2 * Copyright 2015 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>
24 #include <type_traits>
26 #include <glog/logging.h>
27 #include <gtest/gtest.h>
28 #include <boost/optional.hpp>
30 using std::unique_ptr;
31 using std::shared_ptr;
36 std::ostream& operator<<(std::ostream& os, const Optional<V>& v) {
38 os << "Optional(" << v.value() << ')';
46 NoDefault(int, int) {}
50 static_assert(sizeof(Optional<char>) == 2, "");
51 static_assert(sizeof(Optional<int>) == 8, "");
52 static_assert(sizeof(Optional<NoDefault>) == 4, "");
53 static_assert(sizeof(Optional<char>) == sizeof(boost::optional<char>), "");
54 static_assert(sizeof(Optional<short>) == sizeof(boost::optional<short>), "");
55 static_assert(sizeof(Optional<int>) == sizeof(boost::optional<int>), "");
56 static_assert(sizeof(Optional<double>) == sizeof(boost::optional<double>), "");
58 TEST(Optional, NoDefault) {
59 Optional<NoDefault> x;
67 TEST(Optional, String) {
68 Optional<std::string> maybeString;
69 EXPECT_FALSE(maybeString);
70 maybeString = "hello";
71 EXPECT_TRUE(bool(maybeString));
74 TEST(Optional, Const) {
75 { // default construct
76 Optional<const int> opt;
77 EXPECT_FALSE(bool(opt));
83 EXPECT_FALSE(bool(opt));
87 Optional<const int> opt(x);
92 Optional<const int> opt(std::move(x));
95 // no assignment allowed
98 TEST(Optional, Simple) {
100 EXPECT_FALSE(bool(opt));
101 EXPECT_EQ(42, opt.value_or(42));
103 EXPECT_TRUE(bool(opt));
105 EXPECT_EQ(4, opt.value_or(42));
109 EXPECT_FALSE(bool(opt));
114 /* implicit */ MoveTester(const char* s) : s_(s) {}
115 MoveTester(const MoveTester&) = default;
116 MoveTester(MoveTester&& other) noexcept {
117 s_ = std::move(other.s_);
120 MoveTester& operator=(const MoveTester&) = default;
121 MoveTester& operator=(MoveTester&& other) noexcept {
122 s_ = std::move(other.s_);
127 friend bool operator==(const MoveTester& o1, const MoveTester& o2);
131 bool operator==(const MoveTester& o1, const MoveTester& o2) {
132 return o1.s_ == o2.s_;
135 TEST(Optional, value_or_rvalue_arg) {
136 Optional<MoveTester> opt;
137 MoveTester dflt = "hello";
138 EXPECT_EQ("hello", opt.value_or(dflt));
139 EXPECT_EQ("hello", dflt);
140 EXPECT_EQ("hello", opt.value_or(std::move(dflt)));
142 EXPECT_EQ("world", opt.value_or("world"));
145 // Make sure that the const overload works on const objects
146 const auto& optc = opt;
147 EXPECT_EQ("hello", optc.value_or(dflt));
148 EXPECT_EQ("hello", dflt);
149 EXPECT_EQ("hello", optc.value_or(std::move(dflt)));
151 EXPECT_EQ("world", optc.value_or("world"));
155 EXPECT_EQ("meow", opt.value_or(dflt));
156 EXPECT_EQ("hello", dflt);
157 EXPECT_EQ("meow", opt.value_or(std::move(dflt)));
158 EXPECT_EQ("hello", dflt); // only moved if used
161 TEST(Optional, value_or_noncopyable) {
162 Optional<std::unique_ptr<int>> opt;
163 std::unique_ptr<int> dflt(new int(42));
164 EXPECT_EQ(42, *std::move(opt).value_or(std::move(dflt)));
167 struct ExpectingDeleter {
168 explicit ExpectingDeleter(int expected) : expected(expected) { }
170 void operator()(const int* ptr) {
171 EXPECT_EQ(*ptr, expected);
176 TEST(Optional, value_life_extention) {
177 // Extends the life of the value.
178 const auto& ptr = Optional<std::unique_ptr<int, ExpectingDeleter>>(
179 {new int(42), ExpectingDeleter{1337}}).value();
183 TEST(Optional, value_move) {
184 auto ptr = Optional<std::unique_ptr<int, ExpectingDeleter>>(
185 {new int(42), ExpectingDeleter{1337}}).value();
189 TEST(Optional, dereference_life_extention) {
190 // Extends the life of the value.
191 const auto& ptr = *Optional<std::unique_ptr<int, ExpectingDeleter>>(
192 {new int(42), ExpectingDeleter{1337}});
196 TEST(Optional, dereference_move) {
197 auto ptr = *Optional<std::unique_ptr<int, ExpectingDeleter>>(
198 {new int(42), ExpectingDeleter{1337}});
202 TEST(Optional, EmptyConstruct) {
204 EXPECT_FALSE(bool(opt));
205 Optional<int> test1(opt);
206 EXPECT_FALSE(bool(test1));
207 Optional<int> test2(std::move(opt));
208 EXPECT_FALSE(bool(test2));
211 TEST(Optional, Unique) {
212 Optional<unique_ptr<int>> opt;
215 EXPECT_FALSE(bool(opt));
217 opt.emplace(new int(5));
218 EXPECT_TRUE(bool(opt));
223 opt = unique_ptr<int>(new int(6));
226 opt = unique_ptr<int>(new int(7));
229 // move it out by move construct
230 Optional<unique_ptr<int>> moved(std::move(opt));
231 EXPECT_TRUE(bool(moved));
232 EXPECT_FALSE(bool(opt));
233 EXPECT_EQ(7, **moved);
235 EXPECT_TRUE(bool(moved));
236 opt = std::move(moved); // move it back by move assign
237 EXPECT_FALSE(bool(moved));
238 EXPECT_TRUE(bool(opt));
242 TEST(Optional, Shared) {
244 Optional<shared_ptr<int>> opt;
245 EXPECT_FALSE(bool(opt));
247 opt.emplace(new int(5));
248 EXPECT_TRUE(bool(opt));
250 EXPECT_EQ(ptr.get(), opt->get());
251 EXPECT_EQ(2, ptr.use_count());
253 EXPECT_EQ(1, ptr.use_count());
256 EXPECT_EQ(2, ptr.use_count());
257 EXPECT_EQ(ptr.get(), opt->get());
259 EXPECT_EQ(1, ptr.use_count());
261 opt = std::move(ptr);
262 EXPECT_EQ(1, opt->use_count());
263 EXPECT_EQ(nullptr, ptr.get());
265 Optional<shared_ptr<int>> copied(opt);
266 EXPECT_EQ(2, opt->use_count());
267 Optional<shared_ptr<int>> moved(std::move(opt));
268 EXPECT_EQ(2, moved->use_count());
269 moved.emplace(new int(6));
270 EXPECT_EQ(1, moved->use_count());
272 EXPECT_EQ(2, moved->use_count());
276 TEST(Optional, Order) {
277 std::vector<Optional<int>> vect{
284 std::vector<Optional<int>> expected {
291 std::sort(vect.begin(), vect.end());
292 EXPECT_EQ(vect, expected);
295 TEST(Optional, Swap) {
296 Optional<std::string> a;
297 Optional<std::string> b;
300 EXPECT_FALSE(a.hasValue());
301 EXPECT_FALSE(b.hasValue());
304 EXPECT_TRUE(a.hasValue());
305 EXPECT_FALSE(b.hasValue());
306 EXPECT_EQ("hello", a.value());
309 EXPECT_FALSE(a.hasValue());
310 EXPECT_TRUE(b.hasValue());
311 EXPECT_EQ("hello", b.value());
314 EXPECT_TRUE(a.hasValue());
315 EXPECT_EQ("bye", a.value());
320 TEST(Optional, Comparisons) {
325 EXPECT_TRUE(o_ <= (o_));
326 EXPECT_TRUE(o_ == (o_));
327 EXPECT_TRUE(o_ >= (o_));
329 EXPECT_TRUE(o1 < o2);
330 EXPECT_TRUE(o1 <= o2);
331 EXPECT_TRUE(o1 <= (o1));
332 EXPECT_TRUE(o1 == (o1));
333 EXPECT_TRUE(o1 != o2);
334 EXPECT_TRUE(o1 >= (o1));
335 EXPECT_TRUE(o2 >= o1);
336 EXPECT_TRUE(o2 > o1);
338 EXPECT_FALSE(o2 < o1);
339 EXPECT_FALSE(o2 <= o1);
340 EXPECT_FALSE(o2 <= o1);
341 EXPECT_FALSE(o2 == o1);
342 EXPECT_FALSE(o1 != (o1));
343 EXPECT_FALSE(o1 >= o2);
344 EXPECT_FALSE(o1 >= o2);
345 EXPECT_FALSE(o1 > o2);
347 /* folly::Optional explicitly doesn't support comparisons with contained value
349 EXPECT_TRUE(1 <= o2);
350 EXPECT_TRUE(1 <= o1);
351 EXPECT_TRUE(1 == o1);
352 EXPECT_TRUE(2 != o1);
353 EXPECT_TRUE(1 >= o1);
354 EXPECT_TRUE(2 >= o1);
357 EXPECT_FALSE(o2 < 1);
358 EXPECT_FALSE(o2 <= 1);
359 EXPECT_FALSE(o2 <= 1);
360 EXPECT_FALSE(o2 == 1);
361 EXPECT_FALSE(o2 != 2);
362 EXPECT_FALSE(o1 >= 2);
363 EXPECT_FALSE(o1 >= 2);
364 EXPECT_FALSE(o1 > 2);
367 // boost::optional does support comparison with contained value, which can
368 // lead to confusion when a bool is contained
369 boost::optional<int> boi(3);
370 EXPECT_TRUE(boi < 5);
371 EXPECT_TRUE(boi <= 4);
372 EXPECT_TRUE(boi == 3);
373 EXPECT_TRUE(boi != 2);
374 EXPECT_TRUE(boi >= 1);
375 EXPECT_TRUE(boi > 0);
376 EXPECT_TRUE(1 < boi);
377 EXPECT_TRUE(2 <= boi);
378 EXPECT_TRUE(3 == boi);
379 EXPECT_TRUE(4 != boi);
380 EXPECT_TRUE(5 >= boi);
381 EXPECT_TRUE(6 > boi);
383 boost::optional<bool> bob(false);
384 EXPECT_TRUE((bool)bob);
385 EXPECT_TRUE(bob == false); // well that was confusing
386 EXPECT_FALSE(bob != false);
389 TEST(Optional, Conversions) {
390 Optional<bool> mbool;
391 Optional<short> mshort;
392 Optional<char*> mstr;
395 //These don't compile
404 // intended explicit operator bool, for if (opt).
408 // Truthy tests work and are not ambiguous
409 if (mbool && mshort && mstr && mint) { // only checks not-empty
410 if (*mbool && *mshort && *mstr && *mint) { // only checks value
416 EXPECT_TRUE(bool(mbool));
417 EXPECT_FALSE(*mbool);
420 EXPECT_TRUE(bool(mbool));
424 EXPECT_FALSE(bool(mbool));
426 // No conversion allowed; does not compile
427 // EXPECT_TRUE(mbool == false);
430 TEST(Optional, Pointee) {
432 EXPECT_FALSE(get_pointer(x));
434 EXPECT_TRUE(get_pointer(x));
436 EXPECT_TRUE(*x == 2);
438 EXPECT_FALSE(get_pointer(x));
441 TEST(Optional, MakeOptional) {
442 // const L-value version
443 const std::string s("abc");
444 auto optStr = make_optional(s);
445 ASSERT_TRUE(optStr.hasValue());
446 EXPECT_EQ(*optStr, "abc");
449 EXPECT_EQ(*optStr, "cde");
452 std::string s2("abc");
453 auto optStr2 = make_optional(s2);
454 ASSERT_TRUE(optStr2.hasValue());
455 EXPECT_EQ(*optStr2, "abc");
457 // it's vital to check that s2 wasn't clobbered
458 EXPECT_EQ(s2, "abc");
460 // L-value reference version
462 auto optStr3 = make_optional(s3);
463 ASSERT_TRUE(optStr3.hasValue());
464 EXPECT_EQ(*optStr3, "abc");
466 EXPECT_EQ(s3, "abc");
468 // R-value ref version
469 unique_ptr<int> pInt(new int(3));
470 auto optIntPtr = make_optional(std::move(pInt));
471 EXPECT_TRUE(pInt.get() == nullptr);
472 ASSERT_TRUE(optIntPtr.hasValue());
473 EXPECT_EQ(**optIntPtr, 3);
477 # pragma clang diagnostic push
478 # if __clang_major__ > 3 || __clang_minor__ >= 6
479 # pragma clang diagnostic ignored "-Wself-move"
483 TEST(Optional, SelfAssignment) {
484 Optional<int> a = 42;
486 ASSERT_TRUE(a.hasValue() && a.value() == 42);
488 Optional<int> b = 23333333;
490 ASSERT_TRUE(b.hasValue() && b.value() == 23333333);
494 #pragma clang diagnostic pop
497 class ContainsOptional {
499 ContainsOptional() { }
500 explicit ContainsOptional(int x) : opt_(x) { }
501 bool hasValue() const { return opt_.hasValue(); }
502 int value() const { return opt_.value(); }
504 ContainsOptional(const ContainsOptional &other) = default;
505 ContainsOptional& operator=(const ContainsOptional &other) = default;
506 ContainsOptional(ContainsOptional &&other) = default;
507 ContainsOptional& operator=(ContainsOptional &&other) = default;
514 * Test that a class containing an Optional can be copy and move assigned.
515 * This was broken under gcc 4.7 until assignment operators were explicitly
518 TEST(Optional, AssignmentContained) {
520 ContainsOptional source(5), target;
522 EXPECT_TRUE(target.hasValue());
523 EXPECT_EQ(5, target.value());
527 ContainsOptional source(5), target;
528 target = std::move(source);
529 EXPECT_TRUE(target.hasValue());
530 EXPECT_EQ(5, target.value());
531 EXPECT_FALSE(source.hasValue());
535 ContainsOptional opt_uninit, target(10);
537 EXPECT_FALSE(target.hasValue());
541 TEST(Optional, Exceptions) {
543 EXPECT_THROW(empty.value(), OptionalEmptyException);
546 TEST(Optional, NoThrowDefaultConstructible) {
547 EXPECT_TRUE(std::is_nothrow_default_constructible<Optional<bool>>::value);