diff options
Diffstat (limited to 'absl/base')
| -rw-r--r-- | absl/base/config.h | 32 | ||||
| -rw-r--r-- | absl/base/options.h | 26 |
2 files changed, 58 insertions, 0 deletions
diff --git a/absl/base/config.h b/absl/base/config.h index b0e7fe8b..0fb66927 100644 --- a/absl/base/config.h +++ b/absl/base/config.h @@ -609,6 +609,22 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' || #define ABSL_HAVE_STD_STRING_VIEW 1 #endif +// ABSL_HAVE_STD_ORDERING +// +// Checks whether C++20 std::{partial,weak,strong}_ordering are available. +// +// __cpp_lib_three_way_comparison is missing on libc++ +// (https://github.com/llvm/llvm-project/issues/73953) so treat it as defined +// when building in C++20 mode. +#ifdef ABSL_HAVE_STD_ORDERING +#error "ABSL_HAVE_STD_ORDERING cannot be directly set." +#elif (defined(__cpp_lib_three_way_comparison) && \ + __cpp_lib_three_way_comparison >= 201907L) || \ + (defined(ABSL_INTERNAL_CPLUSPLUS_LANG) && \ + ABSL_INTERNAL_CPLUSPLUS_LANG >= 202002L) +#define ABSL_HAVE_STD_ORDERING 1 +#endif + // ABSL_USES_STD_ANY // // Indicates whether absl::any is an alias for std::any. @@ -671,6 +687,22 @@ static_assert(ABSL_INTERNAL_INLINE_NAMESPACE_STR[0] != 'h' || #error options.h is misconfigured. #endif +// ABSL_USES_STD_ORDERING +// +// Indicates whether absl::{partial,weak,strong}_ordering are aliases for the +// std:: ordering types. +#if !defined(ABSL_OPTION_USE_STD_ORDERING) +#error options.h is misconfigured. +#elif ABSL_OPTION_USE_STD_ORDERING == 0 || \ + (ABSL_OPTION_USE_STD_ORDERING == 2 && !defined(ABSL_HAVE_STD_ORDERING)) +#undef ABSL_USES_STD_ORDERING +#elif ABSL_OPTION_USE_STD_ORDERING == 1 || \ + (ABSL_OPTION_USE_STD_ORDERING == 2 && defined(ABSL_HAVE_STD_ORDERING)) +#define ABSL_USES_STD_ORDERING 1 +#else +#error options.h is misconfigured. +#endif + // In debug mode, MSVC 2017's std::variant throws a EXCEPTION_ACCESS_VIOLATION // SEH exception from emplace for variant<SomeStruct> when constructing the // struct can throw. This defeats some of variant_test and diff --git a/absl/base/options.h b/absl/base/options.h index 5c162a38..a169658f 100644 --- a/absl/base/options.h +++ b/absl/base/options.h @@ -176,6 +176,32 @@ #define ABSL_OPTION_USE_STD_VARIANT 2 +// ABSL_OPTION_USE_STD_ORDERING +// +// This option controls whether absl::{partial,weak,strong}_ordering are +// implemented as aliases to the std:: ordering types, or as an independent +// implementation. +// +// A value of 0 means to use Abseil's implementation. This requires only C++11 +// support, and is expected to work on every toolchain we support. +// +// A value of 1 means to use aliases. This requires that all code using Abseil +// is built in C++20 mode or later. +// +// A value of 2 means to detect the C++ version being used to compile Abseil, +// and use an alias only if working std:: ordering types are available. This +// option is useful when you are building your program from source. It should +// not be used otherwise -- for example, if you are distributing Abseil in a +// binary package manager -- since in mode 2, they will name different types, +// with different mangled names and binary layout, depending on the compiler +// flags passed by the end user. For more info, see +// https://abseil.io/about/design/dropin-types. +// +// User code should not inspect this macro. To check in the preprocessor if +// the ordering types are aliases of std:: ordering types, use the feature macro +// ABSL_USES_STD_ORDERING. + +#define ABSL_OPTION_USE_STD_ORDERING 2 // ABSL_OPTION_USE_INLINE_NAMESPACE // ABSL_OPTION_INLINE_NAMESPACE_NAME |