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+// 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
+//
+// http://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_RAW_HASH_MAP_H_
+#define ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_
+
+#include <tuple>
+#include <type_traits>
+#include <utility>
+
+#include "absl/container/internal/container_memory.h"
+#include "absl/container/internal/raw_hash_set.h" // IWYU pragma: export
+
+namespace absl {
+inline namespace lts_2018_12_18 {
+namespace container_internal {
+
+template <class Policy, class Hash, class Eq, class Alloc>
+class raw_hash_map : public raw_hash_set<Policy, Hash, Eq, Alloc> {
+ // P is Policy. It's passed as a template argument to support maps that have
+ // incomplete types as values, as in unordered_map<K, IncompleteType>.
+ // MappedReference<> may be a non-reference type.
+ template <class P>
+ using MappedReference = decltype(P::value(
+ std::addressof(std::declval<typename raw_hash_map::reference>())));
+
+ // MappedConstReference<> may be a non-reference type.
+ template <class P>
+ using MappedConstReference = decltype(P::value(
+ std::addressof(std::declval<typename raw_hash_map::const_reference>())));
+
+ using KeyArgImpl = container_internal::KeyArg<IsTransparent<Eq>::value &&
+ IsTransparent<Hash>::value>;
+
+ public:
+ using key_type = typename Policy::key_type;
+ using mapped_type = typename Policy::mapped_type;
+ template <class K>
+ using key_arg = typename KeyArgImpl::template type<K, key_type>;
+
+ static_assert(!std::is_reference<key_type>::value, "");
+ // TODO(alkis): remove this assertion and verify that reference mapped_type is
+ // supported.
+ static_assert(!std::is_reference<mapped_type>::value, "");
+
+ using iterator = typename raw_hash_map::raw_hash_set::iterator;
+ using const_iterator = typename raw_hash_map::raw_hash_set::const_iterator;
+
+ raw_hash_map() {}
+ using raw_hash_map::raw_hash_set::raw_hash_set;
+
+ // The last two template parameters ensure that both arguments are rvalues
+ // (lvalue arguments are handled by the overloads below). This is necessary
+ // for supporting bitfield arguments.
+ //
+ // union { int n : 1; };
+ // flat_hash_map<int, int> m;
+ // m.insert_or_assign(n, n);
+ template <class K = key_type, class V = mapped_type, K* = nullptr,
+ V* = nullptr>
+ std::pair<iterator, bool> insert_or_assign(key_arg<K>&& k, V&& v) {
+ return insert_or_assign_impl(std::forward<K>(k), std::forward<V>(v));
+ }
+
+ template <class K = key_type, class V = mapped_type, K* = nullptr>
+ std::pair<iterator, bool> insert_or_assign(key_arg<K>&& k, const V& v) {
+ return insert_or_assign_impl(std::forward<K>(k), v);
+ }
+
+ template <class K = key_type, class V = mapped_type, V* = nullptr>
+ std::pair<iterator, bool> insert_or_assign(const key_arg<K>& k, V&& v) {
+ return insert_or_assign_impl(k, std::forward<V>(v));
+ }
+
+ template <class K = key_type, class V = mapped_type>
+ std::pair<iterator, bool> insert_or_assign(const key_arg<K>& k, const V& v) {
+ return insert_or_assign_impl(k, v);
+ }
+
+ template <class K = key_type, class V = mapped_type, K* = nullptr,
+ V* = nullptr>
+ iterator insert_or_assign(const_iterator, key_arg<K>&& k, V&& v) {
+ return insert_or_assign(std::forward<K>(k), std::forward<V>(v)).first;
+ }
+
+ template <class K = key_type, class V = mapped_type, K* = nullptr>
+ iterator insert_or_assign(const_iterator, key_arg<K>&& k, const V& v) {
+ return insert_or_assign(std::forward<K>(k), v).first;
+ }
+
+ template <class K = key_type, class V = mapped_type, V* = nullptr>
+ iterator insert_or_assign(const_iterator, const key_arg<K>& k, V&& v) {
+ return insert_or_assign(k, std::forward<V>(v)).first;
+ }
+
+ template <class K = key_type, class V = mapped_type>
+ iterator insert_or_assign(const_iterator, const key_arg<K>& k, const V& v) {
+ return insert_or_assign(k, v).first;
+ }
+
+ template <class K = key_type, class... Args,
+ typename std::enable_if<
+ !std::is_convertible<K, const_iterator>::value, int>::type = 0,
+ K* = nullptr>
+ std::pair<iterator, bool> try_emplace(key_arg<K>&& k, Args&&... args) {
+ return try_emplace_impl(std::forward<K>(k), std::forward<Args>(args)...);
+ }
+
+ template <class K = key_type, class... Args,
+ typename std::enable_if<
+ !std::is_convertible<K, const_iterator>::value, int>::type = 0>
+ std::pair<iterator, bool> try_emplace(const key_arg<K>& k, Args&&... args) {
+ return try_emplace_impl(k, std::forward<Args>(args)...);
+ }
+
+ template <class K = key_type, class... Args, K* = nullptr>
+ iterator try_emplace(const_iterator, key_arg<K>&& k, Args&&... args) {
+ return try_emplace(std::forward<K>(k), std::forward<Args>(args)...).first;
+ }
+
+ template <class K = key_type, class... Args>
+ iterator try_emplace(const_iterator, const key_arg<K>& k, Args&&... args) {
+ return try_emplace(k, std::forward<Args>(args)...).first;
+ }
+
+ template <class K = key_type, class P = Policy>
+ MappedReference<P> at(const key_arg<K>& key) {
+ auto it = this->find(key);
+ if (it == this->end()) std::abort();
+ return Policy::value(&*it);
+ }
+
+ template <class K = key_type, class P = Policy>
+ MappedConstReference<P> at(const key_arg<K>& key) const {
+ auto it = this->find(key);
+ if (it == this->end()) std::abort();
+ return Policy::value(&*it);
+ }
+
+ template <class K = key_type, class P = Policy, K* = nullptr>
+ MappedReference<P> operator[](key_arg<K>&& key) {
+ return Policy::value(&*try_emplace(std::forward<K>(key)).first);
+ }
+
+ template <class K = key_type, class P = Policy>
+ MappedReference<P> operator[](const key_arg<K>& key) {
+ return Policy::value(&*try_emplace(key).first);
+ }
+
+ private:
+ template <class K, class V>
+ std::pair<iterator, bool> insert_or_assign_impl(K&& k, V&& v) {
+ auto res = this->find_or_prepare_insert(k);
+ if (res.second)
+ this->emplace_at(res.first, std::forward<K>(k), std::forward<V>(v));
+ else
+ Policy::value(&*this->iterator_at(res.first)) = std::forward<V>(v);
+ return {this->iterator_at(res.first), res.second};
+ }
+
+ template <class K = key_type, class... Args>
+ std::pair<iterator, bool> try_emplace_impl(K&& k, Args&&... args) {
+ auto res = this->find_or_prepare_insert(k);
+ if (res.second)
+ this->emplace_at(res.first, std::piecewise_construct,
+ std::forward_as_tuple(std::forward<K>(k)),
+ std::forward_as_tuple(std::forward<Args>(args)...));
+ return {this->iterator_at(res.first), res.second};
+ }
+};
+
+} // namespace container_internal
+} // inline namespace lts_2018_12_18
+} // namespace absl
+
+#endif // ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_