// 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/meta/type_traits.h"
#include <cstdint>
#include <string>
#include <type_traits>
#include <utility>
#include <vector>
#include "gtest/gtest.h"
namespace {
using ::testing::StaticAssertTypeEq;
template <class T, class U>
struct simple_pair {
T first;
U second;
};
struct Dummy {};
struct ReturnType {};
struct ConvertibleToReturnType {
operator ReturnType() const; // NOLINT
};
// Unique types used as parameter types for testing the detection idiom.
struct StructA {};
struct StructB {};
struct StructC {};
struct TypeWithBarFunction {
template <class T,
absl::enable_if_t<std::is_same<T&&, StructA&>::value, int> = 0>
ReturnType bar(T&&, const StructB&, StructC&&) &&; // NOLINT
};
struct TypeWithBarFunctionAndConvertibleReturnType {
template <class T,
absl::enable_if_t<std::is_same<T&&, StructA&>::value, int> = 0>
ConvertibleToReturnType bar(T&&, const StructB&, StructC&&) &&; // NOLINT
};
template <class Class, class... Ts>
using BarIsCallableImpl =
decltype(std::declval<Class>().bar(std::declval<Ts>()...));
template <class Class, class... T>
using BarIsCallable =
absl::type_traits_internal::is_detected<BarIsCallableImpl, Class, T...>;
template <class Class, class... T>
using BarIsCallableConv = absl::type_traits_internal::is_detected_convertible<
ReturnType, BarIsCallableImpl, Class, T...>;
// NOTE: Test of detail type_traits_internal::is_detected.
TEST(IsDetectedTest, BasicUsage) {
EXPECT_TRUE((BarIsCallable<TypeWithBarFunction, StructA&, const StructB&,
StructC>::value));
EXPECT_TRUE(
(BarIsCallable<TypeWithBarFunction, StructA&, StructB&, StructC>::value));
EXPECT_TRUE(
(BarIsCallable<TypeWithBarFunction, StructA&, StructB, StructC>::value));
EXPECT_FALSE((BarIsCallable<int, StructA&, const StructB&, StructC>::value));
EXPECT_FALSE((BarIsCallable<TypeWithBarFunction&, StructA&, const StructB&,
StructC>::value));
EXPECT_FALSE((BarIsCallable<TypeWithBarFunction, StructA, const StructB&,
StructC>::value));
}
// NOTE: Test of detail type_traits_internal::is_detected_convertible.
TEST(IsDetectedConvertibleTest, BasicUsage) {
EXPECT_TRUE((BarIsCallableConv<TypeWithBarFunction, StructA&, const StructB&,
StructC>::value));
EXPECT_TRUE((BarIsCallableConv<TypeWithBarFunction, StructA&, StructB&,
StructC>::value));
EXPECT_TRUE((BarIsCallableConv<TypeWithBarFunction, StructA&, StructB,
StructC>::value));
EXPECT_TRUE((BarIsCallableConv<TypeWithBarFunctionAndConvertibleReturnType,
StructA&, const StructB&, StructC>::value));
EXPECT_TRUE((BarIsCallableConv<TypeWithBarFunctionAndConvertibleReturnType,
StructA&, StructB&, StructC>::value));
EXPECT_TRUE((BarIsCallableConv<TypeWithBarFunctionAndConvertibleReturnType,
StructA&, StructB, StructC>::value));
EXPECT_FALSE(
(BarIsCallableConv<int, StructA&, const StructB&, StructC>::value));
EXPECT_FALSE((BarIsCallableConv<TypeWithBarFunction&, StructA&,
const StructB&, StructC>::value));
EXPECT_FALSE((BarIsCallableConv<TypeWithBarFunction, StructA, const StructB&,
StructC>::value));
EXPECT_FALSE((BarIsCallableConv<TypeWithBarFunctionAndConvertibleReturnType&,
StructA&, const StructB&, StructC>::value));
EXPECT_FALSE((BarIsCallableConv<TypeWithBarFunctionAndConvertibleReturnType,
StructA, const StructB&, StructC>::value));
}
TEST(VoidTTest, BasicUsage) {
StaticAssertTypeEq<void, absl::void_t<Dummy>>();
StaticAssertTypeEq<void, absl::void_t<Dummy, Dummy, Dummy>>();
}
TEST(ConjunctionTest, BasicBooleanLogic) {
EXPECT_TRUE(absl::conjunction<>::value);
EXPECT_TRUE(absl::conjunction<std::true_type>::value);
EXPECT_TRUE((absl::conjunction<std::true_type, std::true_type>::value));
EXPECT_FALSE((absl::conjunction<std::true_type, std::false_type>::value));
EXPECT_FALSE((absl::conjunction<std::false_type, std::true_type>::value));
EXPECT_FALSE((absl::conjunction<std::false_type, std::false_type>::value));
}
struct MyTrueType {
static constexpr bool value = true;
};
struct MyFalseType {
static constexpr bool value = false;
};
TEST(ConjunctionTest, ShortCircuiting) {
EXPECT_FALSE(
(absl::conjunction<std::true_type, std::false_type, Dummy>::value));
EXPECT_TRUE((std::is_base_of<MyFalseType,
absl::conjunction<std::true_type, MyFalseType,
std::false_type>>::value));
EXPECT_TRUE(
(std::is_base_of<MyTrueType,
absl::conjunction<std::true_type, MyTrueType>>::value));
}
TEST(DisjunctionTest, BasicBooleanLogic) {
EXPECT_FALSE(absl::disjunction<>::value);
EXPECT_FALSE(absl::disjunction<std::false_type>::value);
EXPECT_TRUE((absl::disjunction<std::true_type, std::true_type>::value));
EXPECT_TRUE((absl::disjunction<std::true_type, std::false_type>::value));
EXPECT_TRUE((absl::disjunction<std::false_type, std::true_type>::value));
EXPECT_FALSE((absl::disjunction<std::false_type, std::false_type>::value));
}
TEST(DisjunctionTest, ShortCircuiting) {
EXPECT_TRUE(
(absl::disjunction<std::false_type, std::true_type, Dummy>::value));
EXPECT_TRUE((
std::is_base_of<MyTrueType, absl::disjunction<std::false_type, MyTrueType,
std::true_type>>::value));
EXPECT_TRUE((
std::is_base_of<MyFalseType,
absl::disjunction<std::false_type, MyFalseType>>::value));
}
TEST(NegationTest, BasicBooleanLogic) {
EXPECT_FALSE(absl::negation<std::true_type>::value);
EXPECT_FALSE(absl::negation<MyTrueType>::value);
EXPECT_TRUE(absl::negation<std::false_type>::value);
EXPECT_TRUE(absl::negation<MyFalseType>::value);
}
// all member functions are trivial
class Trivial {
int n_;
};
struct TrivialDestructor {
~TrivialDestructor() = default;
};
struct NontrivialDestructor {
~NontrivialDestructor() {}
};
struct DeletedDestructor {
~DeletedDestructor() = delete;
};
class TrivialDefaultCtor {
public:
TrivialDefaultCtor() = default;
explicit TrivialDefaultCtor(int n) : n_(n) {}
private:
int n_;
};
class NontrivialDefaultCtor {
public:
NontrivialDefaultCtor() : n_(1) {}
private:
int n_;
};
class DeletedDefaultCtor {
public:
DeletedDefaultCtor() = delete;
explicit DeletedDefaultCtor(int n) : n_(n) {}
private:
int n_;
};
class TrivialCopyCtor {
public:
explicit TrivialCopyCtor(int n) : n_(n) {}
TrivialCopyCtor(const TrivialCopyCtor&) = default;
TrivialCopyCtor& operator=(const TrivialCopyCtor& t) {
n_ = t.n_;
return *this;
}
private:
int n_;
};
class NontrivialCopyCtor {
public:
explicit NontrivialCopyCtor(int n) : n_(n) {}
NontrivialCopyCtor(const NontrivialCopyCtor& t) : n_(t.n_) {}
NontrivialCopyCtor& operator=(const NontrivialCopyCtor&) = default;
private:
int n_;
};
class DeletedCopyCtor {
public:
explicit DeletedCopyCtor(int n) : n_(n) {}
DeletedCopyCtor(const DeletedCopyCtor&) = delete;
DeletedCopyCtor& operator=(const DeletedCopyCtor&) = default;
private:
int n_;
};
class TrivialCopyAssign {
public:
explicit TrivialCopyAssign(int n) : n_(n) {}
TrivialCopyAssign(const TrivialCopyAssign& t) : n_(t.n_) {}
TrivialCopyAssign& operator=(const TrivialCopyAssign& t) = default;
~TrivialCopyAssign() {} // can have nontrivial destructor
private:
int n_;
};
class NontrivialCopyAssign {
public:
explicit NontrivialCopyAssign(int n) : n_(n) {}
NontrivialCopyAssign(const NontrivialCopyAssign&) = default;
NontrivialCopyAssign& operator=(const NontrivialCopyAssign& t) {
n_ = t.n_;
return *this;
}
private:
int n_;
};
class DeletedCopyAssign {
public:
explicit DeletedCopyAssign(int n) : n_(n) {}
DeletedCopyAssign(const DeletedCopyAssign&) = default;
DeletedCopyAssign& operator=(const DeletedCopyAssign&) = delete;
private:
int n_;
};
struct NonCopyable {
NonCopyable() = default;
NonCopyable(const NonCopyable&) = delete;
NonCopyable& operator=(const NonCopyable&) = delete;
};
class Base {
public:
virtual ~Base() {}
};
// In GCC/Clang, std::is_trivially_constructible requires that the destructor is
// trivial. However, MSVC doesn't require that. This results in different
// behavior when checking is_trivially_constructible on any type with
// nontrivial destructor. Since absl::is_trivially_default_constructible and
// absl::is_trivially_copy_constructible both follows Clang/GCC's interpretation
// and check is_trivially_destructible, it results in inconsistency with
// std::is_trivially_xxx_constructible on MSVC. This macro is used to work
// around this issue in test. In practice, a trivially constructible type
// should also be trivially destructible.
// GCC bug 51452: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=51452
// LWG issue 2116: http://cplusplus.github.io/LWG/lwg-active.html#2116
#ifndef _MSC_VER
#define ABSL_TRIVIALLY_CONSTRUCTIBLE_VERIFY_TRIVIALLY_DESTRUCTIBLE 1
#endif
// Old versions of libc++, around Clang 3.5 to 3.6, consider deleted destructors
// as also being trivial. With the resolution of CWG 1928 and CWG 1734, this
// is no longer considered true and has thus been amended.
// Compiler Explorer: https://godbolt.org/g/zT59ZL
// CWG issue 1734: http://open-std.org/JTC1/SC22/WG21/docs/cwg_defects.html#1734
// CWG issue 1928: http://open-std.org/JTC1/SC22/WG21/docs/cwg_closed.html#1928
#if !defined(_LIBCPP_VERSION) || _LIBCPP_VERSION >= 3700
#define ABSL_TRIVIALLY_DESTRUCTIBLE_CONSIDER_DELETED_DESTRUCTOR_NOT_TRIVIAL 1
#endif
// As of the moment, GCC versions >5.1 have a problem compiling for
// std::is_trivially_default_constructible<NontrivialDestructor[10]>, where
// NontrivialDestructor is a struct with a custom nontrivial destructor. Note
// that this problem only occurs for arrays of a known size, so something like
// std::is_trivially_default_constructible<NontrivialDestructor[]> does not
// have any problems.
// Compiler Explorer: https://godbolt.org/g/dXRbdK
// GCC bug 83689: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83689
#if defined(__clang__) || defined(_MSC_VER) || \
(defined(__GNUC__) && __GNUC__ < 5)
#define ABSL_GCC_BUG_TRIVIALLY_CONSTRUCTIBLE_ON_ARRAY_OF_NONTRIVIAL 1
#endif
TEST(TypeTraitsTest, TestTrivialDestructor) {
// Verify that arithmetic types and pointers have trivial destructors.
EXPECT_TRUE(absl::is_trivially_destructible<bool>::value);
EXPECT_TRUE(absl::is_trivially_destructible<char>::value);
EXPECT_TRUE(absl::is_trivially_destructible<unsigned char>::value);
EXPECT_TRUE(absl::is_trivially_destructible<signed char>::value);
EXPECT_TRUE(absl::is_trivially_destructible<wchar_t>::value);
EXPECT_TRUE(absl::is_trivially_destructible<int>::value);
EXPECT_TRUE(absl::is_trivially_destructible<unsigned int>::value);
EXPECT_TRUE(absl::is_trivially_destructible<int16_t>::value);
EXPECT_TRUE(absl::is_trivially_destructible<uint16_t>::value);
EXPECT_TRUE(absl::is_trivially_destructible<int64_t>::value);
EXPECT_TRUE(absl::is_trivially_destructible<uint64_t>::value);
EXPECT_TRUE(absl::is_trivially_destructible<float>::value);
EXPECT_TRUE(absl::is_trivially_destructible<double>::value);
EXPECT_TRUE(absl::is_trivially_destructible<long double>::value);
EXPECT_TRUE(absl::is_trivially_destructible<std::string*>::value);
EXPECT_TRUE(absl::is_trivially_destructible<Trivial*>::value);
EXPECT_TRUE(absl::is_trivially_destructible<const std::string*>::value);
EXPECT_TRUE(absl::is_trivially_destructible<const Trivial*>::value);
EXPECT_TRUE(absl::is_trivially_destructible<std::string**>::value);
EXPECT_TRUE(absl::is_trivially_destructible<Trivial**>::value);
// classes with destructors
EXPECT_TRUE(absl::is_trivially_destructible<Trivial>::value);
EXPECT_TRUE(absl::is_trivially_destructible<TrivialDestructor>::value);
// Verify that types with a nontrivial or deleted destructor
// are marked as such.
EXPECT_FALSE(absl::is_trivially_destructible<NontrivialDestructor>::value);
#ifdef ABSL_TRIVIALLY_DESTRUCTIBLE_CONSIDER_DELETED_DESTRUCTOR_NOT_TRIVIAL
EXPECT_FALSE(absl::is_trivially_destructible<DeletedDestructor>::value);
#endif
// simple_pair of such types is trivial
EXPECT_TRUE((absl::is_trivially_destructible<simple_pair<int, int>>::value));
EXPECT_TRUE((absl::is_trivially_destructible<
simple_pair<Trivial, TrivialDestructor>>::value));
// Verify that types without trivial destructors are correctly marked as such.
EXPECT_FALSE(absl::is_trivially_destructible<std::string>::value);
EXPECT_FALSE(absl::is_trivially_destructible<std::vector<int>>::value);
// Verify that simple_pairs of types without trivial destructors
// are not marked as trivial.
EXPECT_FALSE((absl::is_trivially_destructible<
simple_pair<int, std::string>>::value));
EXPECT_FALSE((absl::is_trivially_destructible<
simple_pair<std::string, int>>::value));
// array of such types is trivial
using int10 = int[10];
EXPECT_TRUE(absl::is_trivially_destructible<int10>::value);
using Trivial10 = Trivial[10];
EXPECT_TRUE(absl::is_trivially_destructible<Trivial10>::value);
using TrivialDestructor10 = TrivialDestructor[10];
EXPECT_TRUE(absl::is_trivially_destructible<TrivialDestructor10>::value);
// Conversely, the opposite also holds.
using NontrivialDestructor10 = NontrivialDestructor[10];
EXPECT_FALSE(absl::is_trivially_destructible<NontrivialDestructor10>::value);
}
TEST(TypeTraitsTest, TestTrivialDefaultCtor) {
// arithmetic types and pointers have trivial default constructors.
EXPECT_TRUE(absl::is_trivially_default_constructible<bool>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<char>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<unsigned char>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<signed char>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<wchar_t>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<int>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<unsigned int>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<int16_t>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<uint16_t>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<int64_t>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<uint64_t>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<float>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<double>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<long double>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<std::string*>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<Trivial*>::value);
EXPECT_TRUE(
absl::is_trivially_default_constructible<const std::string*>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<const Trivial*>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<std::string**>::value);
EXPECT_TRUE(absl::is_trivially_default_constructible<Trivial**>::value);
// types with compiler generated default ctors
EXPECT_TRUE(absl::is_trivially_default_constructible<Trivial>::value);
EXPECT_TRUE(
absl::is_trivially_default_constructible<TrivialDefaultCtor>::value);
// Verify that types without them are not.
EXPECT_FALSE(
absl::is_trivially_default_constructible<NontrivialDefaultCtor>::value);
EXPECT_FALSE(
absl::is_trivially_default_constructible<DeletedDefaultCtor>::value);
#ifdef ABSL_TRIVIALLY_CONSTRUCTIBLE_VERIFY_TRIVIALLY_DESTRUCTIBLE
// types with nontrivial destructor are nontrivial
EXPECT_FALSE(
absl::is_trivially_default_constructible<NontrivialDestructor>::value);
#endif
// types with vtables
EXPECT_FALSE(absl::is_trivially_default_constructible<Base>::value);
// Verify that simple_pair has trivial constructors where applicable.
EXPECT_TRUE((absl::is_trivially_default_constructible<
simple_pair<int, char*>>::value));
EXPECT_TRUE((absl::is_trivially_default_constructible<
simple_pair<int, Trivial>>::value));
EXPECT_TRUE((absl::is_trivially_default_constructible<
simple_pair<int, TrivialDefaultCtor>>::value));
// Verify that types without trivial constructors are
// correctly marked as such.
EXPECT_FALSE(absl::is_trivially_default_constructible<std::string>::value);
EXPECT_FALSE(
absl::is_trivially_default_constructible<std::vector<int>>::value);
// Verify that simple_pairs of types without trivial constructors
// are not marked as trivial.
EXPECT_FALSE((absl::is_trivially_default_constructible<
simple_pair<int, std::string>>::value));
EXPECT_FALSE((absl::is_trivially_default_constructible<
simple_pair<std::string, int>>::value));
// Verify that arrays of such types are trivially default constructible
using int10 = int[10];
EXPECT_TRUE(absl::is_trivially_default_constructible<int10>::value);
using Trivial10 = Trivial[10];
EXPECT_TRUE(absl::is_trivially_default_constructible<Trivial10>::value);
using TrivialDefaultCtor10 = TrivialDefaultCtor[10];
EXPECT_TRUE(
absl::is_trivially_default_constructible<TrivialDefaultCtor10>::value);
// Conversely, the opposite also holds.
#ifdef ABSL_GCC_BUG_TRIVIALLY_CONSTRUCTIBLE_ON_ARRAY_OF_NONTRIVIAL
using NontrivialDefaultCtor10 = NontrivialDefaultCtor[10];
EXPECT_FALSE(
absl::is_trivially_default_constructible<NontrivialDefaultCtor10>::value);
#endif
}
TEST(TypeTraitsTest, TestTrivialCopyCtor) {
// Verify that arithmetic types and pointers have trivial copy
// constructors.
EXPECT_TRUE(absl::is_trivially_copy_constructible<bool>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<char>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<unsigned char>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<signed char>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<wchar_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<int>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<unsigned int>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<int16_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<uint16_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<int64_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<uint64_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<float>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<double>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<long double>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<std::string*>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<Trivial*>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<const std::string*>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<const Trivial*>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<std::string**>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<Trivial**>::value);
// types with compiler generated copy ctors
EXPECT_TRUE(absl::is_trivially_copy_constructible<Trivial>::value);
EXPECT_TRUE(absl::is_trivially_copy_constructible<TrivialCopyCtor>::value);
// Verify that types without them (i.e. nontrivial or deleted) are not.
EXPECT_FALSE(
absl::is_trivially_copy_constructible<NontrivialCopyCtor>::value);
EXPECT_FALSE(absl::is_trivially_copy_constructible<DeletedCopyCtor>::value);
EXPECT_FALSE(
absl::is_trivially_copy_constructible<NonCopyable>::value);
#ifdef ABSL_TRIVIALLY_CONSTRUCTIBLE_VERIFY_TRIVIALLY_DESTRUCTIBLE
// type with nontrivial destructor are nontrivial copy construbtible
EXPECT_FALSE(
absl::is_trivially_copy_constructible<NontrivialDestructor>::value);
#endif
// types with vtables
EXPECT_FALSE(absl::is_trivially_copy_constructible<Base>::value);
// Verify that simple_pair of such types is trivially copy constructible
EXPECT_TRUE(
(absl::is_trivially_copy_constructible<simple_pair<int, char*>>::value));
EXPECT_TRUE((
absl::is_trivially_copy_constructible<simple_pair<int, Trivial>>::value));
EXPECT_TRUE((absl::is_trivially_copy_constructible<
simple_pair<int, TrivialCopyCtor>>::value));
// Verify that types without trivial copy constructors are
// correctly marked as such.
EXPECT_FALSE(absl::is_trivially_copy_constructible<std::string>::value);
EXPECT_FALSE(absl::is_trivially_copy_constructible<std::vector<int>>::value);
// Verify that simple_pairs of types without trivial copy constructors
// are not marked as trivial.
EXPECT_FALSE((absl::is_trivially_copy_constructible<
simple_pair<int, std::string>>::value));
EXPECT_FALSE((absl::is_trivially_copy_constructible<
simple_pair<std::string, int>>::value));
// Verify that arrays are not
using int10 = int[10];
EXPECT_FALSE(absl::is_trivially_copy_constructible<int10>::value);
}
TEST(TypeTraitsTest, TestTrivialCopyAssign) {
// Verify that arithmetic types and pointers have trivial copy
// assignment operators.
EXPECT_TRUE(absl::is_trivially_copy_assignable<bool>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<char>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<unsigned char>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<signed char>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<wchar_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<int>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<unsigned int>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<int16_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<uint16_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<int64_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<uint64_t>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<float>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<double>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<long double>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<std::string*>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<Trivial*>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<const std::string*>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<const Trivial*>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<std::string**>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<Trivial**>::value);
// const qualified types are not assignable
EXPECT_FALSE(absl::is_trivially_copy_assignable<const int>::value);
// types with compiler generated copy assignment
EXPECT_TRUE(absl::is_trivially_copy_assignable<Trivial>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<TrivialCopyAssign>::value);
// Verify that types without them (i.e. nontrivial or deleted) are not.
EXPECT_FALSE(absl::is_trivially_copy_assignable<NontrivialCopyAssign>::value);
EXPECT_FALSE(absl::is_trivially_copy_assignable<DeletedCopyAssign>::value);
EXPECT_FALSE(absl::is_trivially_copy_assignable<NonCopyable>::value);
// types with vtables
EXPECT_FALSE(absl::is_trivially_copy_assignable<Base>::value);
// Verify that simple_pair is trivially assignable
EXPECT_TRUE(
(absl::is_trivially_copy_assignable<simple_pair<int, char*>>::value));
EXPECT_TRUE(
(absl::is_trivially_copy_assignable<simple_pair<int, Trivial>>::value));
EXPECT_TRUE((absl::is_trivially_copy_assignable<
simple_pair<int, TrivialCopyAssign>>::value));
// Verify that types not trivially copy assignable are
// correctly marked as such.
EXPECT_FALSE(absl::is_trivially_copy_assignable<std::string>::value);
EXPECT_FALSE(absl::is_trivially_copy_assignable<std::vector<int>>::value);
// Verify that simple_pairs of types not trivially copy assignable
// are not marked as trivial.
EXPECT_FALSE((absl::is_trivially_copy_assignable<
simple_pair<int, std::string>>::value));
EXPECT_FALSE((absl::is_trivially_copy_assignable<
simple_pair<std::string, int>>::value));
// Verify that arrays are not trivially copy assignable
using int10 = int[10];
EXPECT_FALSE(absl::is_trivially_copy_assignable<int10>::value);
// Verify that references are handled correctly
EXPECT_TRUE(absl::is_trivially_copy_assignable<Trivial&&>::value);
EXPECT_TRUE(absl::is_trivially_copy_assignable<Trivial&>::value);
}
#define ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(trait_name, ...) \
EXPECT_TRUE((std::is_same<typename std::trait_name<__VA_ARGS__>::type, \
absl::trait_name##_t<__VA_ARGS__>>::value))
TEST(TypeTraitsTest, TestRemoveCVAliases) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_cv, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_cv, const int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_cv, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_cv, const volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_const, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_const, const int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_const, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_const, const volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_volatile, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_volatile, const int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_volatile, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_volatile, const volatile int);
}
TEST(TypeTraitsTest, TestAddCVAliases) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_cv, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_cv, const int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_cv, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_cv, const volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_const, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_const, const int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_const, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_const, const volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_volatile, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_volatile, const int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_volatile, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_volatile, const volatile int);
}
TEST(TypeTraitsTest, TestReferenceAliases) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_reference, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_reference, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_reference, int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_reference, volatile int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_reference, int&&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_reference, volatile int&&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_lvalue_reference, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_lvalue_reference, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_lvalue_reference, int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_lvalue_reference, volatile int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_lvalue_reference, int&&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_lvalue_reference, volatile int&&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_rvalue_reference, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_rvalue_reference, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_rvalue_reference, int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_rvalue_reference, volatile int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_rvalue_reference, int&&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_rvalue_reference, volatile int&&);
}
TEST(TypeTraitsTest, TestPointerAliases) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_pointer, int*);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_pointer, volatile int*);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_pointer, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(add_pointer, volatile int);
}
TEST(TypeTraitsTest, TestSignednessAliases) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_signed, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_signed, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_signed, unsigned);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_signed, volatile unsigned);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_unsigned, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_unsigned, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_unsigned, unsigned);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(make_unsigned, volatile unsigned);
}
TEST(TypeTraitsTest, TestExtentAliases) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_extent, int[]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_extent, int[1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_extent, int[1][1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_extent, int[][1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_all_extents, int[]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_all_extents, int[1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_all_extents, int[1][1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(remove_all_extents, int[][1]);
}
TEST(TypeTraitsTest, TestAlignedStorageAlias) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 1);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 2);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 3);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 4);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 5);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 6);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 7);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 8);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 9);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 10);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 11);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 12);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 13);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 14);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 15);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 16);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 17);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 18);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 19);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 20);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 21);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 22);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 23);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 24);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 25);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 26);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 27);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 28);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 29);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 30);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 31);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 32);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 33);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 1, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 2, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 3, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 4, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 5, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 6, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 7, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 8, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 9, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 10, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 11, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 12, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 13, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 14, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 15, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 16, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 17, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 18, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 19, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 20, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 21, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 22, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 23, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 24, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 25, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 26, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 27, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 28, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 29, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 30, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 31, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 32, 128);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(aligned_storage, 33, 128);
}
TEST(TypeTraitsTest, TestDecay) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, const int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, const volatile int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, const int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, volatile int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, const volatile int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, const int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, volatile int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, const volatile int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int[1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int[1][1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int[][1]);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int());
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int(float)); // NOLINT
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(decay, int(char, ...)); // NOLINT
}
struct TypeA {};
struct TypeB {};
struct TypeC {};
struct TypeD {};
template <typename T>
struct Wrap {};
enum class TypeEnum { A, B, C, D };
struct GetTypeT {
template <typename T,
absl::enable_if_t<std::is_same<T, TypeA>::value, int> = 0>
TypeEnum operator()(Wrap<T>) const {
return TypeEnum::A;
}
template <typename T,
absl::enable_if_t<std::is_same<T, TypeB>::value, int> = 0>
TypeEnum operator()(Wrap<T>) const {
return TypeEnum::B;
}
template <typename T,
absl::enable_if_t<std::is_same<T, TypeC>::value, int> = 0>
TypeEnum operator()(Wrap<T>) const {
return TypeEnum::C;
}
// NOTE: TypeD is intentionally not handled
} constexpr GetType = {};
TEST(TypeTraitsTest, TestEnableIf) {
EXPECT_EQ(TypeEnum::A, GetType(Wrap<TypeA>()));
EXPECT_EQ(TypeEnum::B, GetType(Wrap<TypeB>()));
EXPECT_EQ(TypeEnum::C, GetType(Wrap<TypeC>()));
}
TEST(TypeTraitsTest, TestConditional) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(conditional, true, int, char);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(conditional, false, int, char);
}
// TODO(calabrese) Check with specialized std::common_type
TEST(TypeTraitsTest, TestCommonType) {
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(common_type, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(common_type, int, char);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(common_type, int, char, int);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(common_type, int&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(common_type, int, char&);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(common_type, int, char, int&);
}
TEST(TypeTraitsTest, TestUnderlyingType) {
enum class enum_char : char {};
enum class enum_long_long : long long {}; // NOLINT(runtime/int)
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(underlying_type, enum_char);
ABSL_INTERNAL_EXPECT_ALIAS_EQUIVALENCE(underlying_type, enum_long_long);
}
struct GetTypeExtT {
template <typename T>
absl::result_of_t<const GetTypeT&(T)> operator()(T&& arg) const {
return GetType(std::forward<T>(arg));
}
TypeEnum operator()(Wrap<TypeD>) const { return TypeEnum::D; }
} constexpr GetTypeExt = {};
TEST(TypeTraitsTest, TestResultOf) {
EXPECT_EQ(TypeEnum::A, GetTypeExt(Wrap<TypeA>()));
EXPECT_EQ(TypeEnum::B, GetTypeExt(Wrap<TypeB>()));
EXPECT_EQ(TypeEnum::C, GetTypeExt(Wrap<TypeC>()));
EXPECT_EQ(TypeEnum::D, GetTypeExt(Wrap<TypeD>()));
}
template <typename T>
bool TestCopyAssign() {
return absl::is_copy_assignable<T>::value ==
std::is_copy_assignable<T>::value;
}
TEST(TypeTraitsTest, IsCopyAssignable) {
EXPECT_TRUE(TestCopyAssign<int>());
EXPECT_TRUE(TestCopyAssign<int&>());
EXPECT_TRUE(TestCopyAssign<int&&>());
struct S {};
EXPECT_TRUE(TestCopyAssign<S>());
EXPECT_TRUE(TestCopyAssign<S&>());
EXPECT_TRUE(TestCopyAssign<S&&>());
class C {
public:
explicit C(C* c) : c_(c) {}
~C() { delete c_; }
private:
C* c_;
};
EXPECT_TRUE(TestCopyAssign<C>());
EXPECT_TRUE(TestCopyAssign<C&>());
EXPECT_TRUE(TestCopyAssign<C&&>());
// Reason for ifndef: add_lvalue_reference<T> in libc++ breaks for these cases
#ifndef _LIBCPP_VERSION
EXPECT_TRUE(TestCopyAssign<int()>());
EXPECT_TRUE(TestCopyAssign<int(int) const>());
EXPECT_TRUE(TestCopyAssign<int(...) volatile&>());
EXPECT_TRUE(TestCopyAssign<int(int, ...) const volatile&&>());
#endif // _LIBCPP_VERSION
}
template <typename T>
bool TestMoveAssign() {
return absl::is_move_assignable<T>::value ==
std::is_move_assignable<T>::value;
}
TEST(TypeTraitsTest, IsMoveAssignable) {
EXPECT_TRUE(TestMoveAssign<int>());
EXPECT_TRUE(TestMoveAssign<int&>());
EXPECT_TRUE(TestMoveAssign<int&&>());
struct S {};
EXPECT_TRUE(TestMoveAssign<S>());
EXPECT_TRUE(TestMoveAssign<S&>());
EXPECT_TRUE(TestMoveAssign<S&&>());
class C {
public:
explicit C(C* c) : c_(c) {}
~C() { delete c_; }
void operator=(const C&) = delete;
void operator=(C&&) = delete;
private:
C* c_;
};
EXPECT_TRUE(TestMoveAssign<C>());
EXPECT_TRUE(TestMoveAssign<C&>());
EXPECT_TRUE(TestMoveAssign<C&&>());
// Reason for ifndef: add_lvalue_reference<T> in libc++ breaks for these cases
#ifndef _LIBCPP_VERSION
EXPECT_TRUE(TestMoveAssign<int()>());
EXPECT_TRUE(TestMoveAssign<int(int) const>());
EXPECT_TRUE(TestMoveAssign<int(...) volatile&>());
EXPECT_TRUE(TestMoveAssign<int(int, ...) const volatile&&>());
#endif // _LIBCPP_VERSION
}
namespace adl_namespace {
struct DeletedSwap {
};
void swap(DeletedSwap&, DeletedSwap&) = delete;
struct SpecialNoexceptSwap {
SpecialNoexceptSwap(SpecialNoexceptSwap&&) {}
SpecialNoexceptSwap& operator=(SpecialNoexceptSwap&&) { return *this; }
~SpecialNoexceptSwap() = default;
};
void swap(SpecialNoexceptSwap&, SpecialNoexceptSwap&) noexcept {}
} // namespace adl_namespace
TEST(TypeTraitsTest, IsSwappable) {
using absl::type_traits_internal::IsSwappable;
using absl::type_traits_internal::StdSwapIsUnconstrained;
EXPECT_TRUE(IsSwappable<int>::value);
struct S {};
EXPECT_TRUE(IsSwappable<S>::value);
struct NoConstruct {
NoConstruct(NoConstruct&&) = delete;
NoConstruct& operator=(NoConstruct&&) { return *this; }
~NoConstruct() = default;
};
EXPECT_EQ(IsSwappable<NoConstruct>::value, StdSwapIsUnconstrained::value);
struct NoAssign {
NoAssign(NoAssign&&) {}
NoAssign& operator=(NoAssign&&) = delete;
~NoAssign() = default;
};
EXPECT_EQ(IsSwappable<NoAssign>::value, StdSwapIsUnconstrained::value);
EXPECT_FALSE(IsSwappable<adl_namespace::DeletedSwap>::value);
EXPECT_TRUE(IsSwappable<adl_namespace::SpecialNoexceptSwap>::value);
}
TEST(TypeTraitsTest, IsNothrowSwappable) {
using absl::type_traits_internal::IsNothrowSwappable;
using absl::type_traits_internal::StdSwapIsUnconstrained;
EXPECT_TRUE(IsNothrowSwappable<int>::value);
struct NonNoexceptMoves {
NonNoexceptMoves(NonNoexceptMoves&&) {}
NonNoexceptMoves& operator=(NonNoexceptMoves&&) { return *this; }
~NonNoexceptMoves() = default;
};
EXPECT_FALSE(IsNothrowSwappable<NonNoexceptMoves>::value);
struct NoConstruct {
NoConstruct(NoConstruct&&) = delete;
NoConstruct& operator=(NoConstruct&&) { return *this; }
~NoConstruct() = default;
};
EXPECT_FALSE(IsNothrowSwappable<NoConstruct>::value);
struct NoAssign {
NoAssign(NoAssign&&) {}
NoAssign& operator=(NoAssign&&) = delete;
~NoAssign() = default;
};
EXPECT_FALSE(IsNothrowSwappable<NoAssign>::value);
EXPECT_FALSE(IsNothrowSwappable<adl_namespace::DeletedSwap>::value);
EXPECT_TRUE(IsNothrowSwappable<adl_namespace::SpecialNoexceptSwap>::value);
}
} // namespace