _LIBCPP___ALGORITHM_IN_IN_RESULT_H
+#endif // _LIBCPP___ALGORITHM_IN_IN_OUT_RESULT_H
diff --git a/libcxx/include/__algorithm/in_in_result.h b/libcxx/include/__algorithm/in_in_result.h
--- a/libcxx/include/__algorithm/in_in_result.h
+++ b/libcxx/include/__algorithm/in_in_result.h
@@ -16,7 +16,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifndef _LIBCPP_HAS_NO_CONCEPTS
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
 template <class _I1, class _I2>
@@ -38,7 +38,7 @@
 };
 } // namespace ranges
 
-#endif // _LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__algorithm/in_out_result.h b/libcxx/include/__algorithm/in_out_result.h
--- a/libcxx/include/__algorithm/in_out_result.h
+++ b/libcxx/include/__algorithm/in_out_result.h
@@ -20,7 +20,8 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
 namespace ranges {
 
 template<class _InputIterator, class _OutputIterator>
@@ -45,7 +46,8 @@
 };
 
 } // namespace ranges
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__concepts/swappable.h b/libcxx/include/__concepts/swappable.h
--- a/libcxx/include/__concepts/swappable.h
+++ b/libcxx/include/__concepts/swappable.h
@@ -29,6 +29,8 @@
 
 // [concept.swappable]
 
+#if !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
 namespace ranges {
 namespace __swap {
 
@@ -109,6 +111,25 @@
     ranges::swap(_VSTD::forward<_Up>(__u), _VSTD::forward<_Tp>(__t));
   };
 
+#else
+
+// If _LIBCPP_HAS_NO_INCOMPLETE_RANGES is true, substitute a fake std::swappable concept.
+
+template<class _Tp>
+concept swappable = requires(_Tp& __a, _Tp& __b) { swap(__a, __b); };
+
+template<class _Tp, class _Up>
+concept swappable_with =
+  common_reference_with<_Tp, _Up> &&
+  requires(_Tp&& __t, _Up&& __u) {
+    swap(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Tp>(__t));
+    swap(_VSTD::forward<_Up>(__u), _VSTD::forward<_Up>(__u));
+    swap(_VSTD::forward<_Tp>(__t), _VSTD::forward<_Up>(__u));
+    swap(_VSTD::forward<_Up>(__u), _VSTD::forward<_Tp>(__t));
+  };
+
+#endif // defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
 #endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
 
 _LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/include/__filesystem/directory_iterator.h b/libcxx/include/__filesystem/directory_iterator.h
--- a/libcxx/include/__filesystem/directory_iterator.h
+++ b/libcxx/include/__filesystem/directory_iterator.h
@@ -133,7 +133,7 @@
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 template <>
 _LIBCPP_AVAILABILITY_FILESYSTEM
@@ -143,7 +143,7 @@
 _LIBCPP_AVAILABILITY_FILESYSTEM
 inline constexpr bool _VSTD::ranges::enable_view<_VSTD_FS::directory_iterator> = true;
 
-#endif
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 #endif // _LIBCPP_CXX03_LANG
 
diff --git a/libcxx/include/__filesystem/recursive_directory_iterator.h b/libcxx/include/__filesystem/recursive_directory_iterator.h
--- a/libcxx/include/__filesystem/recursive_directory_iterator.h
+++ b/libcxx/include/__filesystem/recursive_directory_iterator.h
@@ -164,7 +164,7 @@
 
 _LIBCPP_END_NAMESPACE_FILESYSTEM
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 template <>
 _LIBCPP_AVAILABILITY_FILESYSTEM
@@ -174,7 +174,7 @@
 _LIBCPP_AVAILABILITY_FILESYSTEM
 inline constexpr bool _VSTD::ranges::enable_view<_VSTD_FS::recursive_directory_iterator> = true;
 
-#endif
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 #endif // _LIBCPP_CXX03_LANG
 
diff --git a/libcxx/include/__functional/ranges_operations.h b/libcxx/include/__functional/ranges_operations.h
--- a/libcxx/include/__functional/ranges_operations.h
+++ b/libcxx/include/__functional/ranges_operations.h
@@ -20,7 +20,8 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
 namespace ranges {
 
 struct equal_to {
@@ -90,7 +91,7 @@
 };
 
 } // namespace ranges
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/advance.h b/libcxx/include/__iterator/advance.h
--- a/libcxx/include/__iterator/advance.h
+++ b/libcxx/include/__iterator/advance.h
@@ -64,7 +64,7 @@
   _VSTD::__advance(__i, __n, typename iterator_traits<_InputIter>::iterator_category());
 }
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [range.iter.op.advance]
 
@@ -192,7 +192,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/common_iterator.h b/libcxx/include/__iterator/common_iterator.h
--- a/libcxx/include/__iterator/common_iterator.h
+++ b/libcxx/include/__iterator/common_iterator.h
@@ -27,7 +27,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 template<class _Iter>
 concept __can_use_postfix_proxy =
@@ -276,7 +276,7 @@
   using reference = iter_reference_t<_Iter>;
 };
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/concepts.h b/libcxx/include/__iterator/concepts.h
--- a/libcxx/include/__iterator/concepts.h
+++ b/libcxx/include/__iterator/concepts.h
@@ -26,7 +26,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [iterator.concept.readable]
 template<class _In>
@@ -257,7 +257,7 @@
 // Note: indirectly_swappable is located in iter_swap.h to prevent a dependency cycle
 // (both iter_swap and indirectly_swappable require indirectly_readable).
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/counted_iterator.h b/libcxx/include/__iterator/counted_iterator.h
--- a/libcxx/include/__iterator/counted_iterator.h
+++ b/libcxx/include/__iterator/counted_iterator.h
@@ -30,7 +30,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 template<class>
 struct __counted_iterator_concept {};
@@ -296,7 +296,7 @@
                                 add_pointer_t<iter_reference_t<_Iter>>, void>;
 };
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/default_sentinel.h b/libcxx/include/__iterator/default_sentinel.h
--- a/libcxx/include/__iterator/default_sentinel.h
+++ b/libcxx/include/__iterator/default_sentinel.h
@@ -18,12 +18,12 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 struct default_sentinel_t { };
 inline constexpr default_sentinel_t default_sentinel{};
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/distance.h b/libcxx/include/__iterator/distance.h
--- a/libcxx/include/__iterator/distance.h
+++ b/libcxx/include/__iterator/distance.h
@@ -52,7 +52,7 @@
     return _VSTD::__distance(__first, __last, typename iterator_traits<_InputIter>::iterator_category());
 }
 
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [range.iter.op.distance]
 
@@ -100,7 +100,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/indirectly_comparable.h b/libcxx/include/__iterator/indirectly_comparable.h
--- a/libcxx/include/__iterator/indirectly_comparable.h
+++ b/libcxx/include/__iterator/indirectly_comparable.h
@@ -17,13 +17,13 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#ifndef _LIBCPP_HAS_NO_CONCEPTS
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 template <class _I1, class _I2, class _Rp, class _P1 = identity, class _P2 = identity>
 concept indirectly_comparable =
   indirect_binary_predicate<_Rp, projected<_I1, _P1>, projected<_I2, _P2>>;
 
-#endif // _LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/insert_iterator.h b/libcxx/include/__iterator/insert_iterator.h
--- a/libcxx/include/__iterator/insert_iterator.h
+++ b/libcxx/include/__iterator/insert_iterator.h
@@ -24,7 +24,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template <class _Container>
 using __insert_iterator_iter_t = ranges::iterator_t<_Container>;
 #else
diff --git a/libcxx/include/__iterator/iter_move.h b/libcxx/include/__iterator/iter_move.h
--- a/libcxx/include/__iterator/iter_move.h
+++ b/libcxx/include/__iterator/iter_move.h
@@ -23,7 +23,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [iterator.cust.move]
 
@@ -86,7 +86,7 @@
   requires requires(_Tp& __t) { { ranges::iter_move(__t) } -> __referenceable; }
 using iter_rvalue_reference_t = decltype(ranges::iter_move(declval<_Tp&>()));
 
-#endif // !_LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/iter_swap.h b/libcxx/include/__iterator/iter_swap.h
--- a/libcxx/include/__iterator/iter_swap.h
+++ b/libcxx/include/__iterator/iter_swap.h
@@ -26,7 +26,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [iter.cust.swap]
 
@@ -100,7 +100,7 @@
     ranges::iter_swap(__i2, __i1);
   };
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/next.h b/libcxx/include/__iterator/next.h
--- a/libcxx/include/__iterator/next.h
+++ b/libcxx/include/__iterator/next.h
@@ -35,7 +35,7 @@
   return __x;
 }
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [range.iter.op.next]
 
@@ -79,7 +79,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/prev.h b/libcxx/include/__iterator/prev.h
--- a/libcxx/include/__iterator/prev.h
+++ b/libcxx/include/__iterator/prev.h
@@ -34,7 +34,7 @@
   return __x;
 }
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [range.iter.op.prev]
 
@@ -71,7 +71,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/projected.h b/libcxx/include/__iterator/projected.h
--- a/libcxx/include/__iterator/projected.h
+++ b/libcxx/include/__iterator/projected.h
@@ -20,7 +20,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 template<indirectly_readable _It, indirectly_regular_unary_invocable<_It> _Proj>
 struct projected {
@@ -33,7 +33,7 @@
   using difference_type = iter_difference_t<_It>;
 };
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__iterator/unreachable_sentinel.h b/libcxx/include/__iterator/unreachable_sentinel.h
--- a/libcxx/include/__iterator/unreachable_sentinel.h
+++ b/libcxx/include/__iterator/unreachable_sentinel.h
@@ -19,7 +19,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 struct unreachable_sentinel_t {
   template<weakly_incrementable _Iter>
@@ -31,7 +31,7 @@
 
 inline constexpr unreachable_sentinel_t unreachable_sentinel{};
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__memory/concepts.h b/libcxx/include/__memory/concepts.h
--- a/libcxx/include/__memory/concepts.h
+++ b/libcxx/include/__memory/concepts.h
@@ -25,7 +25,8 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
 namespace ranges {
 
 // [special.mem.concepts]
@@ -59,7 +60,8 @@
     __nothrow_forward_iterator<iterator_t<_Rp>>;
 
 } // namespace ranges
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__memory/ranges_construct_at.h b/libcxx/include/__memory/ranges_construct_at.h
--- a/libcxx/include/__memory/ranges_construct_at.h
+++ b/libcxx/include/__memory/ranges_construct_at.h
@@ -29,7 +29,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 namespace ranges {
 
 // construct_at
@@ -117,7 +117,7 @@
 
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__memory/ranges_uninitialized_algorithms.h b/libcxx/include/__memory/ranges_uninitialized_algorithms.h
--- a/libcxx/include/__memory/ranges_uninitialized_algorithms.h
+++ b/libcxx/include/__memory/ranges_uninitialized_algorithms.h
@@ -32,7 +32,8 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
 namespace ranges {
 
 // uninitialized_default_construct
@@ -309,7 +310,8 @@
 } // namespace __cpo
 
 } // namespace ranges
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/access.h b/libcxx/include/__ranges/access.h
--- a/libcxx/include/__ranges/access.h
+++ b/libcxx/include/__ranges/access.h
@@ -25,7 +25,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template <class _Tp>
@@ -213,7 +213,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/all.h b/libcxx/include/__ranges/all.h
--- a/libcxx/include/__ranges/all.h
+++ b/libcxx/include/__ranges/all.h
@@ -28,7 +28,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges::views {
 
@@ -75,7 +75,7 @@
 
 } // namespace ranges::views
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/common_view.h b/libcxx/include/__ranges/common_view.h
--- a/libcxx/include/__ranges/common_view.h
+++ b/libcxx/include/__ranges/common_view.h
@@ -30,7 +30,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
 
@@ -128,7 +128,7 @@
 } // namespace views
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/concepts.h b/libcxx/include/__ranges/concepts.h
--- a/libcxx/include/__ranges/concepts.h
+++ b/libcxx/include/__ranges/concepts.h
@@ -32,7 +32,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   // [range.range]
@@ -133,7 +133,7 @@
 
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/copyable_box.h b/libcxx/include/__ranges/copyable_box.h
--- a/libcxx/include/__ranges/copyable_box.h
+++ b/libcxx/include/__ranges/copyable_box.h
@@ -24,7 +24,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // __copyable_box allows turning a type that is copy-constructible (but maybe not copy-assignable) into
 // a type that is both copy-constructible and copy-assignable. It does that by introducing an empty state
@@ -171,7 +171,7 @@
   };
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/counted.h b/libcxx/include/__ranges/counted.h
--- a/libcxx/include/__ranges/counted.h
+++ b/libcxx/include/__ranges/counted.h
@@ -29,7 +29,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges::views {
 
@@ -74,7 +74,7 @@
 
 } // namespace ranges::views
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/dangling.h b/libcxx/include/__ranges/dangling.h
--- a/libcxx/include/__ranges/dangling.h
+++ b/libcxx/include/__ranges/dangling.h
@@ -21,7 +21,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
 struct dangling {
@@ -35,7 +35,7 @@
 // borrowed_subrange_t defined in <__ranges/subrange.h>
 } // namespace ranges
 
-#endif // !_LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/data.h b/libcxx/include/__ranges/data.h
--- a/libcxx/include/__ranges/data.h
+++ b/libcxx/include/__ranges/data.h
@@ -24,7 +24,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [range.prim.data]
 
@@ -99,7 +99,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/drop_view.h b/libcxx/include/__ranges/drop_view.h
--- a/libcxx/include/__ranges/drop_view.h
+++ b/libcxx/include/__ranges/drop_view.h
@@ -31,7 +31,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<view _View>
@@ -120,7 +120,7 @@
   inline constexpr bool enable_borrowed_range<drop_view<_Tp>> = enable_borrowed_range<_Tp>;
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/empty.h b/libcxx/include/__ranges/empty.h
--- a/libcxx/include/__ranges/empty.h
+++ b/libcxx/include/__ranges/empty.h
@@ -22,7 +22,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [range.prim.empty]
 
@@ -75,7 +75,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/empty_view.h b/libcxx/include/__ranges/empty_view.h
--- a/libcxx/include/__ranges/empty_view.h
+++ b/libcxx/include/__ranges/empty_view.h
@@ -20,7 +20,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<class _Tp>
@@ -38,7 +38,7 @@
   inline constexpr bool enable_borrowed_range<empty_view<_Tp>> = true;
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/enable_borrowed_range.h b/libcxx/include/__ranges/enable_borrowed_range.h
--- a/libcxx/include/__ranges/enable_borrowed_range.h
+++ b/libcxx/include/__ranges/enable_borrowed_range.h
@@ -22,10 +22,9 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
-namespace ranges
-{
+namespace ranges {
 
 // [range.range], ranges
 
@@ -34,7 +33,7 @@
 
 } // namespace ranges
 
-#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/enable_view.h b/libcxx/include/__ranges/enable_view.h
--- a/libcxx/include/__ranges/enable_view.h
+++ b/libcxx/include/__ranges/enable_view.h
@@ -20,7 +20,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
 
@@ -40,7 +40,7 @@
 
 } // namespace ranges
 
-#endif // !_LIBCPP_HAS_NO_CONCEPTS
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/iota_view.h b/libcxx/include/__ranges/iota_view.h
--- a/libcxx/include/__ranges/iota_view.h
+++ b/libcxx/include/__ranges/iota_view.h
@@ -39,7 +39,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<class _Int>
@@ -401,7 +401,7 @@
 } // namespace views
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/join_view.h b/libcxx/include/__ranges/join_view.h
--- a/libcxx/include/__ranges/join_view.h
+++ b/libcxx/include/__ranges/join_view.h
@@ -30,7 +30,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<class>
@@ -343,7 +343,7 @@
 
 #undef _CONSTEXPR_TERNARY
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/non_propagating_cache.h b/libcxx/include/__ranges/non_propagating_cache.h
--- a/libcxx/include/__ranges/non_propagating_cache.h
+++ b/libcxx/include/__ranges/non_propagating_cache.h
@@ -24,7 +24,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   // __non_propagating_cache is a helper type that allows storing an optional value in it,
@@ -107,7 +107,7 @@
   struct __empty_cache { };
 } // namespace ranges
 
-#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/owning_view.h b/libcxx/include/__ranges/owning_view.h
--- a/libcxx/include/__ranges/owning_view.h
+++ b/libcxx/include/__ranges/owning_view.h
@@ -28,7 +28,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<range _Rp>
@@ -74,7 +74,7 @@
 
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/range_adaptor.h b/libcxx/include/__ranges/range_adaptor.h
--- a/libcxx/include/__ranges/range_adaptor.h
+++ b/libcxx/include/__ranges/range_adaptor.h
@@ -25,7 +25,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // CRTP base that one can derive from in order to be considered a range adaptor closure
 // by the library. When deriving from this class, a pipe operator will be provided to
@@ -66,7 +66,7 @@
     { return __range_adaptor_closure_t(_VSTD::__compose(_VSTD::forward<_OtherClosure>(__c2), _VSTD::forward<_Closure>(__c1))); }
 };
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/ref_view.h b/libcxx/include/__ranges/ref_view.h
--- a/libcxx/include/__ranges/ref_view.h
+++ b/libcxx/include/__ranges/ref_view.h
@@ -31,7 +31,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<range _Range>
@@ -79,7 +79,7 @@
   inline constexpr bool enable_borrowed_range<ref_view<_Tp>> = true;
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/reverse_view.h b/libcxx/include/__ranges/reverse_view.h
--- a/libcxx/include/__ranges/reverse_view.h
+++ b/libcxx/include/__ranges/reverse_view.h
@@ -33,7 +33,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<view _View>
@@ -183,7 +183,7 @@
   } // namespace views
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/single_view.h b/libcxx/include/__ranges/single_view.h
--- a/libcxx/include/__ranges/single_view.h
+++ b/libcxx/include/__ranges/single_view.h
@@ -24,7 +24,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<copy_constructible _Tp>
@@ -74,7 +74,7 @@
   single_view(_Tp) -> single_view<_Tp>;
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/size.h b/libcxx/include/__ranges/size.h
--- a/libcxx/include/__ranges/size.h
+++ b/libcxx/include/__ranges/size.h
@@ -24,7 +24,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<class>
@@ -128,7 +128,7 @@
 } // namespace __cpo
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/subrange.h b/libcxx/include/__ranges/subrange.h
--- a/libcxx/include/__ranges/subrange.h
+++ b/libcxx/include/__ranges/subrange.h
@@ -36,7 +36,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<class _From, class _To>
@@ -282,7 +282,7 @@
   using type = _Sp;
 };
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/take_view.h b/libcxx/include/__ranges/take_view.h
--- a/libcxx/include/__ranges/take_view.h
+++ b/libcxx/include/__ranges/take_view.h
@@ -34,7 +34,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
   template<view _View>
@@ -176,7 +176,7 @@
   inline constexpr bool enable_borrowed_range<take_view<_Tp>> = enable_borrowed_range<_Tp>;
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/transform_view.h b/libcxx/include/__ranges/transform_view.h
--- a/libcxx/include/__ranges/transform_view.h
+++ b/libcxx/include/__ranges/transform_view.h
@@ -41,7 +41,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
 
@@ -433,7 +433,7 @@
 
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/__ranges/view_interface.h b/libcxx/include/__ranges/view_interface.h
--- a/libcxx/include/__ranges/view_interface.h
+++ b/libcxx/include/__ranges/view_interface.h
@@ -27,7 +27,7 @@
 
 _LIBCPP_BEGIN_NAMESPACE_STD
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 namespace ranges {
 
@@ -188,7 +188,7 @@
 
 } // namespace ranges
 
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 _LIBCPP_END_NAMESPACE_STD
 
diff --git a/libcxx/include/span b/libcxx/include/span
--- a/libcxx/include/span
+++ b/libcxx/include/span
@@ -170,7 +170,7 @@
 template <class _Tp, size_t _Sz>
 struct __is_std_span<span<_Tp, _Sz>> : true_type {};
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template <class _Range, class _ElementType>
 concept __span_compatible_range =
   ranges::contiguous_range<_Range> &&
@@ -210,7 +210,7 @@
     constexpr span           (const span&) noexcept = default;
     constexpr span& operator=(const span&) noexcept = default;
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <class _It,
               enable_if_t<contiguous_iterator<_It> &&
                               is_convertible_v<remove_reference_t<iter_reference_t<_It>>(*)[], element_type (*)[]>,
@@ -234,7 +234,7 @@
       _LIBCPP_ASSERT(__last - __first == _Extent,
                      "invalid range in span's constructor (iterator, sentinel): last - first != extent");
     }
-#endif
+#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
     _LIBCPP_INLINE_VISIBILITY constexpr span(type_identity_t<element_type> (&__arr)[_Extent]) noexcept : __data{__arr} {}
 
@@ -248,13 +248,13 @@
     _LIBCPP_INLINE_VISIBILITY
     constexpr span(const array<_OtherElementType, _Extent>& __arr) noexcept : __data{__arr.data()} {}
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <__span_compatible_range<element_type> _Range>
     _LIBCPP_INLINE_VISIBILITY
     constexpr explicit span(_Range&& __r) : __data{ranges::data(__r)} {
       _LIBCPP_ASSERT(ranges::size(__r) == _Extent, "size mismatch in span's constructor (range)");
     }
-#endif
+#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
     template <class _OtherElementType>
     _LIBCPP_INLINE_VISIBILITY
@@ -401,7 +401,7 @@
     constexpr span           (const span&) noexcept = default;
     constexpr span& operator=(const span&) noexcept = default;
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <class _It,
               enable_if_t<contiguous_iterator<_It> &&
                               is_convertible_v<remove_reference_t<iter_reference_t<_It> > (*)[], element_type (*)[]>,
@@ -434,11 +434,11 @@
     _LIBCPP_INLINE_VISIBILITY
     constexpr span(const array<_OtherElementType, _Sz>& __arr) noexcept : __data{__arr.data()}, __size{_Sz} {}
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <__span_compatible_range<element_type> _Range>
     _LIBCPP_INLINE_VISIBILITY
     constexpr span(_Range&& __r) : __data(ranges::data(__r)), __size{ranges::size(__r)} {}
-#  endif
+#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
     template <class _OtherElementType, size_t _OtherExtent>
     _LIBCPP_INLINE_VISIBILITY
@@ -543,13 +543,13 @@
     size_type __size;
 };
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template <class _Tp, size_t _Extent>
 inline constexpr bool ranges::enable_borrowed_range<span<_Tp, _Extent> > = true;
 
 template <class _ElementType, size_t _Extent>
 inline constexpr bool ranges::enable_view<span<_ElementType, _Extent>> = true;
-#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 //  as_bytes & as_writable_bytes
 template <class _Tp, size_t _Extent>
@@ -564,8 +564,7 @@
 -> enable_if_t<!is_const_v<_Tp>, decltype(__s.__as_writable_bytes())>
 { return __s.__as_writable_bytes(); }
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
-//  Deduction guides
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template<contiguous_iterator _It, class _EndOrSize>
     span(_It, _EndOrSize) -> span<remove_reference_t<iter_reference_t<_It>>>;
 #endif
@@ -579,7 +578,7 @@
 template<class _Tp, size_t _Sz>
     span(const array<_Tp, _Sz>&) -> span<const _Tp, _Sz>;
 
-#if !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template<ranges::contiguous_range _Range>
     span(_Range&&) -> span<remove_reference_t<ranges::range_reference_t<_Range>>>;
 #endif
diff --git a/libcxx/include/string_view b/libcxx/include/string_view
--- a/libcxx/include/string_view
+++ b/libcxx/include/string_view
@@ -286,7 +286,7 @@
 #endif
     }
 
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
       requires (is_same_v<iter_value_t<_It>, _CharT> && !is_convertible_v<_End, size_type>)
     constexpr _LIBCPP_HIDE_FROM_ABI basic_string_view(_It __begin, _End __end)
@@ -296,7 +296,7 @@
     }
 #endif
 
-#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
     template <class _Range>
       requires (
         !is_same_v<remove_cvref_t<_Range>, basic_string_view> &&
@@ -707,23 +707,23 @@
     size_type           __size;
 };
 
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template <class _CharT, class _Traits>
 inline constexpr bool ranges::enable_view<basic_string_view<_CharT, _Traits>> = true;
 
 template <class _CharT, class _Traits>
 inline constexpr bool ranges::enable_borrowed_range<basic_string_view<_CharT, _Traits> > = true;
-#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 
 // [string.view.deduct]
 
-#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template <contiguous_iterator _It, sized_sentinel_for<_It> _End>
   basic_string_view(_It, _End) -> basic_string_view<iter_value_t<_It>>;
 #endif
 
 
-#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_CONCEPTS)
+#if _LIBCPP_STD_VER > 20 && !defined(_LIBCPP_HAS_NO_CONCEPTS) && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
 template <ranges::contiguous_range _Range>
   basic_string_view(_Range) -> basic_string_view<ranges::range_value_t<_Range>>;
 #endif
diff --git a/libcxx/test/libcxx/ranges/has-no-incomplete-ranges.compile.pass.cpp b/libcxx/test/libcxx/ranges/has-no-incomplete-ranges.compile.pass.cpp
new file mode 100644
--- /dev/null
+++ b/libcxx/test/libcxx/ranges/has-no-incomplete-ranges.compile.pass.cpp
@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// UNSUPPORTED: c++03, c++11, c++14, c++17
+// REQUIRES: libcpp-has-no-incomplete-ranges
+
+// Test that _LIBCPP_HAS_NO_INCOMPLETE_RANGES disables the std::ranges namespace.
+
+#include <algorithm>
+#include <concepts>
+#include <filesystem>
+#include <iterator>
+#include <memory>
+#include <numeric>
+#include <ranges>
+#include <span>
+#include <string_view>
+#include <utility>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+  int views;
+  int ranges;
+
+_LIBCPP_END_NAMESPACE_STD
diff --git a/libcxx/test/std/iterators/predef.iterators/counted.iterator/iter_move.pass.cpp b/libcxx/test/std/iterators/predef.iterators/counted.iterator/iter_move.pass.cpp
--- a/libcxx/test/std/iterators/predef.iterators/counted.iterator/iter_move.pass.cpp
+++ b/libcxx/test/std/iterators/predef.iterators/counted.iterator/iter_move.pass.cpp
@@ -8,6 +8,7 @@
 
 // UNSUPPORTED: c++03, c++11, c++14, c++17
 // UNSUPPORTED: libcpp-no-concepts
+// UNSUPPORTED: libcpp-no-incomplete-ranges
 
 // friend constexpr iter_rvalue_reference_t<I>
 //   iter_move(const counted_iterator& i)