Export of internal Abseil changes

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44b312da54263fc7491b5f1e115e49e0c1e2dc10 by Greg Falcon <gfalcon@google.com>:

Import of CCTZ from GitHub.

PiperOrigin-RevId: 315782632

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27618a3b195f75384ba44e9712ae0b0b7d85937e by Greg Falcon <gfalcon@google.com>:

Update Abseil's internal Invoke() implementation to follow C++17 semantics.

Starting in C++17, when invoke'ing a pointer-to-member, if the object representing the class is a reference_wrapper, that wrapper is unpacked.  Because we implement a number of functional APIs that closely match C++ standard proposals, it is better if we follow the standard's notion of what "invoking" means.

This also makes `absl::base_internal::Invoke()` match `std::invoke()` in C++17.  I intend to make this an alias in a follow-up CL.

PiperOrigin-RevId: 315750659

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059519ea402cd55b1b716403bb680504c6ff5808 by Xiaoyi Zhang <zhangxy@google.com>:

Internal change

PiperOrigin-RevId: 315597064

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5e2042c8520576b2508e2bfb1020a97c7db591da by Titus Winters <titus@google.com>:

Update notes on the delta between absl::Span vs. std::span.

PiperOrigin-RevId: 315518942

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9d3875527b93124f5de5d6a1d575c42199fbf323 by Abseil Team <absl-team@google.com>:

Internal cleanup

PiperOrigin-RevId: 315497633
GitOrigin-RevId: 44b312da54263fc7491b5f1e115e49e0c1e2dc10
Change-Id: I24573f317c8388bd693c0fdab395a7dd419b33b0

1 files changed, 34 insertions, 0 deletions

diff --git a/absl/base/invoke_test.cc b/absl/base/invoke_test.cc
index 6aa613c9..994d36b9 100644
--- a/absl/base/invoke_test.cc
+++ b/absl/base/invoke_test.cc
@@ -158,31 +158,56 @@ TEST(InvokeTest, MemberFunction) {
   std::unique_ptr<const Class> cp(new Class);
   std::unique_ptr<volatile Class> vp(new Class);
 
+  Class c;
+  std::reference_wrapper<Class> ref(c);
+  std::reference_wrapper<const Class> ref_const(c);
+  const std::reference_wrapper<Class> const_ref(c);
+  std::reference_wrapper<volatile Class> ref_volatile(c);
+
   EXPECT_EQ(1, Invoke(&Class::Method, p, 3, 2));
   EXPECT_EQ(1, Invoke(&Class::Method, p.get(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::Method, *p, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::Method, ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::Method, const_ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::Method, std::move(ref), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::RefMethod, p, 3, 2));
   EXPECT_EQ(1, Invoke(&Class::RefMethod, p.get(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::RefMethod, *p, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::RefMethod, ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::RefMethod, const_ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::RefMethod, std::move(ref), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::RefRefMethod, std::move(*p), 3, 2));  // NOLINT
   EXPECT_EQ(1, Invoke(&Class::NoExceptMethod, p, 3, 2));
   EXPECT_EQ(1, Invoke(&Class::NoExceptMethod, p.get(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::NoExceptMethod, *p, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::NoExceptMethod, ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::NoExceptMethod, const_ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::NoExceptMethod, std::move(ref), 3, 2));
 
   EXPECT_EQ(1, Invoke(&Class::ConstMethod, p, 3, 2));
   EXPECT_EQ(1, Invoke(&Class::ConstMethod, p.get(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::ConstMethod, *p, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::ConstMethod, ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::ConstMethod, const_ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::ConstMethod, std::move(ref), 3, 2));
 
   EXPECT_EQ(1, Invoke(&Class::ConstMethod, cp, 3, 2));
   EXPECT_EQ(1, Invoke(&Class::ConstMethod, cp.get(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::ConstMethod, *cp, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::ConstMethod, ref_const, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::ConstMethod, std::move(ref_const), 3, 2));
 
   EXPECT_EQ(1, Invoke(&Class::VolatileMethod, p, 3, 2));
   EXPECT_EQ(1, Invoke(&Class::VolatileMethod, p.get(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::VolatileMethod, *p, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::VolatileMethod, ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::VolatileMethod, const_ref, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::VolatileMethod, std::move(ref), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::VolatileMethod, vp, 3, 2));
   EXPECT_EQ(1, Invoke(&Class::VolatileMethod, vp.get(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::VolatileMethod, *vp, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::VolatileMethod, ref_volatile, 3, 2));
+  EXPECT_EQ(1, Invoke(&Class::VolatileMethod, std::move(ref_volatile), 3, 2));
 
   EXPECT_EQ(1, Invoke(&Class::Method, make_unique<Class>(), 3, 2));
   EXPECT_EQ(1, Invoke(&Class::ConstMethod, make_unique<Class>(), 3, 2));
@@ -192,8 +217,15 @@ TEST(InvokeTest, MemberFunction) {
 TEST(InvokeTest, DataMember) {
   std::unique_ptr<Class> p(new Class{42});
   std::unique_ptr<const Class> cp(new Class{42});
+  Class c{42};
+  std::reference_wrapper<Class> ref(c);
+  std::reference_wrapper<const Class> ref_const(c);
+  const std::reference_wrapper<Class> const_ref(c);
   EXPECT_EQ(42, Invoke(&Class::member, p));
   EXPECT_EQ(42, Invoke(&Class::member, *p));
+  EXPECT_EQ(42, Invoke(&Class::member, ref));
+  EXPECT_EQ(42, Invoke(&Class::member, const_ref));
+  EXPECT_EQ(42, Invoke(&Class::member, std::move(ref)));
   EXPECT_EQ(42, Invoke(&Class::member, p.get()));
 
   Invoke(&Class::member, p) = 42;
@@ -201,6 +233,8 @@ TEST(InvokeTest, DataMember) {
 
   EXPECT_EQ(42, Invoke(&Class::member, cp));
   EXPECT_EQ(42, Invoke(&Class::member, *cp));
+  EXPECT_EQ(42, Invoke(&Class::member, ref_const));
+  EXPECT_EQ(42, Invoke(&Class::member, std::move(ref_const)));
   EXPECT_EQ(42, Invoke(&Class::member, cp.get()));
 }