This adds adds four macros when compiling using GTEST_OS_MAC:

testing/gtest_mac.h

+// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef TESTING_GTEST_MAC_H_
+#define TESTING_GTEST_MAC_H_
+
+#include <gtest/internal/gtest-port.h>
+#include <gtest/gtest.h>
+
+#ifdef GTEST_OS_MAC
+
+#import <Foundation/Foundation.h>
+
+namespace testing {
+namespace internal {
+
+// This overloaded version allows comparison between ObjC objects that conform
+// to the NSObject protocol. Used to implement {ASSERT|EXPECT}_EQ().
+GTEST_API_ AssertionResult CmpHelperNSEQ(const char* expected_expression,
+                                         const char* actual_expression,
+                                         id<NSObject> expected,
+                                         id<NSObject> actual);
+
+// This overloaded version allows comparison between ObjC objects that conform
+// to the NSObject protocol. Used to implement {ASSERT|EXPECT}_NE().
+GTEST_API_ AssertionResult CmpHelperNSNE(const char* expected_expression,
+                                         const char* actual_expression,
+                                         id<NSObject> expected,
+                                         id<NSObject> actual);
+
+}  // namespace internal
+}  // namespace testing
+
+// Tests that [expected isEqual:actual].
+#define EXPECT_NSEQ(expected, actual) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperNSEQ, expected, actual)
+#define EXPECT_NSNE(val1, val2) \
+  EXPECT_PRED_FORMAT2(::testing::internal::CmpHelperNSNE, val1, val2)
+
+#define ASSERT_NSEQ(expected, actual) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperNSEQ, expected, actual)
+#define ASSERT_NSNE(val1, val2) \
+  ASSERT_PRED_FORMAT2(::testing::internal::CmpHelperNSNE, val1, val2)
+
+#endif  // GTEST_OS_MAC
+
+#endif  // TESTING_GTEST_MAC_H_