2 files changed, 33 insertions, 3 deletions
diff --git a/absl/container/internal/container_memory.h b/absl/container/internal/container_memory.h
index 55b59c7f..3487ac18 100644
--- a/absl/container/internal/container_memory.h
+++ b/absl/container/internal/container_memory.h
@@ -31,6 +31,7 @@
 #include <utility>
 
 #include "absl/memory/memory.h"
+#include "absl/meta/type_traits.h"
 #include "absl/utility/utility.h"
 
 namespace absl {
@@ -319,11 +320,12 @@ union map_slot_type {
   map_slot_type() {}
   ~map_slot_type() = delete;
   using value_type = std::pair<const K, V>;
-  using mutable_value_type = std::pair<K, V>;
+  using mutable_value_type =
+      std::pair<absl::remove_const_t<K>, absl::remove_const_t<V>>;
 
   value_type value;
   mutable_value_type mutable_value;
-  K key;
+  absl::remove_const_t<K> key;
 };
 
 template <class K, class V>
diff --git a/absl/container/internal/container_memory_test.cc b/absl/container/internal/container_memory_test.cc
index e3262e3c..6a7fcd29 100644
--- a/absl/container/internal/container_memory_test.cc
+++ b/absl/container/internal/container_memory_test.cc
@@ -22,6 +22,7 @@
 
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
+#include "absl/container/internal/test_instance_tracker.h"
 #include "absl/strings/string_view.h"
 
 namespace absl {
@@ -29,9 +30,11 @@ ABSL_NAMESPACE_BEGIN
 namespace container_internal {
 namespace {
 
-using ::testing::Gt;
+using ::absl::test_internal::CopyableMovableInstance;
+using ::absl::test_internal::InstanceTracker;
 using ::testing::_;
 using ::testing::ElementsAre;
+using ::testing::Gt;
 using ::testing::Pair;
 
 TEST(Memory, AlignmentLargerThanBase) {
@@ -222,6 +225,31 @@ TEST(DecomposePair, NotDecomposable) {
                                 std::make_tuple(0.5)));
 }
 
+TEST(MapSlotPolicy, ConstKeyAndValue) {
+  using slot_policy = map_slot_policy<const CopyableMovableInstance,
+                                      const CopyableMovableInstance>;
+  using slot_type = typename slot_policy::slot_type;
+
+  union Slots {
+    Slots() {}
+    ~Slots() {}
+    slot_type slots[100];
+  } slots;
+
+  std::allocator<
+      std::pair<const CopyableMovableInstance, const CopyableMovableInstance>>
+      alloc;
+  InstanceTracker tracker;
+  slot_policy::construct(&alloc, &slots.slots[0], CopyableMovableInstance(1),
+                         CopyableMovableInstance(1));
+  for (int i = 0; i < 99; ++i) {
+    slot_policy::transfer(&alloc, &slots.slots[i + 1], &slots.slots[i]);
+  }
+  slot_policy::destroy(&alloc, &slots.slots[99]);
+
+  EXPECT_EQ(tracker.copies(), 0);
+}
+
 }  // namespace
 }  // namespace container_internal
 ABSL_NAMESPACE_END