diff --git a/libcxx/test/std/containers/associative/multimap/scary.pass.cpp b/libcxx/test/libcxx/containers/associative/map/scary.compile.pass.cpp
similarity index 68%
rename from libcxx/test/std/containers/associative/multimap/scary.pass.cpp
rename to libcxx/test/libcxx/containers/associative/map/scary.compile.pass.cpp
index 2390d8fed3350..89e753f854926 100644
--- a/libcxx/test/std/containers/associative/multimap/scary.pass.cpp
+++ b/libcxx/test/libcxx/containers/associative/map/scary.compile.pass.cpp
@@ -8,20 +8,19 @@
 
 // <map>
 
-// class map class multimap
+// class map
+// class multimap
 
-// Extension:  SCARY/N2913 iterator compatibility between map and multimap
+// Extension: SCARY/N2913 iterator compatibility between map and multimap
 
 #include <map>
 
 #include "test_macros.h"
 
-int main(int, char**) {
+void test() {
   typedef std::map<int, int> M1;
   typedef std::multimap<int, int> M2;
-  M2::iterator i;
-  M1::iterator j = i;
-  ((void)j);
 
-  return 0;
+  ASSERT_SAME_TYPE(M1::iterator, M2::iterator);
+  ASSERT_SAME_TYPE(M1::const_iterator, M2::const_iterator);
 }
diff --git a/libcxx/test/std/containers/associative/multiset/scary.pass.cpp b/libcxx/test/libcxx/containers/associative/set/scary.compile.pass.cpp
similarity index 68%
rename from libcxx/test/std/containers/associative/multiset/scary.pass.cpp
rename to libcxx/test/libcxx/containers/associative/set/scary.compile.pass.cpp
index 4d30c27733647..87ed05d84cdd7 100644
--- a/libcxx/test/std/containers/associative/multiset/scary.pass.cpp
+++ b/libcxx/test/libcxx/containers/associative/set/scary.compile.pass.cpp
@@ -8,20 +8,19 @@
 
 // <set>
 
-// class set class multiset
+// class set
+// class multiset
 
-// Extension:  SCARY/N2913 iterator compatibility between set and multiset
+// Extension: SCARY/N2913 iterator compatibility between set and multiset
 
 #include <set>
 
 #include "test_macros.h"
 
-int main(int, char**) {
+void test() {
   typedef std::set<int> M1;
   typedef std::multiset<int> M2;
-  M2::iterator i;
-  M1::iterator j = i;
-  ((void)j);
 
-  return 0;
+  ASSERT_SAME_TYPE(M1::iterator, M2::iterator);
+  ASSERT_SAME_TYPE(M1::const_iterator, M2::const_iterator);
 }
diff --git a/libcxx/test/std/containers/unord/unord.multimap/scary.pass.cpp b/libcxx/test/libcxx/containers/associative/unord.map/scary.compile.pass.cpp
similarity index 57%
rename from libcxx/test/std/containers/unord/unord.multimap/scary.pass.cpp
rename to libcxx/test/libcxx/containers/associative/unord.map/scary.compile.pass.cpp
index 59ade49434ca9..db2ef33b6ebf8 100644
--- a/libcxx/test/std/containers/unord/unord.multimap/scary.pass.cpp
+++ b/libcxx/test/libcxx/containers/associative/unord.map/scary.compile.pass.cpp
@@ -8,20 +8,21 @@
 
 // <unordered_map>
 
-// class unordered_map class unordered_multimap
+// class unordered_map
+// class unordered_multimap
 
-// Extension:  SCARY/N2913 iterator compatibility between unordered_map and unordered_multimap
+// Extension: SCARY/N2913 iterator compatibility between unordered_map and unordered_multimap
 
 #include <unordered_map>
 
 #include "test_macros.h"
 
-int main(int, char**) {
+void test() {
   typedef std::unordered_map<int, int> M1;
   typedef std::unordered_multimap<int, int> M2;
-  M2::iterator i;
-  M1::iterator j = i;
-  ((void)j);
 
-  return 0;
+  ASSERT_SAME_TYPE(M1::iterator, M2::iterator);
+  ASSERT_SAME_TYPE(M1::const_iterator, M2::const_iterator);
+  ASSERT_SAME_TYPE(M1::local_iterator, M2::local_iterator);
+  ASSERT_SAME_TYPE(M1::const_local_iterator, M2::const_local_iterator);
 }
diff --git a/libcxx/test/std/containers/unord/unord.multiset/scary.pass.cpp b/libcxx/test/libcxx/containers/associative/unord.set/scary.compile.pass.cpp
similarity index 56%
rename from libcxx/test/std/containers/unord/unord.multiset/scary.pass.cpp
rename to libcxx/test/libcxx/containers/associative/unord.set/scary.compile.pass.cpp
index 89f575bc2d790..cd33e1a91ec16 100644
--- a/libcxx/test/std/containers/unord/unord.multiset/scary.pass.cpp
+++ b/libcxx/test/libcxx/containers/associative/unord.set/scary.compile.pass.cpp
@@ -8,20 +8,21 @@
 
 // <unordered_set>
 
-// class unordered_set class unordered_multiset
+// class unordered_set
+// class unordered_multiset
 
-// Extension:  SCARY/N2913 iterator compatibility between unordered_set and unordered_multiset
+// Extension: SCARY/N2913 iterator compatibility between unordered_set and unordered_multiset
 
 #include <unordered_set>
 
 #include "test_macros.h"
 
-int main(int, char**) {
+void test() {
   typedef std::unordered_set<int> M1;
   typedef std::unordered_multiset<int> M2;
-  M2::iterator i;
-  M1::iterator j = i;
-  ((void)j);
 
-  return 0;
+  ASSERT_SAME_TYPE(M1::iterator, M2::iterator);
+  ASSERT_SAME_TYPE(M1::const_iterator, M2::const_iterator);
+  ASSERT_SAME_TYPE(M1::local_iterator, M2::local_iterator);
+  ASSERT_SAME_TYPE(M1::const_local_iterator, M2::const_local_iterator);
 }
diff --git a/libcxx/test/libcxx/containers/container.adaptors/flat.map/scary.compile.pass.cpp b/libcxx/test/libcxx/containers/container.adaptors/flat.map/scary.compile.pass.cpp
new file mode 100644
index 0000000000000..3fff89cd90acf
--- /dev/null
+++ b/libcxx/test/libcxx/containers/container.adaptors/flat.map/scary.compile.pass.cpp
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+// 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, c++20
+
+// <flat_map>
+
+// class flat_map
+// class flat_multimap
+
+// Extension: SCARY/N2913 iterator compatibility between flat_map and flat_multimap
+// Test for the absence of this feature
+
+#include <flat_map>
+#include <type_traits>
+
+#include "test_macros.h"
+
+void test() {
+  typedef std::flat_map<int, int> M1;
+  typedef std::flat_multimap<int, int> M2;
+
+  static_assert(!std::is_convertible_v<M1::iterator, M2::iterator>);
+  static_assert(!std::is_convertible_v<M2::iterator, M1::iterator>);
+
+  static_assert(!std::is_convertible_v<M1::const_iterator, M2::const_iterator>);
+  static_assert(!std::is_convertible_v<M2::const_iterator, M1::const_iterator>);
+}