Export of internal Abseil changes

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0f6565955231dc74ebad62ef32a18c457afa2dc7 by Abseil Team <absl-team@google.com>:

Document guarantee that we do not move from rvalue arguments if no insertion happens with absl::raw_hash_map::try_emplace, as done with std::unordered_map::try_emplace.

PiperOrigin-RevId: 264430409

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292e6b9e08fa689e8400d7f2db94cbcab29d5889 by CJ Johnson <johnsoncj@google.com>:

Removes use of aligned_storage in FixedArray and InlinedVector in favor of aligned char buffers.

PiperOrigin-RevId: 264385559

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aa0b19ad11ae5702022feee0e2e6434cfb28c9e9 by Derek Mauro <dmauro@google.com>:

Make the unit tests for absl::any, absl::optional, and absl::variant
no-ops when these types are just aliases for the corresponding std::
types. We have no way to fix standard library implementation bugs, so
don't bother working around them.

Also disable the corresponding exception-safety tests as well when
exceptions are not enabled.

Fixes https://github.com/abseil/abseil-cpp/pull/360

PiperOrigin-RevId: 264382050

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65896a911f36481b89b4712c83b91c90a76b64e8 by Abseil Team <absl-team@google.com>:

Improve documentation on erase

PiperOrigin-RevId: 264381266
GitOrigin-RevId: 0f6565955231dc74ebad62ef32a18c457afa2dc7
Change-Id: I74b9bd2ddf84526014104f17e87de70bd3fe65fa

1 files changed, 41 insertions, 0 deletions

diff --git a/absl/container/internal/unordered_map_modifiers_test.h b/absl/container/internal/unordered_map_modifiers_test.h
index 52a1092e6b22..f6aff5422b41 100644
--- a/absl/container/internal/unordered_map_modifiers_test.h
+++ b/absl/container/internal/unordered_map_modifiers_test.h
@@ -15,6 +15,8 @@
 #ifndef ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_MODIFIERS_TEST_H_
 #define ABSL_CONTAINER_INTERNAL_UNORDERED_MAP_MODIFIERS_TEST_H_
 
+#include <memory>
+
 #include "gmock/gmock.h"
 #include "gtest/gtest.h"
 #include "absl/container/internal/hash_generator_testing.h"
@@ -267,6 +269,45 @@ REGISTER_TYPED_TEST_CASE_P(ModifiersTest, Clear, Insert, InsertHint,
                            Emplace, EmplaceHint, TryEmplace, TryEmplaceHint,
                            Erase, EraseRange, EraseKey, Swap);
 
+template <typename Type>
+struct is_unique_ptr : std::false_type {};
+
+template <typename Type>
+struct is_unique_ptr<std::unique_ptr<Type>> : std::true_type {};
+
+template <class UnordMap>
+class UniquePtrModifiersTest : public ::testing::Test {
+ protected:
+  UniquePtrModifiersTest() {
+    static_assert(is_unique_ptr<typename UnordMap::mapped_type>::value,
+                  "UniquePtrModifiersTyest may only be called with a "
+                  "std::unique_ptr value type.");
+  }
+};
+
+TYPED_TEST_SUITE_P(UniquePtrModifiersTest);
+
+// Test that we do not move from rvalue arguments if an insertion does not
+// happen.
+TYPED_TEST_P(UniquePtrModifiersTest, TryEmplace) {
+#ifdef UNORDERED_MAP_CXX17
+  using T = hash_internal::GeneratedType<TypeParam>;
+  using V = typename TypeParam::mapped_type;
+  T val = hash_internal::Generator<T>()();
+  TypeParam m;
+  auto p = m.try_emplace(val.first, std::move(val.second));
+  EXPECT_TRUE(p.second);
+  // A moved from std::unique_ptr is guaranteed to be nullptr.
+  EXPECT_EQ(val.second, nullptr);
+  T val2 = {val.first, hash_internal::Generator<V>()()};
+  p = m.try_emplace(val2.first, std::move(val2.second));
+  EXPECT_FALSE(p.second);
+  EXPECT_NE(val2.second, nullptr);
+#endif
+}
+
+REGISTER_TYPED_TEST_SUITE_P(UniquePtrModifiersTest, TryEmplace);
+
 }  // namespace container_internal
 }  // namespace absl