// Copyright 2018 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/container/internal/compressed_tuple.h"
#include <memory>
#include <set>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "absl/container/internal/test_instance_tracker.h"
#include "absl/memory/memory.h"
#include "absl/types/any.h"
#include "absl/types/optional.h"
#include "absl/utility/utility.h"
// These are declared at global scope purely so that error messages
// are smaller and easier to understand.
enum class CallType { kMutableRef, kConstRef, kMutableMove, kConstMove };
template <int>
struct Empty {
constexpr CallType value() & { return CallType::kMutableRef; }
constexpr CallType value() const& { return CallType::kConstRef; }
constexpr CallType value() && { return CallType::kMutableMove; }
constexpr CallType value() const&& { return CallType::kConstMove; }
};
// Unconditionally return an lvalue reference to `t`.
template <typename T>
constexpr T& AsLValue(T&& t) {
return t;
}
template <typename T>
struct NotEmpty {
T value;
};
template <typename T, typename U>
struct TwoValues {
T value1;
U value2;
};
namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
namespace {
using absl::test_internal::CopyableMovableInstance;
using absl::test_internal::InstanceTracker;
using ::testing::Each;
TEST(CompressedTupleTest, Sizeof) {
EXPECT_EQ(sizeof(int), sizeof(CompressedTuple<int>));
EXPECT_EQ(sizeof(int), sizeof(CompressedTuple<int, Empty<0>>));
EXPECT_EQ(sizeof(int), sizeof(CompressedTuple<int, Empty<0>, Empty<1>>));
EXPECT_EQ(sizeof(int),
sizeof(CompressedTuple<int, Empty<0>, Empty<1>, Empty<2>>));
EXPECT_EQ(sizeof(TwoValues<int, double>),
sizeof(CompressedTuple<int, NotEmpty<double>>));
EXPECT_EQ(sizeof(TwoValues<int, double>),
sizeof(CompressedTuple<int, Empty<0>, NotEmpty<double>>));
EXPECT_EQ(sizeof(TwoValues<int, double>),
sizeof(CompressedTuple<int, Empty<0>, NotEmpty<double>, Empty<1>>));
}
TEST(CompressedTupleTest, PointerToEmpty) {
auto to_void_ptrs = [](const auto&... objs) {
return std::vector<const void*>{static_cast<const void*>(&objs)...};
};
{
using Tuple = CompressedTuple<int, Empty<0>>;
EXPECT_EQ(sizeof(int), sizeof(Tuple));
Tuple t;
EXPECT_THAT(to_void_ptrs(t.get<1>()), Each(&t));
}
{
using Tuple = CompressedTuple<int, Empty<0>, Empty<1>>;
EXPECT_EQ(sizeof(int), sizeof(Tuple));
Tuple t;
EXPECT_THAT(to_void_ptrs(t.get<1>(), t.get<2>()), Each(&t));
}
{
using Tuple = CompressedTuple<int, Empty<0>, Empty<1>, Empty<2>>;
EXPECT_EQ(sizeof(int), sizeof(Tuple));
Tuple t;
EXPECT_THAT(to_void_ptrs(t.get<1>(), t.get<2>(), t.get<3>()), Each(&t));
}
}
TEST(CompressedTupleTest, OneMoveOnRValueConstructionTemp) {
InstanceTracker tracker;
CompressedTuple<CopyableMovableInstance> x1(CopyableMovableInstance(1));
EXPECT_EQ(tracker.instances(), 1);
EXPECT_EQ(tracker.copies(), 0);
EXPECT_LE(tracker.moves(), 1);
EXPECT_EQ(x1.get<0>().value(), 1);
}
TEST(CompressedTupleTest, OneMoveOnRValueConstructionMove) {
InstanceTracker tracker;
CopyableMovableInstance i1(1);
CompressedTuple<CopyableMovableInstance> x1(std::move(i1));
EXPECT_EQ(tracker.instances(), 2);
EXPECT_EQ(tracker.copies(), 0);
EXPECT_LE(tracker.moves(), 1);
EXPECT_EQ(x1.get<0>().value(), 1);
}
TEST(CompressedTupleTest, OneMoveOnRValueConstructionMixedTypes) {
InstanceTracker tracker;
CopyableMovableInstance i1(1);
CopyableMovableInstance i2(2);
Empty<0> empty;
CompressedTuple<CopyableMovableInstance, CopyableMovableInstance&, Empty<0>>
x1(std::move(i1), i2, empty);
EXPECT_EQ(x1.get<0>().value(), 1);
EXPECT_EQ(x1.get<1>().value(), 2);
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 1);
}
struct IncompleteType;
CompressedTuple<CopyableMovableInstance, IncompleteType&, Empty<0>>
MakeWithIncomplete(CopyableMovableInstance i1,
IncompleteType& t, // NOLINT
Empty<0> empty) {
return CompressedTuple<CopyableMovableInstance, IncompleteType&, Empty<0>>{
std::move(i1), t, empty};
}
struct IncompleteType {};
TEST(CompressedTupleTest, OneMoveOnRValueConstructionWithIncompleteType) {
InstanceTracker tracker;
CopyableMovableInstance i1(1);
Empty<0> empty;
struct DerivedType : IncompleteType {int value = 0;};
DerivedType fd;
fd.value = 7;
CompressedTuple<CopyableMovableInstance, IncompleteType&, Empty<0>> x1 =
MakeWithIncomplete(std::move(i1), fd, empty);
EXPECT_EQ(x1.get<0>().value(), 1);
EXPECT_EQ(static_cast<DerivedType&>(x1.get<1>()).value, 7);
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 2);
}
TEST(CompressedTupleTest,
OneMoveOnRValueConstructionMixedTypes_BraceInitPoisonPillExpected) {
InstanceTracker tracker;
CopyableMovableInstance i1(1);
CopyableMovableInstance i2(2);
CompressedTuple<CopyableMovableInstance, CopyableMovableInstance&, Empty<0>>
x1(std::move(i1), i2, {}); // NOLINT
EXPECT_EQ(x1.get<0>().value(), 1);
EXPECT_EQ(x1.get<1>().value(), 2);
EXPECT_EQ(tracker.instances(), 3);
// We are forced into the `const Ts&...` constructor (invoking copies)
// because we need it to deduce the type of `{}`.
// std::tuple also has this behavior.
// Note, this test is proof that this is expected behavior, but it is not
// _desired_ behavior.
EXPECT_EQ(tracker.copies(), 1);
EXPECT_EQ(tracker.moves(), 0);
}
TEST(CompressedTupleTest, OneCopyOnLValueConstruction) {
InstanceTracker tracker;
CopyableMovableInstance i1(1);
CompressedTuple<CopyableMovableInstance> x1(i1);
EXPECT_EQ(tracker.copies(), 1);
EXPECT_EQ(tracker.moves(), 0);
tracker.ResetCopiesMovesSwaps();
CopyableMovableInstance i2(2);
const CopyableMovableInstance& i2_ref = i2;
CompressedTuple<CopyableMovableInstance> x2(i2_ref);
EXPECT_EQ(tracker.copies(), 1);
EXPECT_EQ(tracker.moves(), 0);
}
TEST(CompressedTupleTest, OneMoveOnRValueAccess) {
InstanceTracker tracker;
CopyableMovableInstance i1(1);
CompressedTuple<CopyableMovableInstance> x(std::move(i1));
tracker.ResetCopiesMovesSwaps();
CopyableMovableInstance i2 = std::move(x).get<0>();
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 1);
}
TEST(CompressedTupleTest, OneCopyOnLValueAccess) {
InstanceTracker tracker;
CompressedTuple<CopyableMovableInstance> x(CopyableMovableInstance(0));
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 1);
CopyableMovableInstance t = x.get<0>();
EXPECT_EQ(tracker.copies(), 1);
EXPECT_EQ(tracker.moves(), 1);
}
TEST(CompressedTupleTest, ZeroCopyOnRefAccess) {
InstanceTracker tracker;
CompressedTuple<CopyableMovableInstance> x(CopyableMovableInstance(0));
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 1);
CopyableMovableInstance& t1 = x.get<0>();
const CopyableMovableInstance& t2 = x.get<0>();
EXPECT_EQ(tracker.copies(), 0);
EXPECT_EQ(tracker.moves(), 1);
EXPECT_EQ(t1.value(), 0);
EXPECT_EQ(t2.value(), 0);
}
TEST(CompressedTupleTest, Access) {
struct S {
std::string x;
};
CompressedTuple<int, Empty<0>, S> x(7, {}, S{"ABC"});
EXPECT_EQ(sizeof(x), sizeof(TwoValues<int, S>));
EXPECT_EQ(7, x.get<0>());
EXPECT_EQ("ABC", x.get<2>().x);
}
TEST(CompressedTupleTest, NonClasses) {
CompressedTuple<int, const char*> x(7, "ABC");
EXPECT_EQ(7, x.get<0>());
EXPECT_STREQ("ABC", x.get<1>());
}
TEST(CompressedTupleTest, MixClassAndNonClass) {
CompressedTuple<int, const char*, Empty<0>, NotEmpty<double>> x(7, "ABC", {},
{1.25});
struct Mock {
int v;
const char* p;
double d;
};
EXPECT_EQ(sizeof(x), sizeof(Mock));
EXPECT_EQ(7, x.get<0>());
EXPECT_STREQ("ABC", x.get<1>());
EXPECT_EQ(1.25, x.get<3>().value);
}
TEST(CompressedTupleTest, Nested) {
CompressedTuple<int, CompressedTuple<int>,
CompressedTuple<int, CompressedTuple<int>>>
x(1, CompressedTuple<int>(2),
CompressedTuple<int, CompressedTuple<int>>(3, CompressedTuple<int>(4)));
EXPECT_EQ(1, x.get<0>());
EXPECT_EQ(2, x.get<1>().get<0>());
EXPECT_EQ(3, x.get<2>().get<0>());
EXPECT_EQ(4, x.get<2>().get<1>().get<0>());
CompressedTuple<Empty<0>, Empty<0>,
CompressedTuple<Empty<0>, CompressedTuple<Empty<0>>>>
y;
std::set<Empty<0>*> empties{&y.get<0>(), &y.get<1>(), &y.get<2>().get<0>(),
&y.get<2>().get<1>().get<0>()};
#ifdef _MSC_VER
// MSVC has a bug where many instances of the same base class are layed out in
// the same address when using __declspec(empty_bases).
// This will be fixed in a future version of MSVC.
int expected = 1;
#else
int expected = 4;
#endif
EXPECT_EQ(expected, sizeof(y));
EXPECT_EQ(expected, empties.size());
EXPECT_EQ(sizeof(y), sizeof(Empty<0>) * empties.size());
EXPECT_EQ(4 * sizeof(char),
sizeof(CompressedTuple<CompressedTuple<char, char>,
CompressedTuple<char, char>>));
EXPECT_TRUE((std::is_empty<CompressedTuple<Empty<0>, Empty<1>>>::value));
// Make sure everything still works when things are nested.
struct CT_Empty : CompressedTuple<Empty<0>> {};
CompressedTuple<Empty<0>, CT_Empty> nested_empty;
auto contained = nested_empty.get<0>();
auto nested = nested_empty.get<1>().get<0>();
EXPECT_TRUE((std::is_same<decltype(contained), decltype(nested)>::value));
}
TEST(CompressedTupleTest, Reference) {
int i = 7;
std::string s = "Very long string that goes in the heap";
CompressedTuple<int, int&, std::string, std::string&> x(i, i, s, s);
// Sanity check. We should have not moved from `s`
EXPECT_EQ(s, "Very long string that goes in the heap");
EXPECT_EQ(x.get<0>(), x.get<1>());
EXPECT_NE(&x.get<0>(), &x.get<1>());
EXPECT_EQ(&x.get<1>(), &i);
EXPECT_EQ(x.get<2>(), x.get<3>());
EXPECT_NE(&x.get<2>(), &x.get<3>());
EXPECT_EQ(&x.get<3>(), &s);
}
TEST(CompressedTupleTest, NoElements) {
CompressedTuple<> x;
static_cast<void>(x); // Silence -Wunused-variable.
EXPECT_TRUE(std::is_empty<CompressedTuple<>>::value);
}
TEST(CompressedTupleTest, MoveOnlyElements) {
CompressedTuple<std::unique_ptr<std::string>> str_tup(
absl::make_unique<std::string>("str"));
CompressedTuple<CompressedTuple<std::unique_ptr<std::string>>,
std::unique_ptr<int>>
x(std::move(str_tup), absl::make_unique<int>(5));
EXPECT_EQ(*x.get<0>().get<0>(), "str");
EXPECT_EQ(*x.get<1>(), 5);
std::unique_ptr<std::string> x0 = std::move(x.get<0>()).get<0>();
std::unique_ptr<int> x1 = std::move(x).get<1>();
EXPECT_EQ(*x0, "str");
EXPECT_EQ(*x1, 5);
}
TEST(CompressedTupleTest, MoveConstructionMoveOnlyElements) {
CompressedTuple<std::unique_ptr<std::string>> base(
absl::make_unique<std::string>("str"));
EXPECT_EQ(*base.get<0>(), "str");
CompressedTuple<std::unique_ptr<std::string>> copy(std::move(base));
EXPECT_EQ(*copy.get<0>(), "str");
}
TEST(CompressedTupleTest, AnyElements) {
any a(std::string("str"));
CompressedTuple<any, any&> x(any(5), a);
EXPECT_EQ(absl::any_cast<int>(x.get<0>()), 5);
EXPECT_EQ(absl::any_cast<std::string>(x.get<1>()), "str");
a = 0.5f;
EXPECT_EQ(absl::any_cast<float>(x.get<1>()), 0.5);
}
TEST(CompressedTupleTest, Constexpr) {
struct NonTrivialStruct {
constexpr NonTrivialStruct() = default;
constexpr int value() const { return v; }
int v = 5;
};
struct TrivialStruct {
TrivialStruct() = default;
constexpr int value() const { return v; }
int v;
};
using Tuple = CompressedTuple<int, double, CompressedTuple<int>, Empty<0>>;
constexpr int r0 =
AsLValue(Tuple(1, 0.75, CompressedTuple<int>(9), {})).get<0>();
constexpr double r1 =
AsLValue(Tuple(1, 0.75, CompressedTuple<int>(9), {})).get<1>();
constexpr int r2 =
AsLValue(Tuple(1, 0.75, CompressedTuple<int>(9), {})).get<2>().get<0>();
constexpr CallType r3 =
AsLValue(Tuple(1, 0.75, CompressedTuple<int>(9), {})).get<3>().value();
EXPECT_EQ(r0, 1);
EXPECT_EQ(r1, 0.75);
EXPECT_EQ(r2, 9);
EXPECT_EQ(r3, CallType::kMutableRef);
constexpr Tuple x(7, 1.25, CompressedTuple<int>(5), {});
constexpr int x0 = x.get<0>();
constexpr double x1 = x.get<1>();
constexpr int x2 = x.get<2>().get<0>();
constexpr CallType x3 = x.get<3>().value();
EXPECT_EQ(x0, 7);
EXPECT_EQ(x1, 1.25);
EXPECT_EQ(x2, 5);
EXPECT_EQ(x3, CallType::kConstRef);
constexpr int m0 = Tuple(5, 0.25, CompressedTuple<int>(3), {}).get<0>();
constexpr double m1 = Tuple(5, 0.25, CompressedTuple<int>(3), {}).get<1>();
constexpr int m2 =
Tuple(5, 0.25, CompressedTuple<int>(3), {}).get<2>().get<0>();
constexpr CallType m3 =
Tuple(5, 0.25, CompressedTuple<int>(3), {}).get<3>().value();
EXPECT_EQ(m0, 5);
EXPECT_EQ(m1, 0.25);
EXPECT_EQ(m2, 3);
EXPECT_EQ(m3, CallType::kMutableMove);
constexpr CompressedTuple<Empty<0>, TrivialStruct, int> trivial = {};
constexpr CallType trivial0 = trivial.get<0>().value();
constexpr int trivial1 = trivial.get<1>().value();
constexpr int trivial2 = trivial.get<2>();
EXPECT_EQ(trivial0, CallType::kConstRef);
EXPECT_EQ(trivial1, 0);
EXPECT_EQ(trivial2, 0);
constexpr CompressedTuple<Empty<0>, NonTrivialStruct, absl::optional<int>>
non_trivial = {};
constexpr CallType non_trivial0 = non_trivial.get<0>().value();
constexpr int non_trivial1 = non_trivial.get<1>().value();
constexpr absl::optional<int> non_trivial2 = non_trivial.get<2>();
EXPECT_EQ(non_trivial0, CallType::kConstRef);
EXPECT_EQ(non_trivial1, 5);
EXPECT_EQ(non_trivial2, absl::nullopt);
static constexpr char data[] = "DEF";
constexpr CompressedTuple<const char*> z(data);
constexpr const char* z1 = z.get<0>();
EXPECT_EQ(std::string(z1), std::string(data));
#if defined(__clang__)
// An apparent bug in earlier versions of gcc claims these are ambiguous.
constexpr int x2m = std::move(x.get<2>()).get<0>();
constexpr CallType x3m = std::move(x).get<3>().value();
EXPECT_EQ(x2m, 5);
EXPECT_EQ(x3m, CallType::kConstMove);
#endif
}
#if defined(__clang__) || defined(__GNUC__)
TEST(CompressedTupleTest, EmptyFinalClass) {
struct S final {
int f() const { return 5; }
};
CompressedTuple<S> x;
EXPECT_EQ(x.get<0>().f(), 5);
}
#endif
// TODO(b/214288561): enable this test.
TEST(CompressedTupleTest, DISABLED_NestedEbo) {
struct Empty1 {};
struct Empty2 {};
CompressedTuple<Empty1, CompressedTuple<Empty2>, int> x;
CompressedTuple<Empty1, Empty2, int> y;
// Currently fails with sizeof(x) == 8, sizeof(y) == 4.
EXPECT_EQ(sizeof(x), sizeof(y));
}
} // namespace
} // namespace container_internal
ABSL_NAMESPACE_END
} // namespace absl
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