diff options
| -rw-r--r-- | absl/base/attributes.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/absl/base/attributes.h b/absl/base/attributes.h index 91bf954b..a6572d08 100644 --- a/absl/base/attributes.h +++ b/absl/base/attributes.h @@ -787,7 +787,15 @@ // For code that is assured to only build with C++20 or later, prefer using // the standard attribute `[[no_unique_address]]` directly instead of this // macro. -#if ABSL_HAVE_CPP_ATTRIBUTE(no_unique_address) +// +// https://devblogs.microsoft.com/cppblog/msvc-cpp20-and-the-std-cpp20-switch/#c20-no_unique_address +// Current versions of MSVC have disabled `[[no_unique_address]]` since it +// breaks ABI compatibility, but offers `[[msvc::no_unique_address]]` for +// situations when it can be assured that it is desired. Since Abseil does not +// claim ABI compatibility in mixed builds, we can offer it unconditionally. +#if defined(_MSC_VER) && _MSC_VER >= 1929 +#define ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS [[msvc::no_unique_address]] +#elif ABSL_HAVE_CPP_ATTRIBUTE(no_unique_address) #define ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS [[no_unique_address]] #else #define ABSL_ATTRIBUTE_NO_UNIQUE_ADDRESS |