llvm.org GIT mirror llvm / release_50 unittests / ADT / DenseMapTest.cpp
release_50

Tree @release_50 (Download .tar.gz)

DenseMapTest.cpp @release_50raw · history · blame

  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
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
//===- llvm/unittest/ADT/DenseMapMap.cpp - DenseMap unit tests --*- C++ -*-===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#include "llvm/ADT/DenseMap.h"
#include "gtest/gtest.h"
#include <map>
#include <set>

using namespace llvm;

namespace {

uint32_t getTestKey(int i, uint32_t *) { return i; }
uint32_t getTestValue(int i, uint32_t *) { return 42 + i; }

uint32_t *getTestKey(int i, uint32_t **) {
  static uint32_t dummy_arr1[8192];
  assert(i < 8192 && "Only support 8192 dummy keys.");
  return &dummy_arr1[i];
}
uint32_t *getTestValue(int i, uint32_t **) {
  static uint32_t dummy_arr1[8192];
  assert(i < 8192 && "Only support 8192 dummy keys.");
  return &dummy_arr1[i];
}

/// \brief A test class that tries to check that construction and destruction
/// occur correctly.
class CtorTester {
  static std::set<CtorTester *> Constructed;
  int Value;

public:
  explicit CtorTester(int Value = 0) : Value(Value) {
    EXPECT_TRUE(Constructed.insert(this).second);
  }
  CtorTester(uint32_t Value) : Value(Value) {
    EXPECT_TRUE(Constructed.insert(this).second);
  }
  CtorTester(const CtorTester &Arg) : Value(Arg.Value) {
    EXPECT_TRUE(Constructed.insert(this).second);
  }
  CtorTester &operator=(const CtorTester &) = default;
  ~CtorTester() {
    EXPECT_EQ(1u, Constructed.erase(this));
  }
  operator uint32_t() const { return Value; }

  int getValue() const { return Value; }
  bool operator==(const CtorTester &RHS) const { return Value == RHS.Value; }
};

std::set<CtorTester *> CtorTester::Constructed;

struct CtorTesterMapInfo {
  static inline CtorTester getEmptyKey() { return CtorTester(-1); }
  static inline CtorTester getTombstoneKey() { return CtorTester(-2); }
  static unsigned getHashValue(const CtorTester &Val) {
    return Val.getValue() * 37u;
  }
  static bool isEqual(const CtorTester &LHS, const CtorTester &RHS) {
    return LHS == RHS;
  }
};

CtorTester getTestKey(int i, CtorTester *) { return CtorTester(i); }
CtorTester getTestValue(int i, CtorTester *) { return CtorTester(42 + i); }

// Test fixture, with helper functions implemented by forwarding to global
// function overloads selected by component types of the type parameter. This
// allows all of the map implementations to be tested with shared
// implementations of helper routines.
template <typename T>
class DenseMapTest : public ::testing::Test {
protected:
  T Map;

  static typename T::key_type *const dummy_key_ptr;
  static typename T::mapped_type *const dummy_value_ptr;

  typename T::key_type getKey(int i = 0) {
    return getTestKey(i, dummy_key_ptr);
  }
  typename T::mapped_type getValue(int i = 0) {
    return getTestValue(i, dummy_value_ptr);
  }
};

template <typename T>
typename T::key_type *const DenseMapTest<T>::dummy_key_ptr = nullptr;
template <typename T>
typename T::mapped_type *const DenseMapTest<T>::dummy_value_ptr = nullptr;

// Register these types for testing.
typedef ::testing::Types<DenseMap<uint32_t, uint32_t>,
                         DenseMap<uint32_t *, uint32_t *>,
                         DenseMap<CtorTester, CtorTester, CtorTesterMapInfo>,
                         SmallDenseMap<uint32_t, uint32_t>,
                         SmallDenseMap<uint32_t *, uint32_t *>,
                         SmallDenseMap<CtorTester, CtorTester, 4,
                                       CtorTesterMapInfo>
                         > DenseMapTestTypes;
TYPED_TEST_CASE(DenseMapTest, DenseMapTestTypes);

// Empty map tests
TYPED_TEST(DenseMapTest, EmptyIntMapTest) {
  // Size tests
  EXPECT_EQ(0u, this->Map.size());
  EXPECT_TRUE(this->Map.empty());

  // Iterator tests
  EXPECT_TRUE(this->Map.begin() == this->Map.end());

  // Lookup tests
  EXPECT_FALSE(this->Map.count(this->getKey()));
  EXPECT_TRUE(this->Map.find(this->getKey()) == this->Map.end());
#if !defined(_MSC_VER) || defined(__clang__)
  EXPECT_EQ(typename TypeParam::mapped_type(),
            this->Map.lookup(this->getKey()));
#else
  // MSVC, at least old versions, cannot parse the typename to disambiguate
  // TypeParam::mapped_type as a type. However, because MSVC doesn't implement
  // two-phase name lookup, it also doesn't require the typename. Deal with
  // this mutual incompatibility through specialized code.
  EXPECT_EQ(TypeParam::mapped_type(),
            this->Map.lookup(this->getKey()));
#endif
}

// Constant map tests
TYPED_TEST(DenseMapTest, ConstEmptyMapTest) {
  const TypeParam &ConstMap = this->Map;
  EXPECT_EQ(0u, ConstMap.size());
  EXPECT_TRUE(ConstMap.empty());
  EXPECT_TRUE(ConstMap.begin() == ConstMap.end());
}

// A map with a single entry
TYPED_TEST(DenseMapTest, SingleEntryMapTest) {
  this->Map[this->getKey()] = this->getValue();

  // Size tests
  EXPECT_EQ(1u, this->Map.size());
  EXPECT_FALSE(this->Map.begin() == this->Map.end());
  EXPECT_FALSE(this->Map.empty());

  // Iterator tests
  typename TypeParam::iterator it = this->Map.begin();
  EXPECT_EQ(this->getKey(), it->first);
  EXPECT_EQ(this->getValue(), it->second);
  ++it;
  EXPECT_TRUE(it == this->Map.end());

  // Lookup tests
  EXPECT_TRUE(this->Map.count(this->getKey()));
  EXPECT_TRUE(this->Map.find(this->getKey()) == this->Map.begin());
  EXPECT_EQ(this->getValue(), this->Map.lookup(this->getKey()));
  EXPECT_EQ(this->getValue(), this->Map[this->getKey()]);
}

// Test clear() method
TYPED_TEST(DenseMapTest, ClearTest) {
  this->Map[this->getKey()] = this->getValue();
  this->Map.clear();

  EXPECT_EQ(0u, this->Map.size());
  EXPECT_TRUE(this->Map.empty());
  EXPECT_TRUE(this->Map.begin() == this->Map.end());
}

// Test erase(iterator) method
TYPED_TEST(DenseMapTest, EraseTest) {
  this->Map[this->getKey()] = this->getValue();
  this->Map.erase(this->Map.begin());

  EXPECT_EQ(0u, this->Map.size());
  EXPECT_TRUE(this->Map.empty());
  EXPECT_TRUE(this->Map.begin() == this->Map.end());
}

// Test erase(value) method
TYPED_TEST(DenseMapTest, EraseTest2) {
  this->Map[this->getKey()] = this->getValue();
  this->Map.erase(this->getKey());

  EXPECT_EQ(0u, this->Map.size());
  EXPECT_TRUE(this->Map.empty());
  EXPECT_TRUE(this->Map.begin() == this->Map.end());
}

// Test insert() method
TYPED_TEST(DenseMapTest, InsertTest) {
  this->Map.insert(std::make_pair(this->getKey(), this->getValue()));
  EXPECT_EQ(1u, this->Map.size());
  EXPECT_EQ(this->getValue(), this->Map[this->getKey()]);
}

// Test copy constructor method
TYPED_TEST(DenseMapTest, CopyConstructorTest) {
  this->Map[this->getKey()] = this->getValue();
  TypeParam copyMap(this->Map);

  EXPECT_EQ(1u, copyMap.size());
  EXPECT_EQ(this->getValue(), copyMap[this->getKey()]);
}

// Test copy constructor method where SmallDenseMap isn't small.
TYPED_TEST(DenseMapTest, CopyConstructorNotSmallTest) {
  for (int Key = 0; Key < 5; ++Key)
    this->Map[this->getKey(Key)] = this->getValue(Key);
  TypeParam copyMap(this->Map);

  EXPECT_EQ(5u, copyMap.size());
  for (int Key = 0; Key < 5; ++Key)
    EXPECT_EQ(this->getValue(Key), copyMap[this->getKey(Key)]);
}

// Test copying from a default-constructed map.
TYPED_TEST(DenseMapTest, CopyConstructorFromDefaultTest) {
  TypeParam copyMap(this->Map);

  EXPECT_TRUE(copyMap.empty());
}

// Test copying from an empty map where SmallDenseMap isn't small.
TYPED_TEST(DenseMapTest, CopyConstructorFromEmptyTest) {
  for (int Key = 0; Key < 5; ++Key)
    this->Map[this->getKey(Key)] = this->getValue(Key);
  this->Map.clear();
  TypeParam copyMap(this->Map);

  EXPECT_TRUE(copyMap.empty());
}

// Test assignment operator method
TYPED_TEST(DenseMapTest, AssignmentTest) {
  this->Map[this->getKey()] = this->getValue();
  TypeParam copyMap = this->Map;

  EXPECT_EQ(1u, copyMap.size());
  EXPECT_EQ(this->getValue(), copyMap[this->getKey()]);

  // test self-assignment.
  copyMap = copyMap;
  EXPECT_EQ(1u, copyMap.size());
  EXPECT_EQ(this->getValue(), copyMap[this->getKey()]);
}

TYPED_TEST(DenseMapTest, AssignmentTestNotSmall) {
  for (int Key = 0; Key < 5; ++Key)
    this->Map[this->getKey(Key)] = this->getValue(Key);
  TypeParam copyMap = this->Map;

  EXPECT_EQ(5u, copyMap.size());
  for (int Key = 0; Key < 5; ++Key)
    EXPECT_EQ(this->getValue(Key), copyMap[this->getKey(Key)]);

  // test self-assignment.
  copyMap = copyMap;
  EXPECT_EQ(5u, copyMap.size());
  for (int Key = 0; Key < 5; ++Key)
    EXPECT_EQ(this->getValue(Key), copyMap[this->getKey(Key)]);
}

// Test swap method
TYPED_TEST(DenseMapTest, SwapTest) {
  this->Map[this->getKey()] = this->getValue();
  TypeParam otherMap;

  this->Map.swap(otherMap);
  EXPECT_EQ(0u, this->Map.size());
  EXPECT_TRUE(this->Map.empty());
  EXPECT_EQ(1u, otherMap.size());
  EXPECT_EQ(this->getValue(), otherMap[this->getKey()]);

  this->Map.swap(otherMap);
  EXPECT_EQ(0u, otherMap.size());
  EXPECT_TRUE(otherMap.empty());
  EXPECT_EQ(1u, this->Map.size());
  EXPECT_EQ(this->getValue(), this->Map[this->getKey()]);

  // Make this more interesting by inserting 100 numbers into the map.
  for (int i = 0; i < 100; ++i)
    this->Map[this->getKey(i)] = this->getValue(i);

  this->Map.swap(otherMap);
  EXPECT_EQ(0u, this->Map.size());
  EXPECT_TRUE(this->Map.empty());
  EXPECT_EQ(100u, otherMap.size());
  for (int i = 0; i < 100; ++i)
    EXPECT_EQ(this->getValue(i), otherMap[this->getKey(i)]);

  this->Map.swap(otherMap);
  EXPECT_EQ(0u, otherMap.size());
  EXPECT_TRUE(otherMap.empty());
  EXPECT_EQ(100u, this->Map.size());
  for (int i = 0; i < 100; ++i)
    EXPECT_EQ(this->getValue(i), this->Map[this->getKey(i)]);
}

// A more complex iteration test
TYPED_TEST(DenseMapTest, IterationTest) {
  bool visited[100];
  std::map<typename TypeParam::key_type, unsigned> visitedIndex;

  // Insert 100 numbers into the map
  for (int i = 0; i < 100; ++i) {
    visited[i] = false;
    visitedIndex[this->getKey(i)] = i;

    this->Map[this->getKey(i)] = this->getValue(i);
  }

  // Iterate over all numbers and mark each one found.
  for (typename TypeParam::iterator it = this->Map.begin();
       it != this->Map.end(); ++it)
    visited[visitedIndex[it->first]] = true;

  // Ensure every number was visited.
  for (int i = 0; i < 100; ++i)
    ASSERT_TRUE(visited[i]) << "Entry #" << i << " was never visited";
}

// const_iterator test
TYPED_TEST(DenseMapTest, ConstIteratorTest) {
  // Check conversion from iterator to const_iterator.
  typename TypeParam::iterator it = this->Map.begin();
  typename TypeParam::const_iterator cit(it);
  EXPECT_TRUE(it == cit);

  // Check copying of const_iterators.
  typename TypeParam::const_iterator cit2(cit);
  EXPECT_TRUE(cit == cit2);
}

namespace {
// Simple class that counts how many moves and copy happens when growing a map
struct CountCopyAndMove {
  static int Move;
  static int Copy;
  CountCopyAndMove() {}

  CountCopyAndMove(const CountCopyAndMove &) { Copy++; }
  CountCopyAndMove &operator=(const CountCopyAndMove &) {
    Copy++;
    return *this;
  }
  CountCopyAndMove(CountCopyAndMove &&) { Move++; }
  CountCopyAndMove &operator=(const CountCopyAndMove &&) {
    Move++;
    return *this;
  }
};
int CountCopyAndMove::Copy = 0;
int CountCopyAndMove::Move = 0;

} // anonymous namespace

// Test for the default minimum size of a DenseMap
TEST(DenseMapCustomTest, DefaultMinReservedSizeTest) {
  // IF THIS VALUE CHANGE, please update InitialSizeTest, InitFromIterator, and
  // ReserveTest as well!
  const int ExpectedInitialBucketCount = 64;
  // Formula from DenseMap::getMinBucketToReserveForEntries()
  const int ExpectedMaxInitialEntries = ExpectedInitialBucketCount * 3 / 4 - 1;

  DenseMap<int, CountCopyAndMove> Map;
  // Will allocate 64 buckets
  Map.reserve(1);
  unsigned MemorySize = Map.getMemorySize();
  CountCopyAndMove::Copy = 0;
  CountCopyAndMove::Move = 0;
  for (int i = 0; i < ExpectedMaxInitialEntries; ++i)
    Map.insert(std::pair<int, CountCopyAndMove>(std::piecewise_construct,
                                                std::forward_as_tuple(i),
                                                std::forward_as_tuple()));
  // Check that we didn't grow
  EXPECT_EQ(MemorySize, Map.getMemorySize());
  // Check that move was called the expected number of times
  EXPECT_EQ(ExpectedMaxInitialEntries, CountCopyAndMove::Move);
  // Check that no copy occured
  EXPECT_EQ(0, CountCopyAndMove::Copy);

  // Adding one extra element should grow the map
  Map.insert(std::pair<int, CountCopyAndMove>(
      std::piecewise_construct,
      std::forward_as_tuple(ExpectedMaxInitialEntries),
      std::forward_as_tuple()));
  // Check that we grew
  EXPECT_NE(MemorySize, Map.getMemorySize());
  // Check that move was called the expected number of times
  //  This relies on move-construction elision, and cannot be reliably tested.
  //   EXPECT_EQ(ExpectedMaxInitialEntries + 2, CountCopyAndMove::Move);
  // Check that no copy occured
  EXPECT_EQ(0, CountCopyAndMove::Copy);
}

// Make sure creating the map with an initial size of N actually gives us enough
// buckets to insert N items without increasing allocation size.
TEST(DenseMapCustomTest, InitialSizeTest) {
  // Test a few different sizes, 48 is *not* a random choice: we need a value
  // that is 2/3 of a power of two to stress the grow() condition, and the power
  // of two has to be at least 64 because of minimum size allocation in the
  // DenseMap (see DefaultMinReservedSizeTest). 66 is a value just above the
  // 64 default init.
  for (auto Size : {1, 2, 48, 66}) {
    DenseMap<int, CountCopyAndMove> Map(Size);
    unsigned MemorySize = Map.getMemorySize();
    CountCopyAndMove::Copy = 0;
    CountCopyAndMove::Move = 0;
    for (int i = 0; i < Size; ++i)
      Map.insert(std::pair<int, CountCopyAndMove>(std::piecewise_construct,
                                                  std::forward_as_tuple(i),
                                                  std::forward_as_tuple()));
    // Check that we didn't grow
    EXPECT_EQ(MemorySize, Map.getMemorySize());
    // Check that move was called the expected number of times
    EXPECT_EQ(Size, CountCopyAndMove::Move);
    // Check that no copy occured
    EXPECT_EQ(0, CountCopyAndMove::Copy);
  }
}

// Make sure creating the map with a iterator range does not trigger grow()
TEST(DenseMapCustomTest, InitFromIterator) {
  std::vector<std::pair<int, CountCopyAndMove>> Values;
  // The size is a random value greater than 64 (hardcoded DenseMap min init)
  const int Count = 65;
  for (int i = 0; i < Count; i++)
    Values.emplace_back(i, CountCopyAndMove());

  CountCopyAndMove::Move = 0;
  CountCopyAndMove::Copy = 0;
  DenseMap<int, CountCopyAndMove> Map(Values.begin(), Values.end());
  // Check that no move occured
  EXPECT_EQ(0, CountCopyAndMove::Move);
  // Check that copy was called the expected number of times
  EXPECT_EQ(Count, CountCopyAndMove::Copy);
}

// Make sure reserve actually gives us enough buckets to insert N items
// without increasing allocation size.
TEST(DenseMapCustomTest, ReserveTest) {
  // Test a few different size, 48 is *not* a random choice: we need a value
  // that is 2/3 of a power of two to stress the grow() condition, and the power
  // of two has to be at least 64 because of minimum size allocation in the
  // DenseMap (see DefaultMinReservedSizeTest). 66 is a value just above the
  // 64 default init.
  for (auto Size : {1, 2, 48, 66}) {
    DenseMap<int, CountCopyAndMove> Map;
    Map.reserve(Size);
    unsigned MemorySize = Map.getMemorySize();
    CountCopyAndMove::Copy = 0;
    CountCopyAndMove::Move = 0;
    for (int i = 0; i < Size; ++i)
      Map.insert(std::pair<int, CountCopyAndMove>(std::piecewise_construct,
                                                  std::forward_as_tuple(i),
                                                  std::forward_as_tuple()));
    // Check that we didn't grow
    EXPECT_EQ(MemorySize, Map.getMemorySize());
    // Check that move was called the expected number of times
    EXPECT_EQ(Size, CountCopyAndMove::Move);
    // Check that no copy occured
    EXPECT_EQ(0, CountCopyAndMove::Copy);
  }
}

// Make sure DenseMap works with StringRef keys.
TEST(DenseMapCustomTest, StringRefTest) {
  DenseMap<StringRef, int> M;

  M["a"] = 1;
  M["b"] = 2;
  M["c"] = 3;

  EXPECT_EQ(3u, M.size());
  EXPECT_EQ(1, M.lookup("a"));
  EXPECT_EQ(2, M.lookup("b"));
  EXPECT_EQ(3, M.lookup("c"));

  EXPECT_EQ(0, M.lookup("q"));

  // Test the empty string, spelled various ways.
  EXPECT_EQ(0, M.lookup(""));
  EXPECT_EQ(0, M.lookup(StringRef()));
  EXPECT_EQ(0, M.lookup(StringRef("a", 0)));
  M[""] = 42;
  EXPECT_EQ(42, M.lookup(""));
  EXPECT_EQ(42, M.lookup(StringRef()));
  EXPECT_EQ(42, M.lookup(StringRef("a", 0)));
}

// Key traits that allows lookup with either an unsigned or char* key;
// In the latter case, "a" == 0, "b" == 1 and so on.
struct TestDenseMapInfo {
  static inline unsigned getEmptyKey() { return ~0; }
  static inline unsigned getTombstoneKey() { return ~0U - 1; }
  static unsigned getHashValue(const unsigned& Val) { return Val * 37U; }
  static unsigned getHashValue(const char* Val) {
    return (unsigned)(Val[0] - 'a') * 37U;
  }
  static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
    return LHS == RHS;
  }
  static bool isEqual(const char* LHS, const unsigned& RHS) {
    return (unsigned)(LHS[0] - 'a') == RHS;
  }
};

// find_as() tests
TEST(DenseMapCustomTest, FindAsTest) {
  DenseMap<unsigned, unsigned, TestDenseMapInfo> map;
  map[0] = 1;
  map[1] = 2;
  map[2] = 3;

  // Size tests
  EXPECT_EQ(3u, map.size());

  // Normal lookup tests
  EXPECT_EQ(1u, map.count(1));
  EXPECT_EQ(1u, map.find(0)->second);
  EXPECT_EQ(2u, map.find(1)->second);
  EXPECT_EQ(3u, map.find(2)->second);
  EXPECT_TRUE(map.find(3) == map.end());

  // find_as() tests
  EXPECT_EQ(1u, map.find_as("a")->second);
  EXPECT_EQ(2u, map.find_as("b")->second);
  EXPECT_EQ(3u, map.find_as("c")->second);
  EXPECT_TRUE(map.find_as("d") == map.end());
}

struct ContiguousDenseMapInfo {
  static inline unsigned getEmptyKey() { return ~0; }
  static inline unsigned getTombstoneKey() { return ~0U - 1; }
  static unsigned getHashValue(const unsigned& Val) { return Val; }
  static bool isEqual(const unsigned& LHS, const unsigned& RHS) {
    return LHS == RHS;
  }
};

// Test that filling a small dense map with exactly the number of elements in
// the map grows to have enough space for an empty bucket.
TEST(DenseMapCustomTest, SmallDenseMapGrowTest) {
  SmallDenseMap<unsigned, unsigned, 32, ContiguousDenseMapInfo> map;
  // Add some number of elements, then delete a few to leave us some tombstones.
  // If we just filled the map with 32 elements we'd grow because of not enough
  // tombstones which masks the issue here.
  for (unsigned i = 0; i < 20; ++i)
    map[i] = i + 1;
  for (unsigned i = 0; i < 10; ++i)
    map.erase(i);
  for (unsigned i = 20; i < 32; ++i)
    map[i] = i + 1;

  // Size tests
  EXPECT_EQ(22u, map.size());

  // Try to find an element which doesn't exist.  There was a bug in
  // SmallDenseMap which led to a map with num elements == small capacity not
  // having an empty bucket any more.  Finding an element not in the map would
  // therefore never terminate.
  EXPECT_TRUE(map.find(32) == map.end());
}

TEST(DenseMapCustomTest, TryEmplaceTest) {
  DenseMap<int, std::unique_ptr<int>> Map;
  std::unique_ptr<int> P(new int(2));
  auto Try1 = Map.try_emplace(0, new int(1));
  EXPECT_TRUE(Try1.second);
  auto Try2 = Map.try_emplace(0, std::move(P));
  EXPECT_FALSE(Try2.second);
  EXPECT_EQ(Try1.first, Try2.first);
  EXPECT_NE(nullptr, P);
}

TEST(DenseMapCustomTest, ConstTest) {
  // Test that const pointers work okay for count and find, even when the
  // underlying map is a non-const pointer.
  DenseMap<int *, int> Map;
  int A;
  int *B = &A;
  const int *C = &A;
  Map.insert({B, 0});
  EXPECT_EQ(Map.count(B), 1u);
  EXPECT_EQ(Map.count(C), 1u);
  EXPECT_NE(Map.find(B), Map.end());
  EXPECT_NE(Map.find(C), Map.end());
}
}