Add 'third_party/abseil_cpp/' from commit '768eb2ca2857342673fcd462792ce04b8bac3fa3' r/781

git-subtree-dir: third_party/abseil_cpp
git-subtree-mainline: ffb2ae54beb5796cd408fbe15d2d2da09ff37adf
git-subtree-split: 768eb2ca2857342673fcd462792ce04b8bac3fa3

1 files changed, 257 insertions, 0 deletions

diff --git a/third_party/abseil_cpp/absl/functional/function_ref_test.cc b/third_party/abseil_cpp/absl/functional/function_ref_test.cc
new file mode 100644
index 000000000000..3aa59745873d
--- /dev/null
+++ b/third_party/abseil_cpp/absl/functional/function_ref_test.cc
@@ -0,0 +1,257 @@
+// Copyright 2019 The Abseil Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "absl/functional/function_ref.h"
+
+#include <memory>
+
+#include "gmock/gmock.h"
+#include "gtest/gtest.h"
+#include "absl/container/internal/test_instance_tracker.h"
+#include "absl/memory/memory.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace {
+
+void RunFun(FunctionRef<void()> f) { f(); }
+
+TEST(FunctionRefTest, Lambda) {
+  bool ran = false;
+  RunFun([&] { ran = true; });
+  EXPECT_TRUE(ran);
+}
+
+int Function() { return 1337; }
+
+TEST(FunctionRefTest, Function1) {
+  FunctionRef<int()> ref(&Function);
+  EXPECT_EQ(1337, ref());
+}
+
+TEST(FunctionRefTest, Function2) {
+  FunctionRef<int()> ref(Function);
+  EXPECT_EQ(1337, ref());
+}
+
+int NoExceptFunction() noexcept { return 1337; }
+
+// TODO(jdennett): Add a test for noexcept member functions.
+TEST(FunctionRefTest, NoExceptFunction) {
+  FunctionRef<int()> ref(NoExceptFunction);
+  EXPECT_EQ(1337, ref());
+}
+
+TEST(FunctionRefTest, ForwardsArgs) {
+  auto l = [](std::unique_ptr<int> i) { return *i; };
+  FunctionRef<int(std::unique_ptr<int>)> ref(l);
+  EXPECT_EQ(42, ref(absl::make_unique<int>(42)));
+}
+
+TEST(FunctionRef, ReturnMoveOnly) {
+  auto l = [] { return absl::make_unique<int>(29); };
+  FunctionRef<std::unique_ptr<int>()> ref(l);
+  EXPECT_EQ(29, *ref());
+}
+
+TEST(FunctionRef, ManyArgs) {
+  auto l = [](int a, int b, int c) { return a + b + c; };
+  FunctionRef<int(int, int, int)> ref(l);
+  EXPECT_EQ(6, ref(1, 2, 3));
+}
+
+TEST(FunctionRef, VoidResultFromNonVoidFunctor) {
+  bool ran = false;
+  auto l = [&]() -> int {
+    ran = true;
+    return 2;
+  };
+  FunctionRef<void()> ref(l);
+  ref();
+  EXPECT_TRUE(ran);
+}
+
+TEST(FunctionRef, CastFromDerived) {
+  struct Base {};
+  struct Derived : public Base {};
+
+  Derived d;
+  auto l1 = [&](Base* b) { EXPECT_EQ(&d, b); };
+  FunctionRef<void(Derived*)> ref1(l1);
+  ref1(&d);
+
+  auto l2 = [&]() -> Derived* { return &d; };
+  FunctionRef<Base*()> ref2(l2);
+  EXPECT_EQ(&d, ref2());
+}
+
+TEST(FunctionRef, VoidResultFromNonVoidFuncton) {
+  FunctionRef<void()> ref(Function);
+  ref();
+}
+
+TEST(FunctionRef, MemberPtr) {
+  struct S {
+    int i;
+  };
+
+  S s{1100111};
+  auto mem_ptr = &S::i;
+  FunctionRef<int(const S& s)> ref(mem_ptr);
+  EXPECT_EQ(1100111, ref(s));
+}
+
+TEST(FunctionRef, MemberFun) {
+  struct S {
+    int i;
+    int get_i() const { return i; }
+  };
+
+  S s{22};
+  auto mem_fun_ptr = &S::get_i;
+  FunctionRef<int(const S& s)> ref(mem_fun_ptr);
+  EXPECT_EQ(22, ref(s));
+}
+
+TEST(FunctionRef, MemberFunRefqualified) {
+  struct S {
+    int i;
+    int get_i() && { return i; }
+  };
+  auto mem_fun_ptr = &S::get_i;
+  S s{22};
+  FunctionRef<int(S && s)> ref(mem_fun_ptr);
+  EXPECT_EQ(22, ref(std::move(s)));
+}
+
+#if !defined(_WIN32) && defined(GTEST_HAS_DEATH_TEST)
+
+TEST(FunctionRef, MemberFunRefqualifiedNull) {
+  struct S {
+    int i;
+    int get_i() && { return i; }
+  };
+  auto mem_fun_ptr = &S::get_i;
+  mem_fun_ptr = nullptr;
+  EXPECT_DEBUG_DEATH({ FunctionRef<int(S && s)> ref(mem_fun_ptr); }, "");
+}
+
+TEST(FunctionRef, NullMemberPtrAssertFails) {
+  struct S {
+    int i;
+  };
+  using MemberPtr = int S::*;
+  MemberPtr mem_ptr = nullptr;
+  EXPECT_DEBUG_DEATH({ FunctionRef<int(const S& s)> ref(mem_ptr); }, "");
+}
+
+#endif  // GTEST_HAS_DEATH_TEST
+
+TEST(FunctionRef, CopiesAndMovesPerPassByValue) {
+  absl::test_internal::InstanceTracker tracker;
+  absl::test_internal::CopyableMovableInstance instance(0);
+  auto l = [](absl::test_internal::CopyableMovableInstance) {};
+  FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
+  ref(instance);
+  EXPECT_EQ(tracker.copies(), 1);
+  EXPECT_EQ(tracker.moves(), 1);
+}
+
+TEST(FunctionRef, CopiesAndMovesPerPassByRef) {
+  absl::test_internal::InstanceTracker tracker;
+  absl::test_internal::CopyableMovableInstance instance(0);
+  auto l = [](const absl::test_internal::CopyableMovableInstance&) {};
+  FunctionRef<void(const absl::test_internal::CopyableMovableInstance&)> ref(l);
+  ref(instance);
+  EXPECT_EQ(tracker.copies(), 0);
+  EXPECT_EQ(tracker.moves(), 0);
+}
+
+TEST(FunctionRef, CopiesAndMovesPerPassByValueCallByMove) {
+  absl::test_internal::InstanceTracker tracker;
+  absl::test_internal::CopyableMovableInstance instance(0);
+  auto l = [](absl::test_internal::CopyableMovableInstance) {};
+  FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
+  ref(std::move(instance));
+  EXPECT_EQ(tracker.copies(), 0);
+  EXPECT_EQ(tracker.moves(), 2);
+}
+
+TEST(FunctionRef, CopiesAndMovesPerPassByValueToRef) {
+  absl::test_internal::InstanceTracker tracker;
+  absl::test_internal::CopyableMovableInstance instance(0);
+  auto l = [](const absl::test_internal::CopyableMovableInstance&) {};
+  FunctionRef<void(absl::test_internal::CopyableMovableInstance)> ref(l);
+  ref(std::move(instance));
+  EXPECT_EQ(tracker.copies(), 0);
+  EXPECT_EQ(tracker.moves(), 1);
+}
+
+TEST(FunctionRef, PassByValueTypes) {
+  using absl::functional_internal::Invoker;
+  using absl::functional_internal::VoidPtr;
+  using absl::test_internal::CopyableMovableInstance;
+  struct Trivial {
+    void* p[2];
+  };
+  struct LargeTrivial {
+    void* p[3];
+  };
+
+  static_assert(std::is_same<Invoker<void, int>, void (*)(VoidPtr, int)>::value,
+                "Scalar types should be passed by value");
+  static_assert(
+      std::is_same<Invoker<void, Trivial>, void (*)(VoidPtr, Trivial)>::value,
+      "Small trivial types should be passed by value");
+  static_assert(std::is_same<Invoker<void, LargeTrivial>,
+                             void (*)(VoidPtr, LargeTrivial &&)>::value,
+                "Large trivial types should be passed by rvalue reference");
+  static_assert(
+      std::is_same<Invoker<void, CopyableMovableInstance>,
+                   void (*)(VoidPtr, CopyableMovableInstance &&)>::value,
+      "Types with copy/move ctor should be passed by rvalue reference");
+
+  // References are passed as references.
+  static_assert(
+      std::is_same<Invoker<void, int&>, void (*)(VoidPtr, int&)>::value,
+      "Reference types should be preserved");
+  static_assert(
+      std::is_same<Invoker<void, CopyableMovableInstance&>,
+                   void (*)(VoidPtr, CopyableMovableInstance&)>::value,
+      "Reference types should be preserved");
+  static_assert(
+      std::is_same<Invoker<void, CopyableMovableInstance&&>,
+                   void (*)(VoidPtr, CopyableMovableInstance &&)>::value,
+      "Reference types should be preserved");
+
+  // Make sure the address of an object received by reference is the same as the
+  // addess of the object passed by the caller.
+  {
+    LargeTrivial obj;
+    auto test = [&obj](LargeTrivial& input) { ASSERT_EQ(&input, &obj); };
+    absl::FunctionRef<void(LargeTrivial&)> ref(test);
+    ref(obj);
+  }
+
+  {
+    Trivial obj;
+    auto test = [&obj](Trivial& input) { ASSERT_EQ(&input, &obj); };
+    absl::FunctionRef<void(Trivial&)> ref(test);
+    ref(obj);
+  }
+}
+
+}  // namespace
+ABSL_NAMESPACE_END
+}  // namespace absl