remove custom implementations of std::is_same

googletest/include/gtest/gtest-matchers.h

@@ -42,6 +42,7 @@
 #include <memory>
 #include <ostream>
 #include <string>
+#include <type_traits>
 
 #include "gtest/gtest-printers.h"
 #include "gtest/internal/gtest-internal.h"
@@ -299,8 +300,8 @@ class MatcherBase {
   template <typename U>
   explicit MatcherBase(
       const MatcherInterface<U>* impl,
-      typename internal::EnableIf<
-          !internal::IsSame<U, const U&>::value>::type* = nullptr)
+      typename internal::EnableIf<!std::is_same<U, const U&>::value>::type* =
+          nullptr)
       : impl_(new internal::MatcherInterfaceAdapter<U>(impl)) {}
 
   MatcherBase(const MatcherBase&) = default;
@@ -333,9 +334,10 @@ class Matcher : public internal::MatcherBase<T> {
       : internal::MatcherBase<T>(impl) {}
 
   template <typename U>
-  explicit Matcher(const MatcherInterface<U>* impl,
-                   typename internal::EnableIf<
-                       !internal::IsSame<U, const U&>::value>::type* = nullptr)
+  explicit Matcher(
+      const MatcherInterface<U>* impl,
+      typename internal::EnableIf<!std::is_same<U, const U&>::value>::type* =
+          nullptr)
       : internal::MatcherBase<T>(impl) {}
 
   // Implicit constructor here allows people to write

googletest/include/gtest/internal/gtest-internal.h

@@ -977,9 +977,9 @@ template <typename C>
 struct IsRecursiveContainerImpl<C, true> {
   using value_type = decltype(*std::declval<typename C::const_iterator>());
   using type =
-      is_same<typename std::remove_const<
-                  typename std::remove_reference<value_type>::type>::type,
-              C>;
+      std::is_same<typename std::remove_const<
+                       typename std::remove_reference<value_type>::type>::type,
+                   C>;
 };
 
 // IsRecursiveContainer<Type> is a unary compile-time predicate that

googletest/include/gtest/internal/gtest-port.h

@@ -869,16 +869,6 @@ struct StaticAssertTypeEqHelper<T, T> {
   enum { value = true };
 };
 
-// Same as std::is_same<>.
-template <typename T, typename U>
-struct IsSame {
-  enum { value = false };
-};
-template <typename T>
-struct IsSame<T, T> {
-  enum { value = true };
-};
-
 // Evaluates to the number of elements in 'array'.
 #define GTEST_ARRAY_SIZE_(array) (sizeof(array) / sizeof(array[0]))
 
@@ -1931,12 +1921,6 @@ template <bool bool_value> const bool bool_constant<bool_value>::value;
 typedef bool_constant<false> false_type;
 typedef bool_constant<true> true_type;
 
-template <typename T, typename U>
-struct is_same : public false_type {};
-
-template <typename T>
-struct is_same<T, T> : public true_type {};
-
 template <typename Iterator>
 struct IteratorTraits {
   typedef typename Iterator::value_type value_type;

googletest/test/googletest-output-test_.cc

@@ -816,9 +816,9 @@ class TypedTestNames {
  public:
   template <typename T>
   static std::string GetName(int i) {
-    if (testing::internal::IsSame<T, char>::value)
+    if (std::is_same<T, char>::value)
       return std::string("char") + ::testing::PrintToString(i);
-    if (testing::internal::IsSame<T, int>::value)
+    if (std::is_same<T, int>::value)
       return std::string("int") + ::testing::PrintToString(i);
   }
 };
@@ -857,10 +857,10 @@ class TypedTestPNames {
  public:
   template <typename T>
   static std::string GetName(int i) {
-    if (testing::internal::IsSame<T, unsigned char>::value) {
+    if (std::is_same<T, unsigned char>::value) {
       return std::string("unsignedChar") + ::testing::PrintToString(i);
     }
-    if (testing::internal::IsSame<T, unsigned int>::value) {
+    if (std::is_same<T, unsigned int>::value) {
       return std::string("unsignedInt") + ::testing::PrintToString(i);
     }
   }

googletest/test/gtest-typed-test_test.cc

@@ -31,6 +31,7 @@
 #include "test/gtest-typed-test_test.h"
 
 #include <set>
+#include <type_traits>
 #include <vector>
 
 #include "gtest/gtest.h"
@@ -177,10 +178,10 @@ class TypedTestNames {
  public:
   template <typename T>
   static std::string GetName(int i) {
-    if (testing::internal::IsSame<T, char>::value) {
+    if (std::is_same<T, char>::value) {
       return std::string("char") + ::testing::PrintToString(i);
     }
-    if (testing::internal::IsSame<T, int>::value) {
+    if (std::is_same<T, int>::value) {
       return std::string("int") + ::testing::PrintToString(i);
     }
   }
@@ -189,13 +190,13 @@ class TypedTestNames {
 TYPED_TEST_SUITE(TypedTestWithNames, TwoTypes, TypedTestNames);
 
 TYPED_TEST(TypedTestWithNames, TestSuiteName) {
-  if (testing::internal::IsSame<TypeParam, char>::value) {
+  if (std::is_same<TypeParam, char>::value) {
     EXPECT_STREQ(::testing::UnitTest::GetInstance()
                      ->current_test_info()
                      ->test_case_name(),
                  "TypedTestWithNames/char0");
   }
-  if (testing::internal::IsSame<TypeParam, int>::value) {
+  if (std::is_same<TypeParam, int>::value) {
     EXPECT_STREQ(::testing::UnitTest::GetInstance()
                      ->current_test_info()
                      ->test_case_name(),
@@ -311,13 +312,13 @@ class TypeParametrizedTestWithNames : public Test {};
 TYPED_TEST_SUITE_P(TypeParametrizedTestWithNames);
 
 TYPED_TEST_P(TypeParametrizedTestWithNames, TestSuiteName) {
-  if (testing::internal::IsSame<TypeParam, char>::value) {
+  if (std::is_same<TypeParam, char>::value) {
     EXPECT_STREQ(::testing::UnitTest::GetInstance()
                      ->current_test_info()
                      ->test_case_name(),
                  "CustomName/TypeParametrizedTestWithNames/parChar0");
   }
-  if (testing::internal::IsSame<TypeParam, int>::value) {
+  if (std::is_same<TypeParam, int>::value) {
     EXPECT_STREQ(::testing::UnitTest::GetInstance()
                      ->current_test_info()
                      ->test_case_name(),
@@ -331,10 +332,10 @@ class TypeParametrizedTestNames {
  public:
   template <typename T>
   static std::string GetName(int i) {
-    if (testing::internal::IsSame<T, char>::value) {
+    if (std::is_same<T, char>::value) {
       return std::string("parChar") + ::testing::PrintToString(i);
     }
-    if (testing::internal::IsSame<T, int>::value) {
+    if (std::is_same<T, int>::value) {
       return std::string("parInt") + ::testing::PrintToString(i);
     }
   }