diff options
author | Abseil Team <absl-team@google.com> | 2019-04-09T15·22-0700 |
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committer | Shaindel Schwartz <shaindel@google.com> | 2019-04-09T17·34-0400 |
commit | dbae8764fbd429bf7d7745e24bcf73962177a7c0 (patch) | |
tree | 9e0b90d17192c02952632d619616f00ec4f68580 /absl/types/internal | |
parent | 044da8a29c923506af0f0b46bc46f43c1e1300b5 (diff) |
Export of internal Abseil changes.
-- 3f04cd3c25a99df91ff913977b8c5b343532db5d by Abseil Team <absl-team@google.com>: Stricter memory order constraints for CycleClock callback. PiperOrigin-RevId: 242670115 -- 216db48375306490f1722a11aaf33080939d9f2f by Abseil Team <absl-team@google.com>: internal/optional.h: move macro from types/optional.h ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS is only used within this file. additionally check the macro with #ifdef rather than #if, fixes -Wundef warning: 'ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS' is not defined, evaluates to 0 PiperOrigin-RevId: 242548205 -- fbe22e7d8dc5c0b3d43ac26297e97ddbaeab3d39 by Samuel Benzaquen <sbenza@google.com>: Implement %f natively for any input. It evaluates the input at runtime and allocates stack space accordingly. This removes a potential fallback into snprintf, improves performance, and removes all memory allocations in this formatting path. PiperOrigin-RevId: 242531736 -- 1458f9ba2a79ef0534e46527cd34770dee54164d by Greg Falcon <gfalcon@google.com>: Add explicit check for NVCC in compressed_tuple.h. NVCC claims to be MSVC, but does not implement this MSVC attribute. PiperOrigin-RevId: 242513453 GitOrigin-RevId: 3f04cd3c25a99df91ff913977b8c5b343532db5d Change-Id: I0742e8619c5248c7607961113e406486bc0e279b
Diffstat (limited to 'absl/types/internal')
-rw-r--r-- | absl/types/internal/optional.h | 36 |
1 files changed, 33 insertions, 3 deletions
diff --git a/absl/types/internal/optional.h b/absl/types/internal/optional.h index 562c84ef5af7..8acbda20d559 100644 --- a/absl/types/internal/optional.h +++ b/absl/types/internal/optional.h @@ -25,6 +25,34 @@ #include "absl/meta/type_traits.h" #include "absl/utility/utility.h" +// ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +// +// Inheriting constructors is supported in GCC 4.8+, Clang 3.3+ and MSVC 2015. +// __cpp_inheriting_constructors is a predefined macro and a recommended way to +// check for this language feature, but GCC doesn't support it until 5.0 and +// Clang doesn't support it until 3.6. +// Also, MSVC 2015 has a bug: it doesn't inherit the constexpr template +// constructor. For example, the following code won't work on MSVC 2015 Update3: +// struct Base { +// int t; +// template <typename T> +// constexpr Base(T t_) : t(t_) {} +// }; +// struct Foo : Base { +// using Base::Base; +// } +// constexpr Foo foo(0); // doesn't work on MSVC 2015 +#if defined(__clang__) +#if __has_feature(cxx_inheriting_constructors) +#define ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS 1 +#endif +#elif (defined(__GNUC__) && \ + (__GNUC__ > 4 || __GNUC__ == 4 && __GNUC_MINOR__ >= 8)) || \ + (__cpp_inheriting_constructors >= 200802) || \ + (defined(_MSC_VER) && _MSC_VER >= 1910) +#define ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS 1 +#endif + namespace absl { // Forward declaration @@ -108,7 +136,7 @@ template <typename T> class optional_data_base : public optional_data_dtor_base<T> { protected: using base = optional_data_dtor_base<T>; -#if ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +#ifdef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS using base::base; #else optional_data_base() = default; @@ -151,7 +179,7 @@ class optional_data; template <typename T> class optional_data<T, true> : public optional_data_base<T> { protected: -#if ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +#ifdef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS using optional_data_base<T>::optional_data_base; #else optional_data() = default; @@ -165,7 +193,7 @@ class optional_data<T, true> : public optional_data_base<T> { template <typename T> class optional_data<T, false> : public optional_data_base<T> { protected: -#if ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS +#ifdef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS using optional_data_base<T>::optional_data_base; #else template <typename... Args> @@ -361,4 +389,6 @@ struct optional_hash_base<T, decltype(std::hash<absl::remove_const_t<T> >()( } // namespace optional_internal } // namespace absl +#undef ABSL_OPTIONAL_USE_INHERITING_CONSTRUCTORS + #endif // ABSL_TYPES_INTERNAL_OPTIONAL_H_ |