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Diffstat (limited to 'third_party/abseil_cpp/absl/container/internal/hash_policy_traits.h')
| -rw-r--r-- | third_party/abseil_cpp/absl/container/internal/hash_policy_traits.h | 191 |
1 files changed, 0 insertions, 191 deletions
diff --git a/third_party/abseil_cpp/absl/container/internal/hash_policy_traits.h b/third_party/abseil_cpp/absl/container/internal/hash_policy_traits.h deleted file mode 100644 index 3e1209c6eb..0000000000 --- a/third_party/abseil_cpp/absl/container/internal/hash_policy_traits.h +++ /dev/null @@ -1,191 +0,0 @@ -// 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. - -#ifndef ABSL_CONTAINER_INTERNAL_HASH_POLICY_TRAITS_H_ -#define ABSL_CONTAINER_INTERNAL_HASH_POLICY_TRAITS_H_ - -#include <cstddef> -#include <memory> -#include <type_traits> -#include <utility> - -#include "absl/meta/type_traits.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace container_internal { - -// Defines how slots are initialized/destroyed/moved. -template <class Policy, class = void> -struct hash_policy_traits { - private: - struct ReturnKey { - // We return `Key` here. - // When Key=T&, we forward the lvalue reference. - // When Key=T, we return by value to avoid a dangling reference. - // eg, for string_hash_map. - template <class Key, class... Args> - Key operator()(Key&& k, const Args&...) const { - return std::forward<Key>(k); - } - }; - - template <class P = Policy, class = void> - struct ConstantIteratorsImpl : std::false_type {}; - - template <class P> - struct ConstantIteratorsImpl<P, absl::void_t<typename P::constant_iterators>> - : P::constant_iterators {}; - - public: - // The actual object stored in the hash table. - using slot_type = typename Policy::slot_type; - - // The type of the keys stored in the hashtable. - using key_type = typename Policy::key_type; - - // The argument type for insertions into the hashtable. This is different - // from value_type for increased performance. See initializer_list constructor - // and insert() member functions for more details. - using init_type = typename Policy::init_type; - - using reference = decltype(Policy::element(std::declval<slot_type*>())); - using pointer = typename std::remove_reference<reference>::type*; - using value_type = typename std::remove_reference<reference>::type; - - // Policies can set this variable to tell raw_hash_set that all iterators - // should be constant, even `iterator`. This is useful for set-like - // containers. - // Defaults to false if not provided by the policy. - using constant_iterators = ConstantIteratorsImpl<>; - - // PRECONDITION: `slot` is UNINITIALIZED - // POSTCONDITION: `slot` is INITIALIZED - template <class Alloc, class... Args> - static void construct(Alloc* alloc, slot_type* slot, Args&&... args) { - Policy::construct(alloc, slot, std::forward<Args>(args)...); - } - - // PRECONDITION: `slot` is INITIALIZED - // POSTCONDITION: `slot` is UNINITIALIZED - template <class Alloc> - static void destroy(Alloc* alloc, slot_type* slot) { - Policy::destroy(alloc, slot); - } - - // Transfers the `old_slot` to `new_slot`. Any memory allocated by the - // allocator inside `old_slot` to `new_slot` can be transferred. - // - // OPTIONAL: defaults to: - // - // clone(new_slot, std::move(*old_slot)); - // destroy(old_slot); - // - // PRECONDITION: `new_slot` is UNINITIALIZED and `old_slot` is INITIALIZED - // POSTCONDITION: `new_slot` is INITIALIZED and `old_slot` is - // UNINITIALIZED - template <class Alloc> - static void transfer(Alloc* alloc, slot_type* new_slot, slot_type* old_slot) { - transfer_impl(alloc, new_slot, old_slot, 0); - } - - // PRECONDITION: `slot` is INITIALIZED - // POSTCONDITION: `slot` is INITIALIZED - template <class P = Policy> - static auto element(slot_type* slot) -> decltype(P::element(slot)) { - return P::element(slot); - } - - // Returns the amount of memory owned by `slot`, exclusive of `sizeof(*slot)`. - // - // If `slot` is nullptr, returns the constant amount of memory owned by any - // full slot or -1 if slots own variable amounts of memory. - // - // PRECONDITION: `slot` is INITIALIZED or nullptr - template <class P = Policy> - static size_t space_used(const slot_type* slot) { - return P::space_used(slot); - } - - // Provides generalized access to the key for elements, both for elements in - // the table and for elements that have not yet been inserted (or even - // constructed). We would like an API that allows us to say: `key(args...)` - // but we cannot do that for all cases, so we use this more general API that - // can be used for many things, including the following: - // - // - Given an element in a table, get its key. - // - Given an element initializer, get its key. - // - Given `emplace()` arguments, get the element key. - // - // Implementations of this must adhere to a very strict technical - // specification around aliasing and consuming arguments: - // - // Let `value_type` be the result type of `element()` without ref- and - // cv-qualifiers. The first argument is a functor, the rest are constructor - // arguments for `value_type`. Returns `std::forward<F>(f)(k, xs...)`, where - // `k` is the element key, and `xs...` are the new constructor arguments for - // `value_type`. It's allowed for `k` to alias `xs...`, and for both to alias - // `ts...`. The key won't be touched once `xs...` are used to construct an - // element; `ts...` won't be touched at all, which allows `apply()` to consume - // any rvalues among them. - // - // If `value_type` is constructible from `Ts&&...`, `Policy::apply()` must not - // trigger a hard compile error unless it originates from `f`. In other words, - // `Policy::apply()` must be SFINAE-friendly. If `value_type` is not - // constructible from `Ts&&...`, either SFINAE or a hard compile error is OK. - // - // If `Ts...` is `[cv] value_type[&]` or `[cv] init_type[&]`, - // `Policy::apply()` must work. A compile error is not allowed, SFINAE or not. - template <class F, class... Ts, class P = Policy> - static auto apply(F&& f, Ts&&... ts) - -> decltype(P::apply(std::forward<F>(f), std::forward<Ts>(ts)...)) { - return P::apply(std::forward<F>(f), std::forward<Ts>(ts)...); - } - - // Returns the "key" portion of the slot. - // Used for node handle manipulation. - template <class P = Policy> - static auto key(slot_type* slot) - -> decltype(P::apply(ReturnKey(), element(slot))) { - return P::apply(ReturnKey(), element(slot)); - } - - // Returns the "value" (as opposed to the "key") portion of the element. Used - // by maps to implement `operator[]`, `at()` and `insert_or_assign()`. - template <class T, class P = Policy> - static auto value(T* elem) -> decltype(P::value(elem)) { - return P::value(elem); - } - - private: - // Use auto -> decltype as an enabler. - template <class Alloc, class P = Policy> - static auto transfer_impl(Alloc* alloc, slot_type* new_slot, - slot_type* old_slot, int) - -> decltype((void)P::transfer(alloc, new_slot, old_slot)) { - P::transfer(alloc, new_slot, old_slot); - } - template <class Alloc> - static void transfer_impl(Alloc* alloc, slot_type* new_slot, - slot_type* old_slot, char) { - construct(alloc, new_slot, std::move(element(old_slot))); - destroy(alloc, old_slot); - } -}; - -} // namespace container_internal -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_CONTAINER_INTERNAL_HASH_POLICY_TRAITS_H_ |