chromium/third_party/abseil-cpp/absl/base/internal/nullability_impl.h

// Copyright 2023 The Abseil Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      https://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#ifndef ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_
#define ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_

#include <memory>
#include <type_traits>

#include "absl/base/attributes.h"
#include "absl/base/config.h"
#include "absl/meta/type_traits.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace nullability_internal {

// `IsNullabilityCompatible` checks whether its first argument is a class
// explicitly tagged as supporting nullability annotations. The tag is the type
// declaration `absl_nullability_compatible`.
template <typename, typename = void>
struct IsNullabilityCompatible : std::false_type { … };

IsNullabilityCompatible<T, absl::void_t<typename T::absl_nullability_compatible>>;

IsSupportedType;

IsSupportedType;

IsSupportedType;

IsSupportedType;

IsSupportedType;

template <typename T>
struct EnableNullable { … };

template <typename T>
struct EnableNonnull { … };

template <typename T>
struct EnableNullabilityUnknown { … };

// Note: we do not apply Clang nullability attributes (e.g. _Nullable).  These
// only support raw pointers, and conditionally enabling them only for raw
// pointers inhibits template arg deduction.  Ideally, they would support all
// pointer-like types.
NullableImpl;

NonnullImpl;

NullabilityUnknownImpl;

}  // namespace nullability_internal
ABSL_NAMESPACE_END
}  // namespace absl

#endif  // ABSL_BASE_INTERNAL_NULLABILITY_IMPL_H_