FOLLY_HAS_TRUE_XXX(IsTriviallyCopyable)
#undef FOLLY_HAS_TRUE_XXX
+
+// Older versions of libstdc++ do not provide std::is_trivially_copyable
+#if defined(__clang__) && !defined(_LIBCPP_VERSION)
+template <class T>
+struct is_trivially_copyable
+ : std::integral_constant<bool, __is_trivially_copyable(T)> {};
+#elif defined(__GNUC__) && !defined(__clang__) && __GNUC__ < 5
+template <class T>
+struct is_trivially_copyable : std::is_trivial<T> {};
+#else
+template <class T>
+using is_trivially_copyable = std::is_trivially_copyable<T>;
+#endif
+}
+
+struct Ignore {
+ template <class T>
+ /* implicit */ Ignore(const T&) {}
+ template <class T>
+ const Ignore& operator=(T const&) const { return *this; }
+};
+
+template <class...>
+using Ignored = Ignore;
+
+namespace traits_detail_IsEqualityComparable {
+Ignore operator==(Ignore, Ignore);
+
+template <class T, class U = T>
+struct IsEqualityComparable
+ : std::is_convertible<
+ decltype(std::declval<T>() == std::declval<U>()),
+ bool
+ > {};
+}
+
+/* using override */ using traits_detail_IsEqualityComparable::
+ IsEqualityComparable;
+
+namespace traits_detail_IsLessThanComparable {
+Ignore operator<(Ignore, Ignore);
+
+template <class T, class U = T>
+struct IsLessThanComparable
+ : std::is_convertible<
+ decltype(std::declval<T>() < std::declval<U>()),
+ bool
+ > {};
+}
+
+/* using override */ using traits_detail_IsLessThanComparable::
+ IsLessThanComparable;
+
+namespace traits_detail_IsNothrowSwappable {
+#if defined(_MSC_VER) || defined(__cpp_lib_is_swappable)
+// MSVC already implements the C++17 P0185R1 proposal which
+// adds std::is_nothrow_swappable, so use it instead.
+template <typename T>
+using IsNothrowSwappable = std::is_nothrow_swappable<T>;
+#else
+/* using override */ using std::swap;
+
+template <class T>
+struct IsNothrowSwappable
+ : std::integral_constant<bool,
+ std::is_nothrow_move_constructible<T>::value &&
+ noexcept(swap(std::declval<T&>(), std::declval<T&>()))
+ > {};
+#endif
}
+/* using override */ using traits_detail_IsNothrowSwappable::IsNothrowSwappable;
+
template <class T> struct IsTriviallyCopyable
- : std::integral_constant<bool,
- !std::is_class<T>::value ||
- // TODO: add alternate clause is_trivially_copyable, when available
- traits_detail::has_true_IsTriviallyCopyable<T>::value
- > {};
+ : std::conditional<
+ traits_detail::has_IsTriviallyCopyable<T>::value,
+ traits_detail::has_true_IsTriviallyCopyable<T>,
+ traits_detail::is_trivially_copyable<T>
+ >::type {};
template <class T> struct IsRelocatable
- : std::integral_constant<bool,
- !std::is_class<T>::value ||
+ : std::conditional<
+ traits_detail::has_IsRelocatable<T>::value,
+ traits_detail::has_true_IsRelocatable<T>,
// TODO add this line (and some tests for it) when we upgrade to gcc 4.7
//std::is_trivially_move_constructible<T>::value ||
- IsTriviallyCopyable<T>::value ||
- traits_detail::has_true_IsRelocatable<T>::value
- > {};
+ IsTriviallyCopyable<T>
+ >::type {};
template <class T> struct IsZeroInitializable
- : std::integral_constant<bool,
- !std::is_class<T>::value ||
- traits_detail::has_true_IsZeroInitializable<T>::value
- > {};
+ : std::conditional<
+ traits_detail::has_IsZeroInitializable<T>::value,
+ traits_detail::has_true_IsZeroInitializable<T>,
+ std::integral_constant<bool, !std::is_class<T>::value>
+ >::type {};
template <typename...>
struct Conjunction : std::true_type {};
template <typename T>
struct Negation : std::integral_constant<bool, !T::value> {};
+template <bool... Bs>
+struct Bools {
+ using valid_type = bool;
+ static constexpr std::size_t size() {
+ return sizeof...(Bs);
+ }
+};
+
+// Lighter-weight than Conjunction, but evaluates all sub-conditions eagerly.
+template <class... Ts>
+using StrictConjunction =
+ std::is_same<Bools<Ts::value..., true>, Bools<true, Ts::value...>>;
+
} // namespace folly
/**
>(lhs);
}
+namespace traits_detail {
+struct InPlaceTag {};
+template <class>
+struct InPlaceTypeTag {};
+template <std::size_t>
+struct InPlaceIndexTag {};
+}
+
/**
* Like std::piecewise_construct, a tag type & instance used for in-place
* construction of non-movable contained types, e.g. by Synchronized.
+ * Follows the naming and design of std::in_place suggested in
+ * http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2016/p0032r2.pdf
*/
-struct construct_in_place_t {};
-constexpr construct_in_place_t construct_in_place{};
+using in_place_t = traits_detail::InPlaceTag (&)(traits_detail::InPlaceTag);
+
+template <class T>
+using in_place_type_t =
+ traits_detail::InPlaceTypeTag<T> (&)(traits_detail::InPlaceTypeTag<T>);
+
+template <std::size_t I>
+using in_place_index_t =
+ traits_detail::InPlaceIndexTag<I> (&)(traits_detail::InPlaceIndexTag<I>);
+
+inline traits_detail::InPlaceTag in_place(traits_detail::InPlaceTag = {}) {
+ return {};
+}
+
+template <class T>
+inline traits_detail::InPlaceTypeTag<T> in_place(
+ traits_detail::InPlaceTypeTag<T> = {}) {
+ return {};
+}
+
+template <std::size_t I>
+inline traits_detail::InPlaceIndexTag<I> in_place(
+ traits_detail::InPlaceIndexTag<I> = {}) {
+ return {};
+}
+
+// For backwards compatibility:
+using construct_in_place_t = in_place_t;
+
+inline traits_detail::InPlaceTag construct_in_place(
+ traits_detail::InPlaceTag = {}) {
+ return {};
+}
/**
* Initializer lists are a powerful compile time syntax introduced in C++11
classname, func_name, /* nolint */ volatile); \
FOLLY_CREATE_HAS_MEMBER_FN_TRAITS_IMPL( \
classname, func_name, /* nolint */ volatile const)
+
+/* Some combinations of compilers and C++ libraries make __int128 and
+ * unsigned __int128 available but do not correctly define their standard type
+ * traits.
+ *
+ * If FOLLY_SUPPLY_MISSING_INT128_TRAITS is defined, we define these traits
+ * here.
+ *
+ * @author: Phil Willoughby <philwill@fb.com>
+ */
+#if FOLLY_SUPPLY_MISSING_INT128_TRAITS
+FOLLY_NAMESPACE_STD_BEGIN
+template <>
+struct is_arithmetic<__int128> : ::std::true_type {};
+template <>
+struct is_arithmetic<unsigned __int128> : ::std::true_type {};
+template <>
+struct is_integral<__int128> : ::std::true_type {};
+template <>
+struct is_integral<unsigned __int128> : ::std::true_type {};
+template <>
+struct make_unsigned<__int128> {
+ typedef unsigned __int128 type;
+};
+template <>
+struct make_signed<__int128> {
+ typedef __int128 type;
+};
+template <>
+struct make_unsigned<unsigned __int128> {
+ typedef unsigned __int128 type;
+};
+template <>
+struct make_signed<unsigned __int128> {
+ typedef __int128 type;
+};
+template <>
+struct is_signed<__int128> : ::std::true_type {};
+template <>
+struct is_unsigned<unsigned __int128> : ::std::true_type {};
+FOLLY_NAMESPACE_STD_END
+#endif // FOLLY_SUPPLY_MISSING_INT128_TRAITS
projects / folly.git / blobdiff