diff options
Diffstat (limited to 'absl/meta/type_traits_test.cc')
| -rw-r--r-- | absl/meta/type_traits_test.cc | 43 |
1 files changed, 22 insertions, 21 deletions
diff --git a/absl/meta/type_traits_test.cc b/absl/meta/type_traits_test.cc index a7a9c5c9..1aafd0d4 100644 --- a/absl/meta/type_traits_test.cc +++ b/absl/meta/type_traits_test.cc @@ -347,21 +347,6 @@ class Base { 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. @@ -499,11 +484,9 @@ TEST(TypeTraitsTest, TestTrivialDefaultCtor) { 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); @@ -546,6 +529,28 @@ TEST(TypeTraitsTest, TestTrivialDefaultCtor) { #endif } +// GCC prior to 7.4 had a bug in its trivially-constructible traits +// (https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80654). +// This test makes sure that we do not depend on the trait in these cases when +// implementing absl triviality traits. + +template <class T> +struct BadConstructors { + BadConstructors() { static_assert(T::value, ""); } + + BadConstructors(BadConstructors&&) { static_assert(T::value, ""); } + + BadConstructors(const BadConstructors&) { static_assert(T::value, ""); } +}; + +TEST(TypeTraitsTest, TestTrivialityBadConstructors) { + using BadType = BadConstructors<int>; + + EXPECT_FALSE(absl::is_trivially_default_constructible<BadType>::value); + EXPECT_FALSE(absl::is_trivially_move_constructible<BadType>::value); + EXPECT_FALSE(absl::is_trivially_copy_constructible<BadType>::value); +} + TEST(TypeTraitsTest, TestTrivialMoveCtor) { // Verify that arithmetic types and pointers have trivial move // constructors. @@ -585,11 +590,9 @@ TEST(TypeTraitsTest, TestTrivialMoveCtor) { EXPECT_FALSE( absl::is_trivially_move_constructible<NonCopyableOrMovable>::value); -#ifdef ABSL_TRIVIALLY_CONSTRUCTIBLE_VERIFY_TRIVIALLY_DESTRUCTIBLE // type with nontrivial destructor are nontrivial move construbtible EXPECT_FALSE( absl::is_trivially_move_constructible<NontrivialDestructor>::value); -#endif // types with vtables EXPECT_FALSE(absl::is_trivially_move_constructible<Base>::value); @@ -660,11 +663,9 @@ TEST(TypeTraitsTest, TestTrivialCopyCtor) { EXPECT_FALSE( absl::is_trivially_copy_constructible<NonCopyableOrMovable>::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); |