2 * Copyright 2017 Facebook, Inc.
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
8 * http://www.apache.org/licenses/LICENSE-2.0
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
17 #include <folly/Optional.h>
18 #include <folly/Portability.h>
19 #include <folly/portability/GTest.h>
25 #include <type_traits>
26 #include <unordered_map>
29 #include <boost/optional.hpp>
31 using std::unique_ptr;
32 using std::shared_ptr;
37 std::ostream& operator<<(std::ostream& os, const Optional<V>& v) {
39 os << "Optional(" << v.value() << ')';
47 NoDefault(int, int) {}
51 static_assert(sizeof(Optional<char>) == 2, "");
52 static_assert(sizeof(Optional<int>) == 8, "");
53 static_assert(sizeof(Optional<NoDefault>) == 4, "");
54 static_assert(sizeof(Optional<char>) == sizeof(boost::optional<char>), "");
55 static_assert(sizeof(Optional<short>) == sizeof(boost::optional<short>), "");
56 static_assert(sizeof(Optional<int>) == sizeof(boost::optional<int>), "");
57 static_assert(sizeof(Optional<double>) == sizeof(boost::optional<double>), "");
59 TEST(Optional, NoDefault) {
60 Optional<NoDefault> x;
68 TEST(Optional, String) {
69 Optional<std::string> maybeString;
70 EXPECT_FALSE(maybeString);
71 maybeString = "hello";
72 EXPECT_TRUE(bool(maybeString));
75 TEST(Optional, Const) {
76 { // default construct
77 Optional<const int> opt;
78 EXPECT_FALSE(bool(opt));
84 EXPECT_FALSE(bool(opt));
88 Optional<const int> opt(x);
93 Optional<const int> opt(std::move(x));
96 // no assignment allowed
99 TEST(Optional, Simple) {
101 EXPECT_FALSE(bool(opt));
102 EXPECT_EQ(42, opt.value_or(42));
104 EXPECT_TRUE(bool(opt));
106 EXPECT_EQ(4, opt.value_or(42));
110 EXPECT_FALSE(bool(opt));
115 /* implicit */ MoveTester(const char* s) : s_(s) {}
116 MoveTester(const MoveTester&) = default;
117 MoveTester(MoveTester&& other) noexcept {
118 s_ = std::move(other.s_);
121 MoveTester& operator=(const MoveTester&) = default;
122 MoveTester& operator=(MoveTester&& other) noexcept {
123 s_ = std::move(other.s_);
128 friend bool operator==(const MoveTester& o1, const MoveTester& o2);
132 bool operator==(const MoveTester& o1, const MoveTester& o2) {
133 return o1.s_ == o2.s_;
136 TEST(Optional, value_or_rvalue_arg) {
137 Optional<MoveTester> opt;
138 MoveTester dflt = "hello";
139 EXPECT_EQ("hello", opt.value_or(dflt));
140 EXPECT_EQ("hello", dflt);
141 EXPECT_EQ("hello", opt.value_or(std::move(dflt)));
143 EXPECT_EQ("world", opt.value_or("world"));
146 // Make sure that the const overload works on const objects
147 const auto& optc = opt;
148 EXPECT_EQ("hello", optc.value_or(dflt));
149 EXPECT_EQ("hello", dflt);
150 EXPECT_EQ("hello", optc.value_or(std::move(dflt)));
152 EXPECT_EQ("world", optc.value_or("world"));
156 EXPECT_EQ("meow", opt.value_or(dflt));
157 EXPECT_EQ("hello", dflt);
158 EXPECT_EQ("meow", opt.value_or(std::move(dflt)));
159 EXPECT_EQ("hello", dflt); // only moved if used
162 TEST(Optional, value_or_noncopyable) {
163 Optional<std::unique_ptr<int>> opt;
164 std::unique_ptr<int> dflt(new int(42));
165 EXPECT_EQ(42, *std::move(opt).value_or(std::move(dflt)));
168 struct ExpectingDeleter {
169 explicit ExpectingDeleter(int expected) : expected(expected) { }
171 void operator()(const int* ptr) {
172 EXPECT_EQ(*ptr, expected);
177 TEST(Optional, value_move) {
178 auto ptr = Optional<std::unique_ptr<int, ExpectingDeleter>>(
179 {new int(42), ExpectingDeleter{1337}}).value();
183 TEST(Optional, dereference_move) {
184 auto ptr = *Optional<std::unique_ptr<int, ExpectingDeleter>>(
185 {new int(42), ExpectingDeleter{1337}});
189 TEST(Optional, EmptyConstruct) {
191 EXPECT_FALSE(bool(opt));
192 Optional<int> test1(opt);
193 EXPECT_FALSE(bool(test1));
194 Optional<int> test2(std::move(opt));
195 EXPECT_FALSE(bool(test2));
198 TEST(Optional, Unique) {
199 Optional<unique_ptr<int>> opt;
202 EXPECT_FALSE(bool(opt));
204 opt.emplace(new int(5));
205 EXPECT_TRUE(bool(opt));
210 opt = unique_ptr<int>(new int(6));
213 opt = unique_ptr<int>(new int(7));
216 // move it out by move construct
217 Optional<unique_ptr<int>> moved(std::move(opt));
218 EXPECT_TRUE(bool(moved));
219 EXPECT_FALSE(bool(opt));
220 EXPECT_EQ(7, **moved);
222 EXPECT_TRUE(bool(moved));
223 opt = std::move(moved); // move it back by move assign
224 EXPECT_FALSE(bool(moved));
225 EXPECT_TRUE(bool(opt));
229 TEST(Optional, Shared) {
231 Optional<shared_ptr<int>> opt;
232 EXPECT_FALSE(bool(opt));
234 opt.emplace(new int(5));
235 EXPECT_TRUE(bool(opt));
237 EXPECT_EQ(ptr.get(), opt->get());
238 EXPECT_EQ(2, ptr.use_count());
240 EXPECT_EQ(1, ptr.use_count());
243 EXPECT_EQ(2, ptr.use_count());
244 EXPECT_EQ(ptr.get(), opt->get());
246 EXPECT_EQ(1, ptr.use_count());
248 opt = std::move(ptr);
249 EXPECT_EQ(1, opt->use_count());
250 EXPECT_EQ(nullptr, ptr.get());
252 Optional<shared_ptr<int>> copied(opt);
253 EXPECT_EQ(2, opt->use_count());
254 Optional<shared_ptr<int>> moved(std::move(opt));
255 EXPECT_EQ(2, moved->use_count());
256 moved.emplace(new int(6));
257 EXPECT_EQ(1, moved->use_count());
259 EXPECT_EQ(2, moved->use_count());
263 TEST(Optional, Order) {
264 std::vector<Optional<int>> vect{
271 std::vector<Optional<int>> expected {
278 std::sort(vect.begin(), vect.end());
279 EXPECT_EQ(vect, expected);
282 TEST(Optional, Swap) {
283 Optional<std::string> a;
284 Optional<std::string> b;
287 EXPECT_FALSE(a.hasValue());
288 EXPECT_FALSE(b.hasValue());
291 EXPECT_TRUE(a.hasValue());
292 EXPECT_FALSE(b.hasValue());
293 EXPECT_EQ("hello", a.value());
296 EXPECT_FALSE(a.hasValue());
297 EXPECT_TRUE(b.hasValue());
298 EXPECT_EQ("hello", b.value());
301 EXPECT_TRUE(a.hasValue());
302 EXPECT_EQ("bye", a.value());
307 TEST(Optional, Comparisons) {
312 EXPECT_TRUE(o_ <= (o_));
313 EXPECT_TRUE(o_ == (o_));
314 EXPECT_TRUE(o_ >= (o_));
316 EXPECT_TRUE(o1 < o2);
317 EXPECT_TRUE(o1 <= o2);
318 EXPECT_TRUE(o1 <= (o1));
319 EXPECT_TRUE(o1 == (o1));
320 EXPECT_TRUE(o1 != o2);
321 EXPECT_TRUE(o1 >= (o1));
322 EXPECT_TRUE(o2 >= o1);
323 EXPECT_TRUE(o2 > o1);
325 EXPECT_FALSE(o2 < o1);
326 EXPECT_FALSE(o2 <= o1);
327 EXPECT_FALSE(o2 <= o1);
328 EXPECT_FALSE(o2 == o1);
329 EXPECT_FALSE(o1 != (o1));
330 EXPECT_FALSE(o1 >= o2);
331 EXPECT_FALSE(o1 >= o2);
332 EXPECT_FALSE(o1 > o2);
334 /* folly::Optional explicitly doesn't support comparisons with contained value
336 EXPECT_TRUE(1 <= o2);
337 EXPECT_TRUE(1 <= o1);
338 EXPECT_TRUE(1 == o1);
339 EXPECT_TRUE(2 != o1);
340 EXPECT_TRUE(1 >= o1);
341 EXPECT_TRUE(2 >= o1);
344 EXPECT_FALSE(o2 < 1);
345 EXPECT_FALSE(o2 <= 1);
346 EXPECT_FALSE(o2 <= 1);
347 EXPECT_FALSE(o2 == 1);
348 EXPECT_FALSE(o2 != 2);
349 EXPECT_FALSE(o1 >= 2);
350 EXPECT_FALSE(o1 >= 2);
351 EXPECT_FALSE(o1 > 2);
354 // boost::optional does support comparison with contained value, which can
355 // lead to confusion when a bool is contained
356 boost::optional<int> boi(3);
357 EXPECT_TRUE(boi < 5);
358 EXPECT_TRUE(boi <= 4);
359 EXPECT_TRUE(boi == 3);
360 EXPECT_TRUE(boi != 2);
361 EXPECT_TRUE(boi >= 1);
362 EXPECT_TRUE(boi > 0);
363 EXPECT_TRUE(1 < boi);
364 EXPECT_TRUE(2 <= boi);
365 EXPECT_TRUE(3 == boi);
366 EXPECT_TRUE(4 != boi);
367 EXPECT_TRUE(5 >= boi);
368 EXPECT_TRUE(6 > boi);
370 boost::optional<bool> bob(false);
371 EXPECT_TRUE((bool)bob);
372 EXPECT_TRUE(bob == false); // well that was confusing
373 EXPECT_FALSE(bob != false);
376 TEST(Optional, HeterogeneousComparisons) {
377 using opt8 = Optional<uint8_t>;
378 using opt64 = Optional<uint64_t>;
380 EXPECT_TRUE(opt8(4) == uint64_t(4));
381 EXPECT_FALSE(opt8(8) == uint64_t(4));
382 EXPECT_FALSE(opt8() == uint64_t(4));
384 EXPECT_TRUE(uint64_t(4) == opt8(4));
385 EXPECT_FALSE(uint64_t(4) == opt8(8));
386 EXPECT_FALSE(uint64_t(4) == opt8());
388 EXPECT_FALSE(opt8(4) != uint64_t(4));
389 EXPECT_TRUE(opt8(8) != uint64_t(4));
390 EXPECT_TRUE(opt8() != uint64_t(4));
392 EXPECT_FALSE(uint64_t(4) != opt8(4));
393 EXPECT_TRUE(uint64_t(4) != opt8(8));
394 EXPECT_TRUE(uint64_t(4) != opt8());
396 EXPECT_TRUE(opt8() == opt64());
397 EXPECT_TRUE(opt8(4) == opt64(4));
398 EXPECT_FALSE(opt8(8) == opt64(4));
399 EXPECT_FALSE(opt8() == opt64(4));
400 EXPECT_FALSE(opt8(4) == opt64());
402 EXPECT_FALSE(opt8() != opt64());
403 EXPECT_FALSE(opt8(4) != opt64(4));
404 EXPECT_TRUE(opt8(8) != opt64(4));
405 EXPECT_TRUE(opt8() != opt64(4));
406 EXPECT_TRUE(opt8(4) != opt64());
408 EXPECT_TRUE(opt8() < opt64(4));
409 EXPECT_TRUE(opt8(4) < opt64(8));
410 EXPECT_FALSE(opt8() < opt64());
411 EXPECT_FALSE(opt8(4) < opt64(4));
412 EXPECT_FALSE(opt8(8) < opt64(4));
413 EXPECT_FALSE(opt8(4) < opt64());
415 EXPECT_FALSE(opt8() > opt64(4));
416 EXPECT_FALSE(opt8(4) > opt64(8));
417 EXPECT_FALSE(opt8() > opt64());
418 EXPECT_FALSE(opt8(4) > opt64(4));
419 EXPECT_TRUE(opt8(8) > opt64(4));
420 EXPECT_TRUE(opt8(4) > opt64());
422 EXPECT_TRUE(opt8() <= opt64(4));
423 EXPECT_TRUE(opt8(4) <= opt64(8));
424 EXPECT_TRUE(opt8() <= opt64());
425 EXPECT_TRUE(opt8(4) <= opt64(4));
426 EXPECT_FALSE(opt8(8) <= opt64(4));
427 EXPECT_FALSE(opt8(4) <= opt64());
429 EXPECT_FALSE(opt8() >= opt64(4));
430 EXPECT_FALSE(opt8(4) >= opt64(8));
431 EXPECT_TRUE(opt8() >= opt64());
432 EXPECT_TRUE(opt8(4) >= opt64(4));
433 EXPECT_TRUE(opt8(8) >= opt64(4));
434 EXPECT_TRUE(opt8(4) >= opt64());
437 TEST(Optional, Conversions) {
438 Optional<bool> mbool;
439 Optional<short> mshort;
440 Optional<char*> mstr;
443 //These don't compile
452 // intended explicit operator bool, for if (opt).
456 // Truthy tests work and are not ambiguous
457 if (mbool && mshort && mstr && mint) { // only checks not-empty
458 if (*mbool && *mshort && *mstr && *mint) { // only checks value
464 EXPECT_TRUE(bool(mbool));
465 EXPECT_FALSE(*mbool);
468 EXPECT_TRUE(bool(mbool));
472 EXPECT_FALSE(bool(mbool));
474 // No conversion allowed; does not compile
475 // EXPECT_TRUE(mbool == false);
478 TEST(Optional, Pointee) {
480 EXPECT_FALSE(get_pointer(x));
482 EXPECT_TRUE(get_pointer(x));
484 EXPECT_TRUE(*x == 2);
486 EXPECT_FALSE(get_pointer(x));
489 TEST(Optional, MakeOptional) {
490 // const L-value version
491 const std::string s("abc");
492 auto optStr = make_optional(s);
493 ASSERT_TRUE(optStr.hasValue());
494 EXPECT_EQ(*optStr, "abc");
497 EXPECT_EQ(*optStr, "cde");
500 std::string s2("abc");
501 auto optStr2 = make_optional(s2);
502 ASSERT_TRUE(optStr2.hasValue());
503 EXPECT_EQ(*optStr2, "abc");
505 // it's vital to check that s2 wasn't clobbered
506 EXPECT_EQ(s2, "abc");
508 // L-value reference version
510 auto optStr3 = make_optional(s3);
511 ASSERT_TRUE(optStr3.hasValue());
512 EXPECT_EQ(*optStr3, "abc");
514 EXPECT_EQ(s3, "abc");
516 // R-value ref version
517 unique_ptr<int> pInt(new int(3));
518 auto optIntPtr = make_optional(std::move(pInt));
519 EXPECT_TRUE(pInt.get() == nullptr);
520 ASSERT_TRUE(optIntPtr.hasValue());
521 EXPECT_EQ(**optIntPtr, 3);
524 #if __CLANG_PREREQ(3, 6)
525 # pragma clang diagnostic push
526 # pragma clang diagnostic ignored "-Wself-move"
529 TEST(Optional, SelfAssignment) {
530 Optional<int> a = 42;
532 ASSERT_TRUE(a.hasValue() && a.value() == 42);
534 Optional<int> b = 23333333;
536 ASSERT_TRUE(b.hasValue() && b.value() == 23333333);
539 #if __CLANG_PREREQ(3, 6)
540 # pragma clang diagnostic pop
543 class ContainsOptional {
545 ContainsOptional() { }
546 explicit ContainsOptional(int x) : opt_(x) { }
547 bool hasValue() const { return opt_.hasValue(); }
548 int value() const { return opt_.value(); }
550 ContainsOptional(const ContainsOptional &other) = default;
551 ContainsOptional& operator=(const ContainsOptional &other) = default;
552 ContainsOptional(ContainsOptional &&other) = default;
553 ContainsOptional& operator=(ContainsOptional &&other) = default;
560 * Test that a class containing an Optional can be copy and move assigned.
561 * This was broken under gcc 4.7 until assignment operators were explicitly
564 TEST(Optional, AssignmentContained) {
566 ContainsOptional source(5), target;
568 EXPECT_TRUE(target.hasValue());
569 EXPECT_EQ(5, target.value());
573 ContainsOptional source(5), target;
574 target = std::move(source);
575 EXPECT_TRUE(target.hasValue());
576 EXPECT_EQ(5, target.value());
577 EXPECT_FALSE(source.hasValue());
581 ContainsOptional opt_uninit, target(10);
583 EXPECT_FALSE(target.hasValue());
587 TEST(Optional, Exceptions) {
589 EXPECT_THROW(empty.value(), OptionalEmptyException);
592 TEST(Optional, NoThrowDefaultConstructible) {
593 EXPECT_TRUE(std::is_nothrow_default_constructible<Optional<bool>>::value);
596 struct NoDestructor {};
598 struct WithDestructor {
602 TEST(Optional, TriviallyDestructible) {
603 // These could all be static_asserts but EXPECT_* give much nicer output on
605 EXPECT_TRUE(std::is_trivially_destructible<Optional<NoDestructor>>::value);
606 EXPECT_TRUE(std::is_trivially_destructible<Optional<int>>::value);
607 EXPECT_FALSE(std::is_trivially_destructible<Optional<WithDestructor>>::value);
610 TEST(Optional, Hash) {
611 // Test it's usable in std::unordered map (compile time check)
612 std::unordered_map<Optional<int>, Optional<int>> obj;
613 // Also check the std::hash template can be instantiated by the compiler
614 std::hash<Optional<int>>()(none);
615 std::hash<Optional<int>>()(3);