Export of internal Abseil changes.

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c1f3a243ff3713917eaf0255c86ddd1b40461ba9 by Abseil Team <absl-team@google.com>:

Remove stray space.

PiperOrigin-RevId: 207753171

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4abe43b174f7fafa390d2f6eb96f31977a38fc69 by Shaindel Schwartz <shaindel@google.com>:

Typo fix.

PiperOrigin-RevId: 207572868

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e7757b409256b025cadba20a84a93cb9dc4319e1 by Abseil Team <absl-team@google.com>:

Adds backported is_(copy|move)_assignable<T>

PiperOrigin-RevId: 207572180
GitOrigin-RevId: c1f3a243ff3713917eaf0255c86ddd1b40461ba9
Change-Id: I1202715e5092b54d5967017728044715d6eb2ec0

1 files changed, 76 insertions, 0 deletions

diff --git a/absl/meta/type_traits_test.cc b/absl/meta/type_traits_test.cc
index 81b4bd3..f51f5de 100644
--- a/absl/meta/type_traits_test.cc
+++ b/absl/meta/type_traits_test.cc
@@ -877,4 +877,80 @@ TEST(TypeTraitsTest, TestResultOf) {
   EXPECT_EQ(TypeEnum::D, GetTypeExt(Wrap<TypeD>()));
 }
 
+template <typename T>
+bool TestCopyAssign() {
+  return absl::is_copy_assignable<T>::value ==
+         std::is_copy_assignable<T>::value;
+}
+
+TEST(TypeTraitsTest, IsCopyAssignable) {
+  EXPECT_TRUE(TestCopyAssign<int>());
+  EXPECT_TRUE(TestCopyAssign<int&>());
+  EXPECT_TRUE(TestCopyAssign<int&&>());
+
+  struct S {};
+  EXPECT_TRUE(TestCopyAssign<S>());
+  EXPECT_TRUE(TestCopyAssign<S&>());
+  EXPECT_TRUE(TestCopyAssign<S&&>());
+
+  class C {
+   public:
+    explicit C(C* c) : c_(c) {}
+    ~C() { delete c_; }
+
+   private:
+    C* c_;
+  };
+  EXPECT_TRUE(TestCopyAssign<C>());
+  EXPECT_TRUE(TestCopyAssign<C&>());
+  EXPECT_TRUE(TestCopyAssign<C&&>());
+
+  // Reason for ifndef: add_lvalue_reference<T> in libc++ breaks for these cases
+#ifndef _LIBCPP_VERSION
+  EXPECT_TRUE(TestCopyAssign<int()>());
+  EXPECT_TRUE(TestCopyAssign<int(int) const>());
+  EXPECT_TRUE(TestCopyAssign<int(...) volatile&>());
+  EXPECT_TRUE(TestCopyAssign<int(int, ...) const volatile&&>());
+#endif  // _LIBCPP_VERSION
+}
+
+template <typename T>
+bool TestMoveAssign() {
+  return absl::is_move_assignable<T>::value ==
+         std::is_move_assignable<T>::value;
+}
+
+TEST(TypeTraitsTest, IsMoveAssignable) {
+  EXPECT_TRUE(TestMoveAssign<int>());
+  EXPECT_TRUE(TestMoveAssign<int&>());
+  EXPECT_TRUE(TestMoveAssign<int&&>());
+
+  struct S {};
+  EXPECT_TRUE(TestMoveAssign<S>());
+  EXPECT_TRUE(TestMoveAssign<S&>());
+  EXPECT_TRUE(TestMoveAssign<S&&>());
+
+  class C {
+   public:
+    explicit C(C* c) : c_(c) {}
+    ~C() { delete c_; }
+    void operator=(const C&) = delete;
+    void operator=(C&&) = delete;
+
+   private:
+    C* c_;
+  };
+  EXPECT_TRUE(TestMoveAssign<C>());
+  EXPECT_TRUE(TestMoveAssign<C&>());
+  EXPECT_TRUE(TestMoveAssign<C&&>());
+
+  // Reason for ifndef: add_lvalue_reference<T> in libc++ breaks for these cases
+#ifndef _LIBCPP_VERSION
+  EXPECT_TRUE(TestMoveAssign<int()>());
+  EXPECT_TRUE(TestMoveAssign<int(int) const>());
+  EXPECT_TRUE(TestMoveAssign<int(...) volatile&>());
+  EXPECT_TRUE(TestMoveAssign<int(int, ...) const volatile&&>());
+#endif  // _LIBCPP_VERSION
+}
+
 }  // namespace