Add base::get to support rvalue-reference tuple

base/tuple_unittest.cc

Index: base/tuple_unittest.cc
diff --git a/base/tuple_unittest.cc b/base/tuple_unittest.cc
index 815b43bb1b3236b10cc5a142b4d5ef1e264d84b1..6f90c2922064610cb7426cad5095cc2bc042a01f 100644
--- a/base/tuple_unittest.cc
+++ b/base/tuple_unittest.cc
@@ -114,4 +114,30 @@ TEST(TupleTest, Copying) {
   EXPECT_EQ(2, CopyLogger::TimesCopied);
 }
 
+TEST(TupleTest, Get) {
+  int i = 1;
+  int j = 2;
+  std::tuple<int, int&, int&&> t(3, i, std::move(j));
+  EXPECT_TRUE((std::is_same<int&, decltype(base::get<0>(t))>::value));
+  EXPECT_EQ(3, base::get<0>(t));
+
+  EXPECT_TRUE((std::is_same<int&, decltype(base::get<1>(t))>::value));
+  EXPECT_EQ(1, base::get<1>(t));
+
+  EXPECT_TRUE((std::is_same<int&, decltype(base::get<2>(t))>::value));
+  EXPECT_EQ(2, base::get<2>(t));
+
+  EXPECT_TRUE((std::is_same<int&&,
+               decltype(base::get<0>(std::move(t)))>::value));
+  EXPECT_EQ(3, base::get<0>(std::move(t)));
+
+  EXPECT_TRUE((std::is_same<int&,
+               decltype(base::get<1>(std::move(t)))>::value));
+  EXPECT_EQ(1, base::get<1>(std::move(t)));
+
+  EXPECT_TRUE((std::is_same<int&&,
+               decltype(base::get<2>(std::move(t)))>::value));
+  EXPECT_EQ(2, base::get<2>(std::move(t)));
+}
+
 }  // namespace base