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_);
129 friend bool operator==(const MoveTester& o1, const MoveTester& o2);
133 bool operator==(const MoveTester& o1, const MoveTester& o2) {
134 return o1.s_ == o2.s_;
137 TEST(Optional, value_or_rvalue_arg) {
138 Optional<MoveTester> opt;
139 MoveTester dflt = "hello";
140 EXPECT_EQ("hello", opt.value_or(dflt));
141 EXPECT_EQ("hello", dflt);
142 EXPECT_EQ("hello", opt.value_or(std::move(dflt)));
144 EXPECT_EQ("world", opt.value_or("world"));
147 // Make sure that the const overload works on const objects
148 const auto& optc = opt;
149 EXPECT_EQ("hello", optc.value_or(dflt));
150 EXPECT_EQ("hello", dflt);
151 EXPECT_EQ("hello", optc.value_or(std::move(dflt)));
153 EXPECT_EQ("world", optc.value_or("world"));
157 EXPECT_EQ("meow", opt.value_or(dflt));
158 EXPECT_EQ("hello", dflt);
159 EXPECT_EQ("meow", opt.value_or(std::move(dflt)));
160 EXPECT_EQ("hello", dflt); // only moved if used
163 TEST(Optional, value_or_noncopyable) {
164 Optional<std::unique_ptr<int>> opt;
165 std::unique_ptr<int> dflt(new int(42));
166 EXPECT_EQ(42, *std::move(opt).value_or(std::move(dflt)));
169 struct ExpectingDeleter {
170 explicit ExpectingDeleter(int expected) : expected(expected) { }
172 void operator()(const int* ptr) {
173 EXPECT_EQ(*ptr, expected);
178 TEST(Optional, value_move) {
179 auto ptr = Optional<std::unique_ptr<int, ExpectingDeleter>>(
180 {new int(42), ExpectingDeleter{1337}}).value();
184 TEST(Optional, dereference_move) {
185 auto ptr = *Optional<std::unique_ptr<int, ExpectingDeleter>>(
186 {new int(42), ExpectingDeleter{1337}});
190 TEST(Optional, EmptyConstruct) {
192 EXPECT_FALSE(bool(opt));
193 Optional<int> test1(opt);
194 EXPECT_FALSE(bool(test1));
195 Optional<int> test2(std::move(opt));
196 EXPECT_FALSE(bool(test2));
199 TEST(Optional, InPlaceConstruct) {
200 using A = std::pair<int, double>;
201 Optional<A> opt(in_place, 5, 3.2);
202 EXPECT_TRUE(bool(opt));
203 EXPECT_EQ(5, opt->first);
206 TEST(Optional, InPlaceNestedConstruct) {
207 using A = std::pair<int, double>;
208 Optional<Optional<A>> opt(in_place, in_place, 5, 3.2);
209 EXPECT_TRUE(bool(opt));
210 EXPECT_TRUE(bool(*opt));
211 EXPECT_EQ(5, (*opt)->first);
214 TEST(Optional, Unique) {
215 Optional<unique_ptr<int>> opt;
218 EXPECT_FALSE(bool(opt));
220 opt.emplace(new int(5));
221 EXPECT_TRUE(bool(opt));
226 opt = unique_ptr<int>(new int(6));
229 opt = unique_ptr<int>(new int(7));
232 // move it out by move construct
233 Optional<unique_ptr<int>> moved(std::move(opt));
234 EXPECT_TRUE(bool(moved));
235 EXPECT_FALSE(bool(opt));
236 EXPECT_EQ(7, **moved);
238 EXPECT_TRUE(bool(moved));
239 opt = std::move(moved); // move it back by move assign
240 EXPECT_FALSE(bool(moved));
241 EXPECT_TRUE(bool(opt));
245 TEST(Optional, Shared) {
247 Optional<shared_ptr<int>> opt;
248 EXPECT_FALSE(bool(opt));
250 opt.emplace(new int(5));
251 EXPECT_TRUE(bool(opt));
253 EXPECT_EQ(ptr.get(), opt->get());
254 EXPECT_EQ(2, ptr.use_count());
256 EXPECT_EQ(1, ptr.use_count());
259 EXPECT_EQ(2, ptr.use_count());
260 EXPECT_EQ(ptr.get(), opt->get());
262 EXPECT_EQ(1, ptr.use_count());
264 opt = std::move(ptr);
265 EXPECT_EQ(1, opt->use_count());
266 EXPECT_EQ(nullptr, ptr.get());
268 Optional<shared_ptr<int>> copied(opt);
269 EXPECT_EQ(2, opt->use_count());
270 Optional<shared_ptr<int>> moved(std::move(opt));
271 EXPECT_EQ(2, moved->use_count());
272 moved.emplace(new int(6));
273 EXPECT_EQ(1, moved->use_count());
275 EXPECT_EQ(2, moved->use_count());
279 TEST(Optional, Order) {
280 std::vector<Optional<int>> vect{
287 std::vector<Optional<int>> expected {
294 std::sort(vect.begin(), vect.end());
295 EXPECT_EQ(vect, expected);
298 TEST(Optional, Swap) {
299 Optional<std::string> a;
300 Optional<std::string> b;
303 EXPECT_FALSE(a.hasValue());
304 EXPECT_FALSE(b.hasValue());
307 EXPECT_TRUE(a.hasValue());
308 EXPECT_FALSE(b.hasValue());
309 EXPECT_EQ("hello", a.value());
312 EXPECT_FALSE(a.hasValue());
313 EXPECT_TRUE(b.hasValue());
314 EXPECT_EQ("hello", b.value());
317 EXPECT_TRUE(a.hasValue());
318 EXPECT_EQ("bye", a.value());
323 TEST(Optional, Comparisons) {
328 EXPECT_TRUE(o_ <= (o_));
329 EXPECT_TRUE(o_ == (o_));
330 EXPECT_TRUE(o_ >= (o_));
332 EXPECT_TRUE(o1 < o2);
333 EXPECT_TRUE(o1 <= o2);
334 EXPECT_TRUE(o1 <= (o1));
335 EXPECT_TRUE(o1 == (o1));
336 EXPECT_TRUE(o1 != o2);
337 EXPECT_TRUE(o1 >= (o1));
338 EXPECT_TRUE(o2 >= o1);
339 EXPECT_TRUE(o2 > o1);
341 EXPECT_FALSE(o2 < o1);
342 EXPECT_FALSE(o2 <= o1);
343 EXPECT_FALSE(o2 <= o1);
344 EXPECT_FALSE(o2 == o1);
345 EXPECT_FALSE(o1 != (o1));
346 EXPECT_FALSE(o1 >= o2);
347 EXPECT_FALSE(o1 >= o2);
348 EXPECT_FALSE(o1 > o2);
350 /* folly::Optional explicitly doesn't support comparisons with contained value
352 EXPECT_TRUE(1 <= o2);
353 EXPECT_TRUE(1 <= o1);
354 EXPECT_TRUE(1 == o1);
355 EXPECT_TRUE(2 != o1);
356 EXPECT_TRUE(1 >= o1);
357 EXPECT_TRUE(2 >= o1);
360 EXPECT_FALSE(o2 < 1);
361 EXPECT_FALSE(o2 <= 1);
362 EXPECT_FALSE(o2 <= 1);
363 EXPECT_FALSE(o2 == 1);
364 EXPECT_FALSE(o2 != 2);
365 EXPECT_FALSE(o1 >= 2);
366 EXPECT_FALSE(o1 >= 2);
367 EXPECT_FALSE(o1 > 2);
370 // boost::optional does support comparison with contained value, which can
371 // lead to confusion when a bool is contained
372 boost::optional<int> boi(3);
373 EXPECT_TRUE(boi < 5);
374 EXPECT_TRUE(boi <= 4);
375 EXPECT_TRUE(boi == 3);
376 EXPECT_TRUE(boi != 2);
377 EXPECT_TRUE(boi >= 1);
378 EXPECT_TRUE(boi > 0);
379 EXPECT_TRUE(1 < boi);
380 EXPECT_TRUE(2 <= boi);
381 EXPECT_TRUE(3 == boi);
382 EXPECT_TRUE(4 != boi);
383 EXPECT_TRUE(5 >= boi);
384 EXPECT_TRUE(6 > boi);
386 boost::optional<bool> bob(false);
387 EXPECT_TRUE((bool)bob);
388 EXPECT_TRUE(bob == false); // well that was confusing
389 EXPECT_FALSE(bob != false);
392 TEST(Optional, HeterogeneousComparisons) {
393 using opt8 = Optional<uint8_t>;
394 using opt64 = Optional<uint64_t>;
396 EXPECT_TRUE(opt8(4) == uint64_t(4));
397 EXPECT_FALSE(opt8(8) == uint64_t(4));
398 EXPECT_FALSE(opt8() == uint64_t(4));
400 EXPECT_TRUE(uint64_t(4) == opt8(4));
401 EXPECT_FALSE(uint64_t(4) == opt8(8));
402 EXPECT_FALSE(uint64_t(4) == opt8());
404 EXPECT_FALSE(opt8(4) != uint64_t(4));
405 EXPECT_TRUE(opt8(8) != uint64_t(4));
406 EXPECT_TRUE(opt8() != uint64_t(4));
408 EXPECT_FALSE(uint64_t(4) != opt8(4));
409 EXPECT_TRUE(uint64_t(4) != opt8(8));
410 EXPECT_TRUE(uint64_t(4) != opt8());
412 EXPECT_TRUE(opt8() == opt64());
413 EXPECT_TRUE(opt8(4) == opt64(4));
414 EXPECT_FALSE(opt8(8) == opt64(4));
415 EXPECT_FALSE(opt8() == opt64(4));
416 EXPECT_FALSE(opt8(4) == opt64());
418 EXPECT_FALSE(opt8() != opt64());
419 EXPECT_FALSE(opt8(4) != opt64(4));
420 EXPECT_TRUE(opt8(8) != opt64(4));
421 EXPECT_TRUE(opt8() != opt64(4));
422 EXPECT_TRUE(opt8(4) != opt64());
424 EXPECT_TRUE(opt8() < opt64(4));
425 EXPECT_TRUE(opt8(4) < opt64(8));
426 EXPECT_FALSE(opt8() < opt64());
427 EXPECT_FALSE(opt8(4) < opt64(4));
428 EXPECT_FALSE(opt8(8) < opt64(4));
429 EXPECT_FALSE(opt8(4) < opt64());
431 EXPECT_FALSE(opt8() > opt64(4));
432 EXPECT_FALSE(opt8(4) > opt64(8));
433 EXPECT_FALSE(opt8() > opt64());
434 EXPECT_FALSE(opt8(4) > opt64(4));
435 EXPECT_TRUE(opt8(8) > opt64(4));
436 EXPECT_TRUE(opt8(4) > opt64());
438 EXPECT_TRUE(opt8() <= opt64(4));
439 EXPECT_TRUE(opt8(4) <= opt64(8));
440 EXPECT_TRUE(opt8() <= opt64());
441 EXPECT_TRUE(opt8(4) <= opt64(4));
442 EXPECT_FALSE(opt8(8) <= opt64(4));
443 EXPECT_FALSE(opt8(4) <= opt64());
445 EXPECT_FALSE(opt8() >= opt64(4));
446 EXPECT_FALSE(opt8(4) >= opt64(8));
447 EXPECT_TRUE(opt8() >= opt64());
448 EXPECT_TRUE(opt8(4) >= opt64(4));
449 EXPECT_TRUE(opt8(8) >= opt64(4));
450 EXPECT_TRUE(opt8(4) >= opt64());
453 TEST(Optional, Conversions) {
454 Optional<bool> mbool;
455 Optional<short> mshort;
456 Optional<char*> mstr;
459 //These don't compile
468 // intended explicit operator bool, for if (opt).
472 // Truthy tests work and are not ambiguous
473 if (mbool && mshort && mstr && mint) { // only checks not-empty
474 if (*mbool && *mshort && *mstr && *mint) { // only checks value
480 EXPECT_TRUE(bool(mbool));
481 EXPECT_FALSE(*mbool);
484 EXPECT_TRUE(bool(mbool));
488 EXPECT_FALSE(bool(mbool));
490 // No conversion allowed; does not compile
491 // EXPECT_TRUE(mbool == false);
494 TEST(Optional, Pointee) {
496 EXPECT_FALSE(get_pointer(x));
498 EXPECT_TRUE(get_pointer(x));
500 EXPECT_TRUE(*x == 2);
502 EXPECT_FALSE(get_pointer(x));
505 TEST(Optional, MakeOptional) {
506 // const L-value version
507 const std::string s("abc");
508 auto optStr = make_optional(s);
509 ASSERT_TRUE(optStr.hasValue());
510 EXPECT_EQ(*optStr, "abc");
513 EXPECT_EQ(*optStr, "cde");
516 std::string s2("abc");
517 auto optStr2 = make_optional(s2);
518 ASSERT_TRUE(optStr2.hasValue());
519 EXPECT_EQ(*optStr2, "abc");
521 // it's vital to check that s2 wasn't clobbered
522 EXPECT_EQ(s2, "abc");
524 // L-value reference version
526 auto optStr3 = make_optional(s3);
527 ASSERT_TRUE(optStr3.hasValue());
528 EXPECT_EQ(*optStr3, "abc");
530 EXPECT_EQ(s3, "abc");
532 // R-value ref version
533 unique_ptr<int> pInt(new int(3));
534 auto optIntPtr = make_optional(std::move(pInt));
535 EXPECT_TRUE(pInt.get() == nullptr);
536 ASSERT_TRUE(optIntPtr.hasValue());
537 EXPECT_EQ(**optIntPtr, 3);
540 #if __CLANG_PREREQ(3, 6)
541 # pragma clang diagnostic push
542 # pragma clang diagnostic ignored "-Wself-move"
545 TEST(Optional, SelfAssignment) {
546 Optional<int> a = 42;
548 ASSERT_TRUE(a.hasValue() && a.value() == 42);
550 Optional<int> b = 23333333;
552 ASSERT_TRUE(b.hasValue() && b.value() == 23333333);
555 #if __CLANG_PREREQ(3, 6)
556 # pragma clang diagnostic pop
559 class ContainsOptional {
561 ContainsOptional() { }
562 explicit ContainsOptional(int x) : opt_(x) { }
563 bool hasValue() const { return opt_.hasValue(); }
564 int value() const { return opt_.value(); }
566 ContainsOptional(const ContainsOptional &other) = default;
567 ContainsOptional& operator=(const ContainsOptional &other) = default;
568 ContainsOptional(ContainsOptional &&other) = default;
569 ContainsOptional& operator=(ContainsOptional &&other) = default;
576 * Test that a class containing an Optional can be copy and move assigned.
577 * This was broken under gcc 4.7 until assignment operators were explicitly
580 TEST(Optional, AssignmentContained) {
582 ContainsOptional source(5), target;
584 EXPECT_TRUE(target.hasValue());
585 EXPECT_EQ(5, target.value());
589 ContainsOptional source(5), target;
590 target = std::move(source);
591 EXPECT_TRUE(target.hasValue());
592 EXPECT_EQ(5, target.value());
593 EXPECT_FALSE(source.hasValue());
597 ContainsOptional opt_uninit, target(10);
599 EXPECT_FALSE(target.hasValue());
603 TEST(Optional, Exceptions) {
605 EXPECT_THROW(empty.value(), OptionalEmptyException);
608 TEST(Optional, NoThrowDefaultConstructible) {
609 EXPECT_TRUE(std::is_nothrow_default_constructible<Optional<bool>>::value);
612 struct NoDestructor {};
614 struct WithDestructor {
618 TEST(Optional, TriviallyDestructible) {
619 // These could all be static_asserts but EXPECT_* give much nicer output on
621 EXPECT_TRUE(std::is_trivially_destructible<Optional<NoDestructor>>::value);
622 EXPECT_TRUE(std::is_trivially_destructible<Optional<int>>::value);
623 EXPECT_FALSE(std::is_trivially_destructible<Optional<WithDestructor>>::value);
626 TEST(Optional, Hash) {
627 // Test it's usable in std::unordered map (compile time check)
628 std::unordered_map<Optional<int>, Optional<int>> obj;
629 // Also check the std::hash template can be instantiated by the compiler
630 std::hash<Optional<int>>()(none);
631 std::hash<Optional<int>>()(3);