2 * Copyright 2016 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>
25 #include <type_traits>
27 #include <glog/logging.h>
28 #include <gtest/gtest.h>
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_life_extention) {
178 // Extends the life of the value.
179 const auto& ptr = Optional<std::unique_ptr<int, ExpectingDeleter>>(
180 {new int(42), ExpectingDeleter{1337}}).value();
184 TEST(Optional, value_move) {
185 auto ptr = Optional<std::unique_ptr<int, ExpectingDeleter>>(
186 {new int(42), ExpectingDeleter{1337}}).value();
190 TEST(Optional, dereference_life_extention) {
191 // Extends the life of the value.
192 const auto& ptr = *Optional<std::unique_ptr<int, ExpectingDeleter>>(
193 {new int(42), ExpectingDeleter{1337}});
197 TEST(Optional, dereference_move) {
198 auto ptr = *Optional<std::unique_ptr<int, ExpectingDeleter>>(
199 {new int(42), ExpectingDeleter{1337}});
203 TEST(Optional, EmptyConstruct) {
205 EXPECT_FALSE(bool(opt));
206 Optional<int> test1(opt);
207 EXPECT_FALSE(bool(test1));
208 Optional<int> test2(std::move(opt));
209 EXPECT_FALSE(bool(test2));
212 TEST(Optional, Unique) {
213 Optional<unique_ptr<int>> opt;
216 EXPECT_FALSE(bool(opt));
218 opt.emplace(new int(5));
219 EXPECT_TRUE(bool(opt));
224 opt = unique_ptr<int>(new int(6));
227 opt = unique_ptr<int>(new int(7));
230 // move it out by move construct
231 Optional<unique_ptr<int>> moved(std::move(opt));
232 EXPECT_TRUE(bool(moved));
233 EXPECT_FALSE(bool(opt));
234 EXPECT_EQ(7, **moved);
236 EXPECT_TRUE(bool(moved));
237 opt = std::move(moved); // move it back by move assign
238 EXPECT_FALSE(bool(moved));
239 EXPECT_TRUE(bool(opt));
243 TEST(Optional, Shared) {
245 Optional<shared_ptr<int>> opt;
246 EXPECT_FALSE(bool(opt));
248 opt.emplace(new int(5));
249 EXPECT_TRUE(bool(opt));
251 EXPECT_EQ(ptr.get(), opt->get());
252 EXPECT_EQ(2, ptr.use_count());
254 EXPECT_EQ(1, ptr.use_count());
257 EXPECT_EQ(2, ptr.use_count());
258 EXPECT_EQ(ptr.get(), opt->get());
260 EXPECT_EQ(1, ptr.use_count());
262 opt = std::move(ptr);
263 EXPECT_EQ(1, opt->use_count());
264 EXPECT_EQ(nullptr, ptr.get());
266 Optional<shared_ptr<int>> copied(opt);
267 EXPECT_EQ(2, opt->use_count());
268 Optional<shared_ptr<int>> moved(std::move(opt));
269 EXPECT_EQ(2, moved->use_count());
270 moved.emplace(new int(6));
271 EXPECT_EQ(1, moved->use_count());
273 EXPECT_EQ(2, moved->use_count());
277 TEST(Optional, Order) {
278 std::vector<Optional<int>> vect{
285 std::vector<Optional<int>> expected {
292 std::sort(vect.begin(), vect.end());
293 EXPECT_EQ(vect, expected);
296 TEST(Optional, Swap) {
297 Optional<std::string> a;
298 Optional<std::string> b;
301 EXPECT_FALSE(a.hasValue());
302 EXPECT_FALSE(b.hasValue());
305 EXPECT_TRUE(a.hasValue());
306 EXPECT_FALSE(b.hasValue());
307 EXPECT_EQ("hello", a.value());
310 EXPECT_FALSE(a.hasValue());
311 EXPECT_TRUE(b.hasValue());
312 EXPECT_EQ("hello", b.value());
315 EXPECT_TRUE(a.hasValue());
316 EXPECT_EQ("bye", a.value());
321 TEST(Optional, Comparisons) {
326 EXPECT_TRUE(o_ <= (o_));
327 EXPECT_TRUE(o_ == (o_));
328 EXPECT_TRUE(o_ >= (o_));
330 EXPECT_TRUE(o1 < o2);
331 EXPECT_TRUE(o1 <= o2);
332 EXPECT_TRUE(o1 <= (o1));
333 EXPECT_TRUE(o1 == (o1));
334 EXPECT_TRUE(o1 != o2);
335 EXPECT_TRUE(o1 >= (o1));
336 EXPECT_TRUE(o2 >= o1);
337 EXPECT_TRUE(o2 > o1);
339 EXPECT_FALSE(o2 < o1);
340 EXPECT_FALSE(o2 <= o1);
341 EXPECT_FALSE(o2 <= o1);
342 EXPECT_FALSE(o2 == o1);
343 EXPECT_FALSE(o1 != (o1));
344 EXPECT_FALSE(o1 >= o2);
345 EXPECT_FALSE(o1 >= o2);
346 EXPECT_FALSE(o1 > o2);
348 /* folly::Optional explicitly doesn't support comparisons with contained value
350 EXPECT_TRUE(1 <= o2);
351 EXPECT_TRUE(1 <= o1);
352 EXPECT_TRUE(1 == o1);
353 EXPECT_TRUE(2 != o1);
354 EXPECT_TRUE(1 >= o1);
355 EXPECT_TRUE(2 >= o1);
358 EXPECT_FALSE(o2 < 1);
359 EXPECT_FALSE(o2 <= 1);
360 EXPECT_FALSE(o2 <= 1);
361 EXPECT_FALSE(o2 == 1);
362 EXPECT_FALSE(o2 != 2);
363 EXPECT_FALSE(o1 >= 2);
364 EXPECT_FALSE(o1 >= 2);
365 EXPECT_FALSE(o1 > 2);
368 // boost::optional does support comparison with contained value, which can
369 // lead to confusion when a bool is contained
370 boost::optional<int> boi(3);
371 EXPECT_TRUE(boi < 5);
372 EXPECT_TRUE(boi <= 4);
373 EXPECT_TRUE(boi == 3);
374 EXPECT_TRUE(boi != 2);
375 EXPECT_TRUE(boi >= 1);
376 EXPECT_TRUE(boi > 0);
377 EXPECT_TRUE(1 < boi);
378 EXPECT_TRUE(2 <= boi);
379 EXPECT_TRUE(3 == boi);
380 EXPECT_TRUE(4 != boi);
381 EXPECT_TRUE(5 >= boi);
382 EXPECT_TRUE(6 > boi);
384 boost::optional<bool> bob(false);
385 EXPECT_TRUE((bool)bob);
386 EXPECT_TRUE(bob == false); // well that was confusing
387 EXPECT_FALSE(bob != false);
390 TEST(Optional, Conversions) {
391 Optional<bool> mbool;
392 Optional<short> mshort;
393 Optional<char*> mstr;
396 //These don't compile
405 // intended explicit operator bool, for if (opt).
409 // Truthy tests work and are not ambiguous
410 if (mbool && mshort && mstr && mint) { // only checks not-empty
411 if (*mbool && *mshort && *mstr && *mint) { // only checks value
417 EXPECT_TRUE(bool(mbool));
418 EXPECT_FALSE(*mbool);
421 EXPECT_TRUE(bool(mbool));
425 EXPECT_FALSE(bool(mbool));
427 // No conversion allowed; does not compile
428 // EXPECT_TRUE(mbool == false);
431 TEST(Optional, Pointee) {
433 EXPECT_FALSE(get_pointer(x));
435 EXPECT_TRUE(get_pointer(x));
437 EXPECT_TRUE(*x == 2);
439 EXPECT_FALSE(get_pointer(x));
442 TEST(Optional, MakeOptional) {
443 // const L-value version
444 const std::string s("abc");
445 auto optStr = make_optional(s);
446 ASSERT_TRUE(optStr.hasValue());
447 EXPECT_EQ(*optStr, "abc");
450 EXPECT_EQ(*optStr, "cde");
453 std::string s2("abc");
454 auto optStr2 = make_optional(s2);
455 ASSERT_TRUE(optStr2.hasValue());
456 EXPECT_EQ(*optStr2, "abc");
458 // it's vital to check that s2 wasn't clobbered
459 EXPECT_EQ(s2, "abc");
461 // L-value reference version
463 auto optStr3 = make_optional(s3);
464 ASSERT_TRUE(optStr3.hasValue());
465 EXPECT_EQ(*optStr3, "abc");
467 EXPECT_EQ(s3, "abc");
469 // R-value ref version
470 unique_ptr<int> pInt(new int(3));
471 auto optIntPtr = make_optional(std::move(pInt));
472 EXPECT_TRUE(pInt.get() == nullptr);
473 ASSERT_TRUE(optIntPtr.hasValue());
474 EXPECT_EQ(**optIntPtr, 3);
477 #if __CLANG_PREREQ(3, 6)
478 # pragma clang diagnostic push
479 # pragma clang diagnostic ignored "-Wself-move"
482 TEST(Optional, SelfAssignment) {
483 Optional<int> a = 42;
485 ASSERT_TRUE(a.hasValue() && a.value() == 42);
487 Optional<int> b = 23333333;
489 ASSERT_TRUE(b.hasValue() && b.value() == 23333333);
492 #if __CLANG_PREREQ(3, 6)
493 # pragma clang diagnostic pop
496 class ContainsOptional {
498 ContainsOptional() { }
499 explicit ContainsOptional(int x) : opt_(x) { }
500 bool hasValue() const { return opt_.hasValue(); }
501 int value() const { return opt_.value(); }
503 ContainsOptional(const ContainsOptional &other) = default;
504 ContainsOptional& operator=(const ContainsOptional &other) = default;
505 ContainsOptional(ContainsOptional &&other) = default;
506 ContainsOptional& operator=(ContainsOptional &&other) = default;
513 * Test that a class containing an Optional can be copy and move assigned.
514 * This was broken under gcc 4.7 until assignment operators were explicitly
517 TEST(Optional, AssignmentContained) {
519 ContainsOptional source(5), target;
521 EXPECT_TRUE(target.hasValue());
522 EXPECT_EQ(5, target.value());
526 ContainsOptional source(5), target;
527 target = std::move(source);
528 EXPECT_TRUE(target.hasValue());
529 EXPECT_EQ(5, target.value());
530 EXPECT_FALSE(source.hasValue());
534 ContainsOptional opt_uninit, target(10);
536 EXPECT_FALSE(target.hasValue());
540 TEST(Optional, Exceptions) {
542 EXPECT_THROW(empty.value(), OptionalEmptyException);
545 TEST(Optional, NoThrowDefaultConstructible) {
546 EXPECT_TRUE(std::is_nothrow_default_constructible<Optional<bool>>::value);
549 struct NoDestructor {};
551 struct WithDestructor {
555 TEST(Optional, TriviallyDestructible) {
556 // These could all be static_asserts but EXPECT_* give much nicer output on
558 EXPECT_TRUE(std::is_trivially_destructible<Optional<NoDestructor>>::value);
559 EXPECT_TRUE(std::is_trivially_destructible<Optional<int>>::value);
560 EXPECT_FALSE(std::is_trivially_destructible<Optional<WithDestructor>>::value);