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+// Copyright 2008 Google Inc.
+// All Rights Reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+//
+// Author: wan@google.com (Zhanyong Wan)
+
+// This sample shows how to test common properties of multiple
+// implementations of the same interface (aka interface tests).
+
+// The interface and its implementations are in this header.
+#include "prime_tables.h"
+
+#include "gtest/gtest.h"
+
+// First, we define some factory functions for creating instances of
+// the implementations.  You may be able to skip this step if all your
+// implementations can be constructed the same way.
+
+template <class T>
+PrimeTable* CreatePrimeTable();
+
+template <>
+PrimeTable* CreatePrimeTable<OnTheFlyPrimeTable>() {
+  return new OnTheFlyPrimeTable;
+}
+
+template <>
+PrimeTable* CreatePrimeTable<PreCalculatedPrimeTable>() {
+  return new PreCalculatedPrimeTable(10000);
+}
+
+// Then we define a test fixture class template.
+template <class T>
+class PrimeTableTest : public testing::Test {
+ protected:
+  // The ctor calls the factory function to create a prime table
+  // implemented by T.
+  PrimeTableTest() : table_(CreatePrimeTable<T>()) {}
+
+  virtual ~PrimeTableTest() { delete table_; }
+
+  // Note that we test an implementation via the base interface
+  // instead of the actual implementation class.  This is important
+  // for keeping the tests close to the real world scenario, where the
+  // implementation is invoked via the base interface.  It avoids
+  // got-yas where the implementation class has a method that shadows
+  // a method with the same name (but slightly different argument
+  // types) in the base interface, for example.
+  PrimeTable* const table_;
+};
+
+#if GTEST_HAS_TYPED_TEST
+
+using testing::Types;
+
+// Google Test offers two ways for reusing tests for different types.
+// The first is called "typed tests".  You should use it if you
+// already know *all* the types you are gonna exercise when you write
+// the tests.
+
+// To write a typed test case, first use
+//
+//   TYPED_TEST_CASE(TestCaseName, TypeList);
+//
+// to declare it and specify the type parameters.  As with TEST_F,
+// TestCaseName must match the test fixture name.
+
+// The list of types we want to test.
+typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable> Implementations;
+
+TYPED_TEST_CASE(PrimeTableTest, Implementations);
+
+// Then use TYPED_TEST(TestCaseName, TestName) to define a typed test,
+// similar to TEST_F.
+TYPED_TEST(PrimeTableTest, ReturnsFalseForNonPrimes) {
+  // Inside the test body, you can refer to the type parameter by
+  // TypeParam, and refer to the fixture class by TestFixture.  We
+  // don't need them in this example.
+
+  // Since we are in the template world, C++ requires explicitly
+  // writing 'this->' when referring to members of the fixture class.
+  // This is something you have to learn to live with.
+  EXPECT_FALSE(this->table_->IsPrime(-5));
+  EXPECT_FALSE(this->table_->IsPrime(0));
+  EXPECT_FALSE(this->table_->IsPrime(1));
+  EXPECT_FALSE(this->table_->IsPrime(4));
+  EXPECT_FALSE(this->table_->IsPrime(6));
+  EXPECT_FALSE(this->table_->IsPrime(100));
+}
+
+TYPED_TEST(PrimeTableTest, ReturnsTrueForPrimes) {
+  EXPECT_TRUE(this->table_->IsPrime(2));
+  EXPECT_TRUE(this->table_->IsPrime(3));
+  EXPECT_TRUE(this->table_->IsPrime(5));
+  EXPECT_TRUE(this->table_->IsPrime(7));
+  EXPECT_TRUE(this->table_->IsPrime(11));
+  EXPECT_TRUE(this->table_->IsPrime(131));
+}
+
+TYPED_TEST(PrimeTableTest, CanGetNextPrime) {
+  EXPECT_EQ(2, this->table_->GetNextPrime(0));
+  EXPECT_EQ(3, this->table_->GetNextPrime(2));
+  EXPECT_EQ(5, this->table_->GetNextPrime(3));
+  EXPECT_EQ(7, this->table_->GetNextPrime(5));
+  EXPECT_EQ(11, this->table_->GetNextPrime(7));
+  EXPECT_EQ(131, this->table_->GetNextPrime(128));
+}
+
+// That's it!  Google Test will repeat each TYPED_TEST for each type
+// in the type list specified in TYPED_TEST_CASE.  Sit back and be
+// happy that you don't have to define them multiple times.
+
+#endif  // GTEST_HAS_TYPED_TEST
+
+#if GTEST_HAS_TYPED_TEST_P
+
+using testing::Types;
+
+// Sometimes, however, you don't yet know all the types that you want
+// to test when you write the tests.  For example, if you are the
+// author of an interface and expect other people to implement it, you
+// might want to write a set of tests to make sure each implementation
+// conforms to some basic requirements, but you don't know what
+// implementations will be written in the future.
+//
+// How can you write the tests without committing to the type
+// parameters?  That's what "type-parameterized tests" can do for you.
+// It is a bit more involved than typed tests, but in return you get a
+// test pattern that can be reused in many contexts, which is a big
+// win.  Here's how you do it:
+
+// First, define a test fixture class template.  Here we just reuse
+// the PrimeTableTest fixture defined earlier:
+
+template <class T>
+class PrimeTableTest2 : public PrimeTableTest<T> {
+};
+
+// Then, declare the test case.  The argument is the name of the test
+// fixture, and also the name of the test case (as usual).  The _P
+// suffix is for "parameterized" or "pattern".
+TYPED_TEST_CASE_P(PrimeTableTest2);
+
+// Next, use TYPED_TEST_P(TestCaseName, TestName) to define a test,
+// similar to what you do with TEST_F.
+TYPED_TEST_P(PrimeTableTest2, ReturnsFalseForNonPrimes) {
+  EXPECT_FALSE(this->table_->IsPrime(-5));
+  EXPECT_FALSE(this->table_->IsPrime(0));
+  EXPECT_FALSE(this->table_->IsPrime(1));
+  EXPECT_FALSE(this->table_->IsPrime(4));
+  EXPECT_FALSE(this->table_->IsPrime(6));
+  EXPECT_FALSE(this->table_->IsPrime(100));
+}
+
+TYPED_TEST_P(PrimeTableTest2, ReturnsTrueForPrimes) {
+  EXPECT_TRUE(this->table_->IsPrime(2));
+  EXPECT_TRUE(this->table_->IsPrime(3));
+  EXPECT_TRUE(this->table_->IsPrime(5));
+  EXPECT_TRUE(this->table_->IsPrime(7));
+  EXPECT_TRUE(this->table_->IsPrime(11));
+  EXPECT_TRUE(this->table_->IsPrime(131));
+}
+
+TYPED_TEST_P(PrimeTableTest2, CanGetNextPrime) {
+  EXPECT_EQ(2, this->table_->GetNextPrime(0));
+  EXPECT_EQ(3, this->table_->GetNextPrime(2));
+  EXPECT_EQ(5, this->table_->GetNextPrime(3));
+  EXPECT_EQ(7, this->table_->GetNextPrime(5));
+  EXPECT_EQ(11, this->table_->GetNextPrime(7));
+  EXPECT_EQ(131, this->table_->GetNextPrime(128));
+}
+
+// Type-parameterized tests involve one extra step: you have to
+// enumerate the tests you defined:
+REGISTER_TYPED_TEST_CASE_P(
+    PrimeTableTest2,  // The first argument is the test case name.
+    // The rest of the arguments are the test names.
+    ReturnsFalseForNonPrimes, ReturnsTrueForPrimes, CanGetNextPrime);
+
+// At this point the test pattern is done.  However, you don't have
+// any real test yet as you haven't said which types you want to run
+// the tests with.
+
+// To turn the abstract test pattern into real tests, you instantiate
+// it with a list of types.  Usually the test pattern will be defined
+// in a .h file, and anyone can #include and instantiate it.  You can
+// even instantiate it more than once in the same program.  To tell
+// different instances apart, you give each of them a name, which will
+// become part of the test case name and can be used in test filters.
+
+// The list of types we want to test.  Note that it doesn't have to be
+// defined at the time we write the TYPED_TEST_P()s.
+typedef Types<OnTheFlyPrimeTable, PreCalculatedPrimeTable>
+    PrimeTableImplementations;
+INSTANTIATE_TYPED_TEST_CASE_P(OnTheFlyAndPreCalculated,    // Instance name
+                              PrimeTableTest2,             // Test case name
+                              PrimeTableImplementations);  // Type list
+
+#endif  // GTEST_HAS_TYPED_TEST_P