diff options
Diffstat (limited to 'absl/base/nullability.h')
| -rw-r--r-- | absl/base/nullability.h | 40 |
1 files changed, 33 insertions, 7 deletions
diff --git a/absl/base/nullability.h b/absl/base/nullability.h index 6f49b6f5..34dc083a 100644 --- a/absl/base/nullability.h +++ b/absl/base/nullability.h @@ -128,9 +128,17 @@ // // By default, nullability annotations are applicable to raw and smart // pointers. User-defined types can indicate compatibility with nullability -// annotations by providing an `absl_nullability_compatible` nested type. The -// actual definition of this inner type is not relevant as it is used merely as -// a marker. It is common to use a using declaration of +// annotations by adding the ABSL_NULLABILITY_COMPATIBLE attribute. +// +// // Example: +// struct ABSL_NULLABILITY_COMPATIBLE MyPtr { +// ... +// }; +// +// Note: For the time being, nullability-compatible classes should additionally +// be marked with an `absl_nullability_compatible` nested type (this will soon +// be deprecated). The actual definition of this inner type is not relevant as +// it is used merely as a marker. It is common to use a using declaration of // `absl_nullability_compatible` set to void. // // // Example: @@ -150,14 +158,16 @@ #ifndef ABSL_BASE_NULLABILITY_H_ #define ABSL_BASE_NULLABILITY_H_ +#include "absl/base/config.h" #include "absl/base/internal/nullability_impl.h" namespace absl { +ABSL_NAMESPACE_BEGIN // absl::Nonnull // // The indicated pointer is never null. It is the responsibility of the provider -// of this pointer across an API boundary to ensure that the pointer is never be +// of this pointer across an API boundary to ensure that the pointer is never // set to null. Consumers of this pointer across an API boundary may safely // dereference the pointer. // @@ -198,9 +208,9 @@ using Nullable = nullability_internal::NullableImpl<T>; // migrated into one of the above two nullability states: `Nonnull<T>` or // `Nullable<T>`. // -// NOTE: Because this annotation is the global default state, pointers without -// any annotation are assumed to have "unknown" semantics. This assumption is -// designed to minimize churn and reduce clutter within the codebase. +// NOTE: Because this annotation is the global default state, unannotated +// pointers are assumed to have "unknown" semantics. This assumption is designed +// to minimize churn and reduce clutter within the codebase. // // Example: // @@ -219,6 +229,22 @@ using Nullable = nullability_internal::NullableImpl<T>; template <typename T> using NullabilityUnknown = nullability_internal::NullabilityUnknownImpl<T>; +ABSL_NAMESPACE_END } // namespace absl +// ABSL_NULLABILITY_COMPATIBLE +// +// Indicates that a class is compatible with nullability annotations. +// +// For example: +// +// struct ABSL_NULLABILITY_COMPATIBLE MyPtr { +// ... +// }; +#if ABSL_HAVE_FEATURE(nullability_on_classes) +#define ABSL_NULLABILITY_COMPATIBLE _Nullable +#else +#define ABSL_NULLABILITY_COMPATIBLE +#endif + #endif // ABSL_BASE_NULLABILITY_H_ |