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29//
30// Author: wan@google.com (Zhanyong Wan)
31
32#include <gtest/internal/gtest-tuple.h>
33#include <utility>
34#include <gtest/gtest.h>
35
36namespace {
37
38using ::std::tr1::get;
39using ::std::tr1::make_tuple;
40using ::std::tr1::tuple;
41using ::std::tr1::tuple_element;
42using ::std::tr1::tuple_size;
43using ::testing::StaticAssertTypeEq;
44
45// Tests that tuple_element<K, tuple<T0, T1, ..., TN> >::type returns TK.
46TEST(tuple_element_Test, ReturnsElementType) {
47  StaticAssertTypeEq<int, tuple_element<0, tuple<int, char> >::type>();
48  StaticAssertTypeEq<int&, tuple_element<1, tuple<double, int&> >::type>();
49  StaticAssertTypeEq<bool, tuple_element<2, tuple<double, int, bool> >::type>();
50}
51
52// Tests that tuple_size<T>::value gives the number of fields in tuple
53// type T.
54TEST(tuple_size_Test, ReturnsNumberOfFields) {
55  EXPECT_EQ(0, +tuple_size<tuple<> >::value);
56  EXPECT_EQ(1, +tuple_size<tuple<void*> >::value);
57  EXPECT_EQ(1, +tuple_size<tuple<char> >::value);
58  EXPECT_EQ(1, +(tuple_size<tuple<tuple<int, double> > >::value));
59  EXPECT_EQ(2, +(tuple_size<tuple<int&, const char> >::value));
60  EXPECT_EQ(3, +(tuple_size<tuple<char*, void, const bool&> >::value));
61}
62
63// Tests comparing a tuple with itself.
64TEST(ComparisonTest, ComparesWithSelf) {
65  const tuple<int, char, bool> a(5, 'a', false);
66
67  EXPECT_TRUE(a == a);
68  EXPECT_FALSE(a != a);
69}
70
71// Tests comparing two tuples with the same value.
72TEST(ComparisonTest, ComparesEqualTuples) {
73  const tuple<int, bool> a(5, true), b(5, true);
74
75  EXPECT_TRUE(a == b);
76  EXPECT_FALSE(a != b);
77}
78
79// Tests comparing two different tuples that have no reference fields.
80TEST(ComparisonTest, ComparesUnequalTuplesWithoutReferenceFields) {
81  typedef tuple<const int, char> FooTuple;
82
83  const FooTuple a(0, 'x');
84  const FooTuple b(1, 'a');
85
86  EXPECT_TRUE(a != b);
87  EXPECT_FALSE(a == b);
88
89  const FooTuple c(1, 'b');
90
91  EXPECT_TRUE(b != c);
92  EXPECT_FALSE(b == c);
93}
94
95// Tests comparing two different tuples that have reference fields.
96TEST(ComparisonTest, ComparesUnequalTuplesWithReferenceFields) {
97  typedef tuple<int&, const char&> FooTuple;
98
99  int i = 5;
100  const char ch = 'a';
101  const FooTuple a(i, ch);
102
103  int j = 6;
104  const FooTuple b(j, ch);
105
106  EXPECT_TRUE(a != b);
107  EXPECT_FALSE(a == b);
108
109  j = 5;
110  const char ch2 = 'b';
111  const FooTuple c(j, ch2);
112
113  EXPECT_TRUE(b != c);
114  EXPECT_FALSE(b == c);
115}
116
117// Tests that a tuple field with a reference type is an alias of the
118// variable it's supposed to reference.
119TEST(ReferenceFieldTest, IsAliasOfReferencedVariable) {
120  int n = 0;
121  tuple<bool, int&> t(true, n);
122
123  n = 1;
124  EXPECT_EQ(n, get<1>(t))
125      << "Changing a underlying variable should update the reference field.";
126
127  // Makes sure that the implementation doesn't do anything funny with
128  // the & operator for the return type of get<>().
129  EXPECT_EQ(&n, &(get<1>(t)))
130      << "The address of a reference field should equal the address of "
131      << "the underlying variable.";
132
133  get<1>(t) = 2;
134  EXPECT_EQ(2, n)
135      << "Changing a reference field should update the underlying variable.";
136}
137
138// Tests tuple's default constructor.
139TEST(TupleConstructorTest, DefaultConstructor) {
140  // We are just testing that the following compiles.
141  tuple<> empty;
142  tuple<int> one_field;
143  tuple<double, char, bool*> three_fields;
144}
145
146// Tests constructing a tuple from its fields.
147TEST(TupleConstructorTest, ConstructsFromFields) {
148  int n = 1;
149  // Reference field.
150  tuple<int&> a(n);
151  EXPECT_EQ(&n, &(get<0>(a)));
152
153  // Non-reference fields.
154  tuple<int, char> b(5, 'a');
155  EXPECT_EQ(5, get<0>(b));
156  EXPECT_EQ('a', get<1>(b));
157
158  // Const reference field.
159  const int m = 2;
160  tuple<bool, const int&> c(true, m);
161  EXPECT_TRUE(get<0>(c));
162  EXPECT_EQ(&m, &(get<1>(c)));
163}
164
165// Tests tuple's copy constructor.
166TEST(TupleConstructorTest, CopyConstructor) {
167  tuple<double, bool> a(0.0, true);
168  tuple<double, bool> b(a);
169
170  EXPECT_DOUBLE_EQ(0.0, get<0>(b));
171  EXPECT_TRUE(get<1>(b));
172}
173
174// Tests constructing a tuple from another tuple that has a compatible
175// but different type.
176TEST(TupleConstructorTest, ConstructsFromDifferentTupleType) {
177  tuple<int, int, char> a(0, 1, 'a');
178  tuple<double, long, int> b(a);
179
180  EXPECT_DOUBLE_EQ(0.0, get<0>(b));
181  EXPECT_EQ(1, get<1>(b));
182  EXPECT_EQ('a', get<2>(b));
183}
184
185// Tests constructing a 2-tuple from an std::pair.
186TEST(TupleConstructorTest, ConstructsFromPair) {
187  ::std::pair<int, char> a(1, 'a');
188  tuple<int, char> b(a);
189  tuple<int, const char&> c(a);
190}
191
192// Tests assigning a tuple to another tuple with the same type.
193TEST(TupleAssignmentTest, AssignsToSameTupleType) {
194  const tuple<int, long> a(5, 7L);
195  tuple<int, long> b;
196  b = a;
197  EXPECT_EQ(5, get<0>(b));
198  EXPECT_EQ(7L, get<1>(b));
199}
200
201// Tests assigning a tuple to another tuple with a different but
202// compatible type.
203TEST(TupleAssignmentTest, AssignsToDifferentTupleType) {
204  const tuple<int, long, bool> a(1, 7L, true);
205  tuple<long, int, bool> b;
206  b = a;
207  EXPECT_EQ(1L, get<0>(b));
208  EXPECT_EQ(7, get<1>(b));
209  EXPECT_TRUE(get<2>(b));
210}
211
212// Tests assigning an std::pair to a 2-tuple.
213TEST(TupleAssignmentTest, AssignsFromPair) {
214  const ::std::pair<int, bool> a(5, true);
215  tuple<int, bool> b;
216  b = a;
217  EXPECT_EQ(5, get<0>(b));
218  EXPECT_TRUE(get<1>(b));
219
220  tuple<long, bool> c;
221  c = a;
222  EXPECT_EQ(5L, get<0>(c));
223  EXPECT_TRUE(get<1>(c));
224}
225
226// A fixture for testing big tuples.
227class BigTupleTest : public testing::Test {
228 protected:
229  typedef tuple<int, int, int, int, int, int, int, int, int, int> BigTuple;
230
231  BigTupleTest() :
232      a_(1, 0, 0, 0, 0, 0, 0, 0, 0, 2),
233      b_(1, 0, 0, 0, 0, 0, 0, 0, 0, 3) {}
234
235  BigTuple a_, b_;
236};
237
238// Tests constructing big tuples.
239TEST_F(BigTupleTest, Construction) {
240  BigTuple a;
241  BigTuple b(b_);
242}
243
244// Tests that get<N>(t) returns the N-th (0-based) field of tuple t.
245TEST_F(BigTupleTest, get) {
246  EXPECT_EQ(1, get<0>(a_));
247  EXPECT_EQ(2, get<9>(a_));
248
249  // Tests that get() works on a const tuple too.
250  const BigTuple a(a_);
251  EXPECT_EQ(1, get<0>(a));
252  EXPECT_EQ(2, get<9>(a));
253}
254
255// Tests comparing big tuples.
256TEST_F(BigTupleTest, Comparisons) {
257  EXPECT_TRUE(a_ == a_);
258  EXPECT_FALSE(a_ != a_);
259
260  EXPECT_TRUE(a_ != b_);
261  EXPECT_FALSE(a_ == b_);
262}
263
264TEST(MakeTupleTest, WorksForScalarTypes) {
265  tuple<bool, int> a;
266  a = make_tuple(true, 5);
267  EXPECT_TRUE(get<0>(a));
268  EXPECT_EQ(5, get<1>(a));
269
270  tuple<char, int, long> b;
271  b = make_tuple('a', 'b', 5);
272  EXPECT_EQ('a', get<0>(b));
273  EXPECT_EQ('b', get<1>(b));
274  EXPECT_EQ(5, get<2>(b));
275}
276
277TEST(MakeTupleTest, WorksForPointers) {
278  int a[] = { 1, 2, 3, 4 };
279  const char* const str = "hi";
280  int* const p = a;
281
282  tuple<const char*, int*> t;
283  t = make_tuple(str, p);
284  EXPECT_EQ(str, get<0>(t));
285  EXPECT_EQ(p, get<1>(t));
286}
287
288}  // namespace
289