| // Copyright 2017 The Abseil Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "absl/utility/utility.h" |
| |
| #include <sstream> |
| #include <string> |
| #include <tuple> |
| #include <type_traits> |
| #include <vector> |
| |
| #include "gmock/gmock.h" |
| #include "gtest/gtest.h" |
| #include "absl/base/attributes.h" |
| #include "absl/memory/memory.h" |
| #include "absl/strings/str_cat.h" |
| |
| namespace { |
| |
| #ifdef _MSC_VER |
| // Warnings for unused variables in this test are false positives. On other |
| // platforms, they are suppressed by ABSL_ATTRIBUTE_UNUSED, but that doesn't |
| // work on MSVC. |
| // Both the unused variables and the name length warnings are due to calls |
| // to absl::make_index_sequence with very large values, creating very long type |
| // names. The resulting warnings are so long they make build output unreadable. |
| #pragma warning( push ) |
| #pragma warning( disable : 4503 ) // decorated name length exceeded |
| #pragma warning( disable : 4101 ) // unreferenced local variable |
| #endif // _MSC_VER |
| |
| using ::testing::ElementsAre; |
| using ::testing::Pointee; |
| using ::testing::StaticAssertTypeEq; |
| |
| TEST(IntegerSequenceTest, ValueType) { |
| StaticAssertTypeEq<int, absl::integer_sequence<int>::value_type>(); |
| StaticAssertTypeEq<char, absl::integer_sequence<char>::value_type>(); |
| } |
| |
| TEST(IntegerSequenceTest, Size) { |
| EXPECT_EQ(0, (absl::integer_sequence<int>::size())); |
| EXPECT_EQ(1, (absl::integer_sequence<int, 0>::size())); |
| EXPECT_EQ(1, (absl::integer_sequence<int, 1>::size())); |
| EXPECT_EQ(2, (absl::integer_sequence<int, 1, 2>::size())); |
| EXPECT_EQ(3, (absl::integer_sequence<int, 0, 1, 2>::size())); |
| EXPECT_EQ(3, (absl::integer_sequence<int, -123, 123, 456>::size())); |
| constexpr size_t sz = absl::integer_sequence<int, 0, 1>::size(); |
| EXPECT_EQ(2, sz); |
| } |
| |
| TEST(IntegerSequenceTest, MakeIndexSequence) { |
| StaticAssertTypeEq<absl::index_sequence<>, absl::make_index_sequence<0>>(); |
| StaticAssertTypeEq<absl::index_sequence<0>, absl::make_index_sequence<1>>(); |
| StaticAssertTypeEq<absl::index_sequence<0, 1>, |
| absl::make_index_sequence<2>>(); |
| StaticAssertTypeEq<absl::index_sequence<0, 1, 2>, |
| absl::make_index_sequence<3>>(); |
| } |
| |
| TEST(IntegerSequenceTest, MakeIntegerSequence) { |
| StaticAssertTypeEq<absl::integer_sequence<int>, |
| absl::make_integer_sequence<int, 0>>(); |
| StaticAssertTypeEq<absl::integer_sequence<int, 0>, |
| absl::make_integer_sequence<int, 1>>(); |
| StaticAssertTypeEq<absl::integer_sequence<int, 0, 1>, |
| absl::make_integer_sequence<int, 2>>(); |
| StaticAssertTypeEq<absl::integer_sequence<int, 0, 1, 2>, |
| absl::make_integer_sequence<int, 3>>(); |
| } |
| |
| template <typename... Ts> |
| class Counter {}; |
| |
| template <size_t... Is> |
| void CountAll(absl::index_sequence<Is...>) { |
| // We only need an alias here, but instantiate a variable to silence warnings |
| // for unused typedefs in some compilers. |
| ABSL_ATTRIBUTE_UNUSED Counter<absl::make_index_sequence<Is>...> seq; |
| } |
| |
| // This test verifies that absl::make_index_sequence can handle large arguments |
| // without blowing up template instantiation stack, going OOM or taking forever |
| // to compile (there is hard 15 minutes limit imposed by forge). |
| TEST(IntegerSequenceTest, MakeIndexSequencePerformance) { |
| // O(log N) template instantiations. |
| // We only need an alias here, but instantiate a variable to silence warnings |
| // for unused typedefs in some compilers. |
| ABSL_ATTRIBUTE_UNUSED absl::make_index_sequence<(1 << 16) - 1> seq; |
| // O(N) template instantiations. |
| CountAll(absl::make_index_sequence<(1 << 8) - 1>()); |
| } |
| |
| template <typename F, typename Tup, size_t... Is> |
| auto ApplyFromTupleImpl(F f, const Tup& tup, absl::index_sequence<Is...>) |
| -> decltype(f(std::get<Is>(tup)...)) { |
| return f(std::get<Is>(tup)...); |
| } |
| |
| template <typename Tup> |
| using TupIdxSeq = absl::make_index_sequence<std::tuple_size<Tup>::value>; |
| |
| template <typename F, typename Tup> |
| auto ApplyFromTuple(F f, const Tup& tup) |
| -> decltype(ApplyFromTupleImpl(f, tup, TupIdxSeq<Tup>{})) { |
| return ApplyFromTupleImpl(f, tup, TupIdxSeq<Tup>{}); |
| } |
| |
| template <typename T> |
| std::string Fmt(const T& x) { |
| std::ostringstream os; |
| os << x; |
| return os.str(); |
| } |
| |
| struct PoorStrCat { |
| template <typename... Args> |
| std::string operator()(const Args&... args) const { |
| std::string r; |
| for (const auto& e : {Fmt(args)...}) r += e; |
| return r; |
| } |
| }; |
| |
| template <typename Tup, size_t... Is> |
| std::vector<std::string> TupStringVecImpl(const Tup& tup, |
| absl::index_sequence<Is...>) { |
| return {Fmt(std::get<Is>(tup))...}; |
| } |
| |
| template <typename... Ts> |
| std::vector<std::string> TupStringVec(const std::tuple<Ts...>& tup) { |
| return TupStringVecImpl(tup, absl::index_sequence_for<Ts...>()); |
| } |
| |
| TEST(MakeIndexSequenceTest, ApplyFromTupleExample) { |
| PoorStrCat f{}; |
| EXPECT_EQ("12abc3.14", f(12, "abc", 3.14)); |
| EXPECT_EQ("12abc3.14", ApplyFromTuple(f, std::make_tuple(12, "abc", 3.14))); |
| } |
| |
| TEST(IndexSequenceForTest, Basic) { |
| StaticAssertTypeEq<absl::index_sequence<>, absl::index_sequence_for<>>(); |
| StaticAssertTypeEq<absl::index_sequence<0>, absl::index_sequence_for<int>>(); |
| StaticAssertTypeEq<absl::index_sequence<0, 1, 2, 3>, |
| absl::index_sequence_for<int, void, char, int>>(); |
| } |
| |
| TEST(IndexSequenceForTest, Example) { |
| EXPECT_THAT(TupStringVec(std::make_tuple(12, "abc", 3.14)), |
| ElementsAre("12", "abc", "3.14")); |
| } |
| |
| int Function(int a, int b) { return a - b; } |
| |
| int Sink(std::unique_ptr<int> p) { return *p; } |
| |
| std::unique_ptr<int> Factory(int n) { return absl::make_unique<int>(n); } |
| |
| void NoOp() {} |
| |
| struct ConstFunctor { |
| int operator()(int a, int b) const { return a - b; } |
| }; |
| |
| struct MutableFunctor { |
| int operator()(int a, int b) { return a - b; } |
| }; |
| |
| struct EphemeralFunctor { |
| EphemeralFunctor() {} |
| EphemeralFunctor(const EphemeralFunctor&) {} |
| EphemeralFunctor(EphemeralFunctor&&) {} |
| int operator()(int a, int b) && { return a - b; } |
| }; |
| |
| struct OverloadedFunctor { |
| OverloadedFunctor() {} |
| OverloadedFunctor(const OverloadedFunctor&) {} |
| OverloadedFunctor(OverloadedFunctor&&) {} |
| template <typename... Args> |
| std::string operator()(const Args&... args) & { |
| return absl::StrCat("&", args...); |
| } |
| template <typename... Args> |
| std::string operator()(const Args&... args) const& { |
| return absl::StrCat("const&", args...); |
| } |
| template <typename... Args> |
| std::string operator()(const Args&... args) && { |
| return absl::StrCat("&&", args...); |
| } |
| }; |
| |
| struct Class { |
| int Method(int a, int b) { return a - b; } |
| int ConstMethod(int a, int b) const { return a - b; } |
| |
| int member; |
| }; |
| |
| struct FlipFlop { |
| int ConstMethod() const { return member; } |
| FlipFlop operator*() const { return {-member}; } |
| |
| int member; |
| }; |
| |
| TEST(ApplyTest, Function) { |
| EXPECT_EQ(1, absl::apply(Function, std::make_tuple(3, 2))); |
| EXPECT_EQ(1, absl::apply(&Function, std::make_tuple(3, 2))); |
| } |
| |
| TEST(ApplyTest, NonCopyableArgument) { |
| EXPECT_EQ(42, absl::apply(Sink, std::make_tuple(absl::make_unique<int>(42)))); |
| } |
| |
| TEST(ApplyTest, NonCopyableResult) { |
| EXPECT_THAT(absl::apply(Factory, std::make_tuple(42)), |
| ::testing::Pointee(42)); |
| } |
| |
| TEST(ApplyTest, VoidResult) { absl::apply(NoOp, std::tuple<>()); } |
| |
| TEST(ApplyTest, ConstFunctor) { |
| EXPECT_EQ(1, absl::apply(ConstFunctor(), std::make_tuple(3, 2))); |
| } |
| |
| TEST(ApplyTest, MutableFunctor) { |
| MutableFunctor f; |
| EXPECT_EQ(1, absl::apply(f, std::make_tuple(3, 2))); |
| EXPECT_EQ(1, absl::apply(MutableFunctor(), std::make_tuple(3, 2))); |
| } |
| TEST(ApplyTest, EphemeralFunctor) { |
| EphemeralFunctor f; |
| EXPECT_EQ(1, absl::apply(std::move(f), std::make_tuple(3, 2))); |
| EXPECT_EQ(1, absl::apply(EphemeralFunctor(), std::make_tuple(3, 2))); |
| } |
| TEST(ApplyTest, OverloadedFunctor) { |
| OverloadedFunctor f; |
| const OverloadedFunctor& cf = f; |
| |
| EXPECT_EQ("&", absl::apply(f, std::tuple<>{})); |
| EXPECT_EQ("& 42", absl::apply(f, std::make_tuple(" 42"))); |
| |
| EXPECT_EQ("const&", absl::apply(cf, std::tuple<>{})); |
| EXPECT_EQ("const& 42", absl::apply(cf, std::make_tuple(" 42"))); |
| |
| EXPECT_EQ("&&", absl::apply(std::move(f), std::tuple<>{})); |
| OverloadedFunctor f2; |
| EXPECT_EQ("&& 42", absl::apply(std::move(f2), std::make_tuple(" 42"))); |
| } |
| |
| TEST(ApplyTest, ReferenceWrapper) { |
| ConstFunctor cf; |
| MutableFunctor mf; |
| EXPECT_EQ(1, absl::apply(std::cref(cf), std::make_tuple(3, 2))); |
| EXPECT_EQ(1, absl::apply(std::ref(cf), std::make_tuple(3, 2))); |
| EXPECT_EQ(1, absl::apply(std::ref(mf), std::make_tuple(3, 2))); |
| } |
| |
| TEST(ApplyTest, MemberFunction) { |
| std::unique_ptr<Class> p(new Class); |
| std::unique_ptr<const Class> cp(new Class); |
| EXPECT_EQ( |
| 1, absl::apply(&Class::Method, |
| std::tuple<std::unique_ptr<Class>&, int, int>(p, 3, 2))); |
| EXPECT_EQ(1, absl::apply(&Class::Method, |
| std::tuple<Class*, int, int>(p.get(), 3, 2))); |
| EXPECT_EQ( |
| 1, absl::apply(&Class::Method, std::tuple<Class&, int, int>(*p, 3, 2))); |
| |
| EXPECT_EQ( |
| 1, absl::apply(&Class::ConstMethod, |
| std::tuple<std::unique_ptr<Class>&, int, int>(p, 3, 2))); |
| EXPECT_EQ(1, absl::apply(&Class::ConstMethod, |
| std::tuple<Class*, int, int>(p.get(), 3, 2))); |
| EXPECT_EQ(1, absl::apply(&Class::ConstMethod, |
| std::tuple<Class&, int, int>(*p, 3, 2))); |
| |
| EXPECT_EQ(1, absl::apply(&Class::ConstMethod, |
| std::tuple<std::unique_ptr<const Class>&, int, int>( |
| cp, 3, 2))); |
| EXPECT_EQ(1, absl::apply(&Class::ConstMethod, |
| std::tuple<const Class*, int, int>(cp.get(), 3, 2))); |
| EXPECT_EQ(1, absl::apply(&Class::ConstMethod, |
| std::tuple<const Class&, int, int>(*cp, 3, 2))); |
| |
| EXPECT_EQ(1, absl::apply(&Class::Method, |
| std::make_tuple(absl::make_unique<Class>(), 3, 2))); |
| EXPECT_EQ(1, absl::apply(&Class::ConstMethod, |
| std::make_tuple(absl::make_unique<Class>(), 3, 2))); |
| EXPECT_EQ( |
| 1, absl::apply(&Class::ConstMethod, |
| std::make_tuple(absl::make_unique<const Class>(), 3, 2))); |
| } |
| |
| TEST(ApplyTest, DataMember) { |
| std::unique_ptr<Class> p(new Class{42}); |
| std::unique_ptr<const Class> cp(new Class{42}); |
| EXPECT_EQ( |
| 42, absl::apply(&Class::member, std::tuple<std::unique_ptr<Class>&>(p))); |
| EXPECT_EQ(42, absl::apply(&Class::member, std::tuple<Class&>(*p))); |
| EXPECT_EQ(42, absl::apply(&Class::member, std::tuple<Class*>(p.get()))); |
| |
| absl::apply(&Class::member, std::tuple<std::unique_ptr<Class>&>(p)) = 42; |
| absl::apply(&Class::member, std::tuple<Class*>(p.get())) = 42; |
| absl::apply(&Class::member, std::tuple<Class&>(*p)) = 42; |
| |
| EXPECT_EQ(42, absl::apply(&Class::member, |
| std::tuple<std::unique_ptr<const Class>&>(cp))); |
| EXPECT_EQ(42, absl::apply(&Class::member, std::tuple<const Class&>(*cp))); |
| EXPECT_EQ(42, |
| absl::apply(&Class::member, std::tuple<const Class*>(cp.get()))); |
| } |
| |
| TEST(ApplyTest, FlipFlop) { |
| FlipFlop obj = {42}; |
| // This call could resolve to (obj.*&FlipFlop::ConstMethod)() or |
| // ((*obj).*&FlipFlop::ConstMethod)(). We verify that it's the former. |
| EXPECT_EQ(42, absl::apply(&FlipFlop::ConstMethod, std::make_tuple(obj))); |
| EXPECT_EQ(42, absl::apply(&FlipFlop::member, std::make_tuple(obj))); |
| } |
| |
| TEST(ExchangeTest, MoveOnly) { |
| auto a = Factory(1); |
| EXPECT_EQ(1, *a); |
| auto b = absl::exchange(a, Factory(2)); |
| EXPECT_EQ(2, *a); |
| EXPECT_EQ(1, *b); |
| } |
| |
| } // namespace |
| |