chromium/third_party/abseil-cpp/absl/container/internal/hash_policy_testing.h

// Copyright 2018 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.
//
// Utilities to help tests verify that hash tables properly handle stateful
// allocators and hash functions.

#ifndef ABSL_CONTAINER_INTERNAL_HASH_POLICY_TESTING_H_
#define ABSL_CONTAINER_INTERNAL_HASH_POLICY_TESTING_H_

#include <cstdlib>
#include <limits>
#include <memory>
#include <ostream>
#include <type_traits>
#include <utility>
#include <vector>

#include "absl/hash/hash.h"
#include "absl/strings/string_view.h"

namespace absl {
ABSL_NAMESPACE_BEGIN
namespace container_internal {
namespace hash_testing_internal {

template <class Derived>
struct WithId {};

}  // namespace hash_testing_internal

struct NonStandardLayout {};

struct StatefulTestingHash
    : absl::container_internal::hash_testing_internal::WithId<
          StatefulTestingHash> {};

struct StatefulTestingEqual
    : absl::container_internal::hash_testing_internal::WithId<
          StatefulTestingEqual> {};

// It is expected that Alloc() == Alloc() for all allocators so we cannot use
// WithId base. We need to explicitly assign ids.
template <class T = int>
struct Alloc : std::allocator<T> {};

template <class Map>
auto items(const Map& m) -> std::vector<
    std::pair<typename Map::key_type, typename Map::mapped_type>> {}

template <class Set>
auto keys(const Set& s)
    -> std::vector<typename std::decay<typename Set::key_type>::type> {}

}  // namespace container_internal
ABSL_NAMESPACE_END
}  // namespace absl

// ABSL_UNORDERED_SUPPORTS_ALLOC_CTORS is false for glibcxx versions
// where the unordered containers are missing certain constructors that
// take allocator arguments. This test is defined ad-hoc for the platforms
// we care about (notably Crosstool 17) because libstdcxx's useless
// versioning scheme precludes a more principled solution.
// From GCC-4.9 Changelog: (src: https://gcc.gnu.org/gcc-4.9/changes.html)
// "the unordered associative containers in <unordered_map> and <unordered_set>
// meet the allocator-aware container requirements;"
#if defined(__GLIBCXX__) && __GLIBCXX__ <= 20140425
#define ABSL_UNORDERED_SUPPORTS_ALLOC_CTORS
#else
#define ABSL_UNORDERED_SUPPORTS_ALLOC_CTORS
#endif

#endif  // ABSL_CONTAINER_INTERNAL_HASH_POLICY_TESTING_H_