summaryrefslogtreecommitdiff
path: root/absl/container/internal/compressed_tuple_test.cc
blob: 2b5ed4a4abc574ccfcb54ec7475f59eedf76abd5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
// Copyright 2018 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "absl/container/internal/compressed_tuple.h"

#include <string>

#include "gmock/gmock.h"
#include "gtest/gtest.h"

namespace absl {
inline namespace lts_2018_12_18 {
namespace container_internal {
namespace {

template <int>
struct Empty {};

template <typename T>
struct NotEmpty {
  T value;
};

template <typename T, typename U>
struct TwoValues {
  T value1;
  U value2;
};

TEST(CompressedTupleTest, Sizeof) {
  EXPECT_EQ(sizeof(int), sizeof(CompressedTuple<int>));
  EXPECT_EQ(sizeof(int), sizeof(CompressedTuple<int, Empty<0>>));
  EXPECT_EQ(sizeof(int), sizeof(CompressedTuple<int, Empty<0>, Empty<1>>));
  EXPECT_EQ(sizeof(int),
            sizeof(CompressedTuple<int, Empty<0>, Empty<1>, Empty<2>>));

  EXPECT_EQ(sizeof(TwoValues<int, double>),
            sizeof(CompressedTuple<int, NotEmpty<double>>));
  EXPECT_EQ(sizeof(TwoValues<int, double>),
            sizeof(CompressedTuple<int, Empty<0>, NotEmpty<double>>));
  EXPECT_EQ(sizeof(TwoValues<int, double>),
            sizeof(CompressedTuple<int, Empty<0>, NotEmpty<double>, Empty<1>>));
}

TEST(CompressedTupleTest, Access) {
  struct S {
    std::string x;
  };
  CompressedTuple<int, Empty<0>, S> x(7, {}, S{"ABC"});
  EXPECT_EQ(sizeof(x), sizeof(TwoValues<int, S>));
  EXPECT_EQ(7, x.get<0>());
  EXPECT_EQ("ABC", x.get<2>().x);
}

TEST(CompressedTupleTest, NonClasses) {
  CompressedTuple<int, const char*> x(7, "ABC");
  EXPECT_EQ(7, x.get<0>());
  EXPECT_STREQ("ABC", x.get<1>());
}

TEST(CompressedTupleTest, MixClassAndNonClass) {
  CompressedTuple<int, const char*, Empty<0>, NotEmpty<double>> x(7, "ABC", {},
                                                                  {1.25});
  struct Mock {
    int v;
    const char* p;
    double d;
  };
  EXPECT_EQ(sizeof(x), sizeof(Mock));
  EXPECT_EQ(7, x.get<0>());
  EXPECT_STREQ("ABC", x.get<1>());
  EXPECT_EQ(1.25, x.get<3>().value);
}

TEST(CompressedTupleTest, Nested) {
  CompressedTuple<int, CompressedTuple<int>,
                  CompressedTuple<int, CompressedTuple<int>>>
      x(1, CompressedTuple<int>(2),
        CompressedTuple<int, CompressedTuple<int>>(3, CompressedTuple<int>(4)));
  EXPECT_EQ(1, x.get<0>());
  EXPECT_EQ(2, x.get<1>().get<0>());
  EXPECT_EQ(3, x.get<2>().get<0>());
  EXPECT_EQ(4, x.get<2>().get<1>().get<0>());

  CompressedTuple<Empty<0>, Empty<0>,
                  CompressedTuple<Empty<0>, CompressedTuple<Empty<0>>>>
      y;
  std::set<Empty<0>*> empties{&y.get<0>(), &y.get<1>(), &y.get<2>().get<0>(),
                              &y.get<2>().get<1>().get<0>()};
#ifdef _MSC_VER
  // MSVC has a bug where many instances of the same base class are layed out in
  // the same address when using __declspec(empty_bases).
  // This will be fixed in a future version of MSVC.
  int expected = 1;
#else
  int expected = 4;
#endif
  EXPECT_EQ(expected, sizeof(y));
  EXPECT_EQ(expected, empties.size());
  EXPECT_EQ(sizeof(y), sizeof(Empty<0>) * empties.size());

  EXPECT_EQ(4 * sizeof(char),
            sizeof(CompressedTuple<CompressedTuple<char, char>,
                                   CompressedTuple<char, char>>));
  EXPECT_TRUE(
      (std::is_empty<CompressedTuple<CompressedTuple<Empty<0>>,
                                     CompressedTuple<Empty<1>>>>::value));
}

TEST(CompressedTupleTest, Reference) {
  int i = 7;
  std::string s = "Very long std::string that goes in the heap";
  CompressedTuple<int, int&, std::string, std::string&> x(i, i, s, s);

  // Sanity check. We should have not moved from `s`
  EXPECT_EQ(s, "Very long std::string that goes in the heap");

  EXPECT_EQ(x.get<0>(), x.get<1>());
  EXPECT_NE(&x.get<0>(), &x.get<1>());
  EXPECT_EQ(&x.get<1>(), &i);

  EXPECT_EQ(x.get<2>(), x.get<3>());
  EXPECT_NE(&x.get<2>(), &x.get<3>());
  EXPECT_EQ(&x.get<3>(), &s);
}

TEST(CompressedTupleTest, NoElements) {
  CompressedTuple<> x;
  static_cast<void>(x);  // Silence -Wunused-variable.
  EXPECT_TRUE(std::is_empty<CompressedTuple<>>::value);
}

TEST(CompressedTupleTest, Constexpr) {
  constexpr CompressedTuple<int, double, CompressedTuple<int>> x(
      7, 1.25, CompressedTuple<int>(5));
  constexpr int x0 = x.get<0>();
  constexpr double x1 = x.get<1>();
  constexpr int x2 = x.get<2>().get<0>();
  EXPECT_EQ(x0, 7);
  EXPECT_EQ(x1, 1.25);
  EXPECT_EQ(x2, 5);
}

#if defined(__clang__) || defined(__GNUC__)
TEST(CompressedTupleTest, EmptyFinalClass) {
  struct S final {
    int f() const { return 5; }
  };
  CompressedTuple<S> x;
  EXPECT_EQ(x.get<0>().f(), 5);
}
#endif

}  // namespace
}  // namespace container_internal
}  // inline namespace lts_2018_12_18
}  // namespace absl