diff options
Diffstat (limited to 'absl/meta/type_traits.h')
| -rw-r--r-- | absl/meta/type_traits.h | 45 |
1 files changed, 37 insertions, 8 deletions
diff --git a/absl/meta/type_traits.h b/absl/meta/type_traits.h index d57a879..8cd5f04 100644 --- a/absl/meta/type_traits.h +++ b/absl/meta/type_traits.h @@ -41,10 +41,20 @@ #include "absl/base/config.h" +// MSVC constructibility traits do not detect destructor properties and so our +// implementations should not use them as a source-of-truth. +#if defined(_MSC_VER) && !defined(__clang__) && !defined(__GNUC__) +#define ABSL_META_INTERNAL_STD_CONSTRUCTION_TRAITS_DONT_CHECK_DESTRUCTION 1 +#endif + namespace absl { // Defined and documented later on in this file. template <typename T> +struct is_trivially_destructible; + +// Defined and documented later on in this file. +template <typename T> struct is_trivially_move_assignable; namespace type_traits_internal { @@ -66,6 +76,20 @@ union SingleMemberUnion { #endif // defined(_MSC_VER) && !defined(__GNUC__) template <class T> +struct IsTriviallyMoveConstructibleObject + : std::integral_constant< + bool, std::is_move_constructible< + type_traits_internal::SingleMemberUnion<T>>::value && + absl::is_trivially_destructible<T>::value> {}; + +template <class T> +struct IsTriviallyCopyConstructibleObject + : std::integral_constant< + bool, std::is_copy_constructible< + type_traits_internal::SingleMemberUnion<T>>::value && + absl::is_trivially_destructible<T>::value> {}; + +template <class T> struct IsTriviallyMoveAssignableReference : std::false_type {}; template <class T> @@ -323,7 +347,9 @@ struct is_trivially_default_constructible : std::integral_constant<bool, __has_trivial_constructor(T) && std::is_default_constructible<T>::value && is_trivially_destructible<T>::value> { -#ifdef ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE +#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE) && \ + !defined( \ + ABSL_META_INTERNAL_STD_CONSTRUCTION_TRAITS_DONT_CHECK_DESTRUCTION) private: static constexpr bool compliant = std::is_trivially_default_constructible<T>::value == @@ -354,10 +380,11 @@ template <typename T> struct is_trivially_move_constructible : std::conditional< std::is_object<T>::value && !std::is_array<T>::value, - std::is_move_constructible< - type_traits_internal::SingleMemberUnion<T>>, + type_traits_internal::IsTriviallyMoveConstructibleObject<T>, std::is_reference<T>>::type::type { -#ifdef ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE +#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE) && \ + !defined( \ + ABSL_META_INTERNAL_STD_CONSTRUCTION_TRAITS_DONT_CHECK_DESTRUCTION) private: static constexpr bool compliant = std::is_trivially_move_constructible<T>::value == @@ -388,10 +415,11 @@ template <typename T> struct is_trivially_copy_constructible : std::conditional< std::is_object<T>::value && !std::is_array<T>::value, - std::is_copy_constructible< - type_traits_internal::SingleMemberUnion<T>>, + type_traits_internal::IsTriviallyCopyConstructibleObject<T>, std::is_lvalue_reference<T>>::type::type { -#ifdef ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE +#if defined(ABSL_HAVE_STD_IS_TRIVIALLY_CONSTRUCTIBLE) && \ + !defined( \ + ABSL_META_INTERNAL_STD_CONSTRUCTION_TRAITS_DONT_CHECK_DESTRUCTION) private: static constexpr bool compliant = std::is_trivially_copy_constructible<T>::value == @@ -423,7 +451,8 @@ struct is_trivially_copy_constructible template <typename T> struct is_trivially_move_assignable : std::conditional< - std::is_object<T>::value && !std::is_array<T>::value, + std::is_object<T>::value && !std::is_array<T>::value && + std::is_move_assignable<T>::value, std::is_move_assignable<type_traits_internal::SingleMemberUnion<T>>, type_traits_internal::IsTriviallyMoveAssignableReference<T>>::type:: type { |