185 lines
		
	
	
	
		
			7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
			
		
		
	
	
			185 lines
		
	
	
	
		
			7 KiB
		
	
	
	
		
			C++
		
	
	
	
	
	
| // Copyright 2018 The Abseil Authors.
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| //
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| // Licensed under the Apache License, Version 2.0 (the "License");
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| // you may not use this file except in compliance with the License.
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| // You may obtain a copy of the License at
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| //
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| //      http://www.apache.org/licenses/LICENSE-2.0
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| //
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| // Unless required by applicable law or agreed to in writing, software
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| // distributed under the License is distributed on an "AS IS" BASIS,
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| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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| // See the License for the specific language governing permissions and
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| // limitations under the License.
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| 
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| #ifndef ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_
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| #define ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_
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| 
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| #include <tuple>
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| #include <type_traits>
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| #include <utility>
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| 
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| #include "absl/container/internal/container_memory.h"
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| #include "absl/container/internal/raw_hash_set.h"  // IWYU pragma: export
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| 
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| namespace absl {
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| namespace container_internal {
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| 
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| template <class Policy, class Hash, class Eq, class Alloc>
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| class raw_hash_map : public raw_hash_set<Policy, Hash, Eq, Alloc> {
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|   // P is Policy. It's passed as a template argument to support maps that have
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|   // incomplete types as values, as in unordered_map<K, IncompleteType>.
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|   // MappedReference<> may be a non-reference type.
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|   template <class P>
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|   using MappedReference = decltype(P::value(
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|       std::addressof(std::declval<typename raw_hash_map::reference>())));
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| 
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|   // MappedConstReference<> may be a non-reference type.
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|   template <class P>
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|   using MappedConstReference = decltype(P::value(
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|       std::addressof(std::declval<typename raw_hash_map::const_reference>())));
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| 
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|   using KeyArgImpl = container_internal::KeyArg<IsTransparent<Eq>::value &&
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|                                                 IsTransparent<Hash>::value>;
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| 
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|  public:
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|   using key_type = typename Policy::key_type;
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|   using mapped_type = typename Policy::mapped_type;
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|   template <class K>
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|   using key_arg = typename KeyArgImpl::template type<K, key_type>;
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| 
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|   static_assert(!std::is_reference<key_type>::value, "");
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|   // TODO(alkis): remove this assertion and verify that reference mapped_type is
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|   // supported.
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|   static_assert(!std::is_reference<mapped_type>::value, "");
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| 
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|   using iterator = typename raw_hash_map::raw_hash_set::iterator;
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|   using const_iterator = typename raw_hash_map::raw_hash_set::const_iterator;
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| 
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|   raw_hash_map() {}
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|   using raw_hash_map::raw_hash_set::raw_hash_set;
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| 
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|   // The last two template parameters ensure that both arguments are rvalues
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|   // (lvalue arguments are handled by the overloads below). This is necessary
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|   // for supporting bitfield arguments.
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|   //
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|   //   union { int n : 1; };
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|   //   flat_hash_map<int, int> m;
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|   //   m.insert_or_assign(n, n);
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|   template <class K = key_type, class V = mapped_type, K* = nullptr,
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|             V* = nullptr>
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|   std::pair<iterator, bool> insert_or_assign(key_arg<K>&& k, V&& v) {
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|     return insert_or_assign_impl(std::forward<K>(k), std::forward<V>(v));
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|   }
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| 
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|   template <class K = key_type, class V = mapped_type, K* = nullptr>
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|   std::pair<iterator, bool> insert_or_assign(key_arg<K>&& k, const V& v) {
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|     return insert_or_assign_impl(std::forward<K>(k), v);
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|   }
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| 
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|   template <class K = key_type, class V = mapped_type, V* = nullptr>
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|   std::pair<iterator, bool> insert_or_assign(const key_arg<K>& k, V&& v) {
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|     return insert_or_assign_impl(k, std::forward<V>(v));
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|   }
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| 
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|   template <class K = key_type, class V = mapped_type>
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|   std::pair<iterator, bool> insert_or_assign(const key_arg<K>& k, const V& v) {
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|     return insert_or_assign_impl(k, v);
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|   }
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| 
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|   template <class K = key_type, class V = mapped_type, K* = nullptr,
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|             V* = nullptr>
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|   iterator insert_or_assign(const_iterator, key_arg<K>&& k, V&& v) {
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|     return insert_or_assign(std::forward<K>(k), std::forward<V>(v)).first;
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|   }
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| 
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|   template <class K = key_type, class V = mapped_type, K* = nullptr>
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|   iterator insert_or_assign(const_iterator, key_arg<K>&& k, const V& v) {
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|     return insert_or_assign(std::forward<K>(k), v).first;
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|   }
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| 
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|   template <class K = key_type, class V = mapped_type, V* = nullptr>
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|   iterator insert_or_assign(const_iterator, const key_arg<K>& k, V&& v) {
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|     return insert_or_assign(k, std::forward<V>(v)).first;
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|   }
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| 
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|   template <class K = key_type, class V = mapped_type>
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|   iterator insert_or_assign(const_iterator, const key_arg<K>& k, const V& v) {
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|     return insert_or_assign(k, v).first;
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|   }
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| 
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|   template <class K = key_type, class... Args,
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|             typename std::enable_if<
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|                 !std::is_convertible<K, const_iterator>::value, int>::type = 0,
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|             K* = nullptr>
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|   std::pair<iterator, bool> try_emplace(key_arg<K>&& k, Args&&... args) {
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|     return try_emplace_impl(std::forward<K>(k), std::forward<Args>(args)...);
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|   }
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| 
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|   template <class K = key_type, class... Args,
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|             typename std::enable_if<
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|                 !std::is_convertible<K, const_iterator>::value, int>::type = 0>
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|   std::pair<iterator, bool> try_emplace(const key_arg<K>& k, Args&&... args) {
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|     return try_emplace_impl(k, std::forward<Args>(args)...);
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|   }
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| 
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|   template <class K = key_type, class... Args, K* = nullptr>
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|   iterator try_emplace(const_iterator, key_arg<K>&& k, Args&&... args) {
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|     return try_emplace(std::forward<K>(k), std::forward<Args>(args)...).first;
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|   }
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| 
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|   template <class K = key_type, class... Args>
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|   iterator try_emplace(const_iterator, const key_arg<K>& k, Args&&... args) {
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|     return try_emplace(k, std::forward<Args>(args)...).first;
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|   }
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| 
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|   template <class K = key_type, class P = Policy>
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|   MappedReference<P> at(const key_arg<K>& key) {
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|     auto it = this->find(key);
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|     if (it == this->end()) std::abort();
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|     return Policy::value(&*it);
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|   }
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| 
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|   template <class K = key_type, class P = Policy>
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|   MappedConstReference<P> at(const key_arg<K>& key) const {
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|     auto it = this->find(key);
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|     if (it == this->end()) std::abort();
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|     return Policy::value(&*it);
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|   }
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| 
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|   template <class K = key_type, class P = Policy, K* = nullptr>
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|   MappedReference<P> operator[](key_arg<K>&& key) {
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|     return Policy::value(&*try_emplace(std::forward<K>(key)).first);
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|   }
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| 
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|   template <class K = key_type, class P = Policy>
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|   MappedReference<P> operator[](const key_arg<K>& key) {
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|     return Policy::value(&*try_emplace(key).first);
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|   }
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| 
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|  private:
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|   template <class K, class V>
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|   std::pair<iterator, bool> insert_or_assign_impl(K&& k, V&& v) {
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|     auto res = this->find_or_prepare_insert(k);
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|     if (res.second)
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|       this->emplace_at(res.first, std::forward<K>(k), std::forward<V>(v));
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|     else
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|       Policy::value(&*this->iterator_at(res.first)) = std::forward<V>(v);
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|     return {this->iterator_at(res.first), res.second};
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|   }
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| 
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|   template <class K = key_type, class... Args>
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|   std::pair<iterator, bool> try_emplace_impl(K&& k, Args&&... args) {
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|     auto res = this->find_or_prepare_insert(k);
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|     if (res.second)
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|       this->emplace_at(res.first, std::piecewise_construct,
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|                        std::forward_as_tuple(std::forward<K>(k)),
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|                        std::forward_as_tuple(std::forward<Args>(args)...));
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|     return {this->iterator_at(res.first), res.second};
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|   }
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| };
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| 
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| }  // namespace container_internal
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| }  // namespace absl
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| 
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| #endif  // ABSL_CONTAINER_INTERNAL_RAW_HASH_MAP_H_
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