1 files changed, 12 insertions, 0 deletions
diff --git a/absl/container/flat_hash_set.h b/absl/container/flat_hash_set.h
index a2584d66..f7c1acaa 100644
--- a/absl/container/flat_hash_set.h
+++ b/absl/container/flat_hash_set.h
@@ -32,6 +32,7 @@
 #include <type_traits>
 #include <utility>
 
+#include "absl/algorithm/container.h"
 #include "absl/base/macros.h"
 #include "absl/container/internal/container_memory.h"
 #include "absl/container/internal/hash_function_defaults.h"  // IWYU pragma: export
@@ -475,5 +476,16 @@ struct FlatHashSetPolicy {
   static size_t space_used(const T*) { return 0; }
 };
 }  // namespace container_internal
+
+namespace container_algorithm_internal {
+
+// Specialization of trait in absl/algorithm/container.h
+template <class Key, class Hash, class KeyEqual, class Allocator>
+struct IsUnorderedContainer<absl::flat_hash_set<Key, Hash, KeyEqual, Allocator>>
+    : std::true_type {};
+
+}  // namespace container_algorithm_internal
+
 }  // namespace absl
+
 #endif  // ABSL_CONTAINER_FLAT_HASH_SET_H_