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authorGravatar Abseil Team <absl-team@google.com>2022-08-05 06:56:05 -0700
committerGravatar Copybara-Service <copybara-worker@google.com>2022-08-05 06:56:59 -0700
commitcfe27e79cfcbefb2b4479e04f80cbb299bc46965 (patch)
tree7294acf94b9892a35927c5967c950192ed2acc2c /absl
parentc9736080610480eac20c946f0369ff0d05679842 (diff)
Map the absl::is_trivially_* functions to their std impl
There's no point redefining these functions if they are supported by the compiler and the version of libstdc++. Also, some of the builtins used by the absl implementation of these functions (e.g. __has_trivial_destructor) have been deprecated in Clang 15. PiperOrigin-RevId: 465554125 Change-Id: I8674c3a5270ce3c654cdf58ae7dbd9d2bda8faa5
Diffstat (limited to 'absl')
-rw-r--r--absl/base/config.h11
-rw-r--r--absl/meta/type_traits.h22
-rw-r--r--absl/meta/type_traits_test.cc1
3 files changed, 34 insertions, 0 deletions
diff --git a/absl/base/config.h b/absl/base/config.h
index 94f7fcb5..2faed85a 100644
--- a/absl/base/config.h
+++ b/absl/base/config.h
@@ -273,6 +273,17 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' ||
#define ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE 1
#endif
+// ABSL_HAVE_STD_IS_TRIVIALLY_COPYABLE
+//
+// Checks whether `std::is_trivially_copyable<T>` is supported.
+//
+// Notes: Clang 15+ with libc++ supports these features, GCC hasn't been tested.
+#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_COPYABLE)
+#error ABSL_HAVE_STD_IS_TRIVIALLY_COPYABLE cannot be directly set
+#elif defined(__clang__) && (__clang_major__ >= 15)
+#define ABSL_HAVE_STD_IS_TRIVIALLY_COPYABLE 1
+#endif
+
// ABSL_HAVE_THREAD_LOCAL
//
// Checks whether C++11's `thread_local` storage duration specifier is
diff --git a/absl/meta/type_traits.h b/absl/meta/type_traits.h
index d886cb30..46b76906 100644
--- a/absl/meta/type_traits.h
+++ b/absl/meta/type_traits.h
@@ -298,8 +298,12 @@ struct is_function
// https://gcc.gnu.org/onlinedocs/gcc/Type-Traits.html#Type-Traits.
template <typename T>
struct is_trivially_destructible
+#ifdef ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE
+ : std::is_trivially_destructible<T> {
+#else
: std::integral_constant<bool, __has_trivial_destructor(T) &&
std::is_destructible<T>::value> {
+#endif
#ifdef ABSL_HAVE_STD_IS_TRIVIALLY_DESTRUCTIBLE
private:
static constexpr bool compliant = std::is_trivially_destructible<T>::value ==
@@ -347,9 +351,13 @@ struct is_trivially_destructible
// Nontrivially destructible types will cause the expression to be nontrivial.
template <typename T>
struct is_trivially_default_constructible
+#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE)
+ : std::is_trivially_default_constructible<T> {
+#else
: std::integral_constant<bool, __has_trivial_constructor(T) &&
std::is_default_constructible<T>::value &&
is_trivially_destructible<T>::value> {
+#endif
#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE) && \
!defined( \
ABSL_META_INTERNAL_STD_CONSTRUCTION_TRAITS_DONT_CHECK_DESTRUCTION)
@@ -381,10 +389,14 @@ struct is_trivially_default_constructible
// expression to be nontrivial.
template <typename T>
struct is_trivially_move_constructible
+#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE)
+ : std::is_trivially_move_constructible<T> {
+#else
: std::conditional<
std::is_object<T>::value && !std::is_array<T>::value,
type_traits_internal::IsTriviallyMoveConstructibleObject<T>,
std::is_reference<T>>::type::type {
+#endif
#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE) && \
!defined( \
ABSL_META_INTERNAL_STD_CONSTRUCTION_TRAITS_DONT_CHECK_DESTRUCTION)
@@ -490,9 +502,13 @@ struct is_trivially_move_assignable
// `is_trivially_assignable<T&, const T&>`.
template <typename T>
struct is_trivially_copy_assignable
+#ifdef ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE
+ : std::is_trivially_copy_assignable<T> {
+#else
: std::integral_constant<
bool, __has_trivial_assign(typename std::remove_reference<T>::type) &&
absl::is_copy_assignable<T>::value> {
+#endif
#ifdef ABSL_HAVE_STD_IS_TRIVIALLY_ASSIGNABLE
private:
static constexpr bool compliant =
@@ -544,6 +560,11 @@ namespace type_traits_internal {
// destructible. Arrays of trivially copyable types are trivially copyable.
//
// We expose this metafunction only for internal use within absl.
+
+#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_COPYABLE)
+template <typename T>
+struct is_trivially_copyable : std::is_trivially_copyable<T> {};
+#else
template <typename T>
class is_trivially_copyable_impl {
using ExtentsRemoved = typename std::remove_all_extents<T>::type;
@@ -569,6 +590,7 @@ template <typename T>
struct is_trivially_copyable
: std::integral_constant<
bool, type_traits_internal::is_trivially_copyable_impl<T>::kValue> {};
+#endif
} // namespace type_traits_internal
// -----------------------------------------------------------------------------
diff --git a/absl/meta/type_traits_test.cc b/absl/meta/type_traits_test.cc
index 0ef5b665..fe96554d 100644
--- a/absl/meta/type_traits_test.cc
+++ b/absl/meta/type_traits_test.cc
@@ -336,6 +336,7 @@ struct MovableNonCopyable {
struct NonCopyableOrMovable {
NonCopyableOrMovable() = default;
+ virtual ~NonCopyableOrMovable() = default;
NonCopyableOrMovable(const NonCopyableOrMovable&) = delete;
NonCopyableOrMovable(NonCopyableOrMovable&&) = delete;
NonCopyableOrMovable& operator=(const NonCopyableOrMovable&) = delete;