summaryrefslogtreecommitdiff
path: root/absl/container/internal/btree_container.h
diff options
context:
space:
mode:
Diffstat (limited to 'absl/container/internal/btree_container.h')
-rw-r--r--absl/container/internal/btree_container.h672
1 files changed, 672 insertions, 0 deletions
diff --git a/absl/container/internal/btree_container.h b/absl/container/internal/btree_container.h
new file mode 100644
index 00000000..f2e4c3a5
--- /dev/null
+++ b/absl/container/internal/btree_container.h
@@ -0,0 +1,672 @@
+// 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_BTREE_CONTAINER_H_
+#define ABSL_CONTAINER_INTERNAL_BTREE_CONTAINER_H_
+
+#include <algorithm>
+#include <initializer_list>
+#include <iterator>
+#include <utility>
+
+#include "absl/base/internal/throw_delegate.h"
+#include "absl/container/internal/btree.h" // IWYU pragma: export
+#include "absl/container/internal/common.h"
+#include "absl/meta/type_traits.h"
+
+namespace absl {
+ABSL_NAMESPACE_BEGIN
+namespace container_internal {
+
+// A common base class for btree_set, btree_map, btree_multiset, and
+// btree_multimap.
+template <typename Tree>
+class btree_container {
+ using params_type = typename Tree::params_type;
+
+ protected:
+ // Alias used for heterogeneous lookup functions.
+ // `key_arg<K>` evaluates to `K` when the functors are transparent and to
+ // `key_type` otherwise. It permits template argument deduction on `K` for the
+ // transparent case.
+ template <class K>
+ using key_arg =
+ typename KeyArg<IsTransparent<typename Tree::key_compare>::value>::
+ template type<K, typename Tree::key_type>;
+
+ public:
+ using key_type = typename Tree::key_type;
+ using value_type = typename Tree::value_type;
+ using size_type = typename Tree::size_type;
+ using difference_type = typename Tree::difference_type;
+ using key_compare = typename Tree::key_compare;
+ using value_compare = typename Tree::value_compare;
+ using allocator_type = typename Tree::allocator_type;
+ using reference = typename Tree::reference;
+ using const_reference = typename Tree::const_reference;
+ using pointer = typename Tree::pointer;
+ using const_pointer = typename Tree::const_pointer;
+ using iterator = typename Tree::iterator;
+ using const_iterator = typename Tree::const_iterator;
+ using reverse_iterator = typename Tree::reverse_iterator;
+ using const_reverse_iterator = typename Tree::const_reverse_iterator;
+ using node_type = typename Tree::node_handle_type;
+
+ // Constructors/assignments.
+ btree_container() : tree_(key_compare(), allocator_type()) {}
+ explicit btree_container(const key_compare &comp,
+ const allocator_type &alloc = allocator_type())
+ : tree_(comp, alloc) {}
+ btree_container(const btree_container &x) = default;
+ btree_container(btree_container &&x) noexcept = default;
+ btree_container &operator=(const btree_container &x) = default;
+ btree_container &operator=(btree_container &&x) noexcept(
+ std::is_nothrow_move_assignable<Tree>::value) = default;
+
+ // Iterator routines.
+ iterator begin() { return tree_.begin(); }
+ const_iterator begin() const { return tree_.begin(); }
+ const_iterator cbegin() const { return tree_.begin(); }
+ iterator end() { return tree_.end(); }
+ const_iterator end() const { return tree_.end(); }
+ const_iterator cend() const { return tree_.end(); }
+ reverse_iterator rbegin() { return tree_.rbegin(); }
+ const_reverse_iterator rbegin() const { return tree_.rbegin(); }
+ const_reverse_iterator crbegin() const { return tree_.rbegin(); }
+ reverse_iterator rend() { return tree_.rend(); }
+ const_reverse_iterator rend() const { return tree_.rend(); }
+ const_reverse_iterator crend() const { return tree_.rend(); }
+
+ // Lookup routines.
+ template <typename K = key_type>
+ iterator find(const key_arg<K> &key) {
+ return tree_.find(key);
+ }
+ template <typename K = key_type>
+ const_iterator find(const key_arg<K> &key) const {
+ return tree_.find(key);
+ }
+ template <typename K = key_type>
+ bool contains(const key_arg<K> &key) const {
+ return find(key) != end();
+ }
+ template <typename K = key_type>
+ iterator lower_bound(const key_arg<K> &key) {
+ return tree_.lower_bound(key);
+ }
+ template <typename K = key_type>
+ const_iterator lower_bound(const key_arg<K> &key) const {
+ return tree_.lower_bound(key);
+ }
+ template <typename K = key_type>
+ iterator upper_bound(const key_arg<K> &key) {
+ return tree_.upper_bound(key);
+ }
+ template <typename K = key_type>
+ const_iterator upper_bound(const key_arg<K> &key) const {
+ return tree_.upper_bound(key);
+ }
+ template <typename K = key_type>
+ std::pair<iterator, iterator> equal_range(const key_arg<K> &key) {
+ return tree_.equal_range(key);
+ }
+ template <typename K = key_type>
+ std::pair<const_iterator, const_iterator> equal_range(
+ const key_arg<K> &key) const {
+ return tree_.equal_range(key);
+ }
+
+ // Deletion routines. Note that there is also a deletion routine that is
+ // specific to btree_set_container/btree_multiset_container.
+
+ // Erase the specified iterator from the btree. The iterator must be valid
+ // (i.e. not equal to end()). Return an iterator pointing to the node after
+ // the one that was erased (or end() if none exists).
+ iterator erase(const_iterator iter) { return tree_.erase(iterator(iter)); }
+ iterator erase(iterator iter) { return tree_.erase(iter); }
+ iterator erase(const_iterator first, const_iterator last) {
+ return tree_.erase_range(iterator(first), iterator(last)).second;
+ }
+
+ // Extract routines.
+ node_type extract(iterator position) {
+ // Use Move instead of Transfer, because the rebalancing code expects to
+ // have a valid object to scribble metadata bits on top of.
+ auto node = CommonAccess::Move<node_type>(get_allocator(), position.slot());
+ erase(position);
+ return node;
+ }
+ node_type extract(const_iterator position) {
+ return extract(iterator(position));
+ }
+
+ public:
+ // Utility routines.
+ void clear() { tree_.clear(); }
+ void swap(btree_container &x) { tree_.swap(x.tree_); }
+ void verify() const { tree_.verify(); }
+
+ // Size routines.
+ size_type size() const { return tree_.size(); }
+ size_type max_size() const { return tree_.max_size(); }
+ bool empty() const { return tree_.empty(); }
+
+ friend bool operator==(const btree_container &x, const btree_container &y) {
+ if (x.size() != y.size()) return false;
+ return std::equal(x.begin(), x.end(), y.begin());
+ }
+
+ friend bool operator!=(const btree_container &x, const btree_container &y) {
+ return !(x == y);
+ }
+
+ friend bool operator<(const btree_container &x, const btree_container &y) {
+ return std::lexicographical_compare(x.begin(), x.end(), y.begin(), y.end());
+ }
+
+ friend bool operator>(const btree_container &x, const btree_container &y) {
+ return y < x;
+ }
+
+ friend bool operator<=(const btree_container &x, const btree_container &y) {
+ return !(y < x);
+ }
+
+ friend bool operator>=(const btree_container &x, const btree_container &y) {
+ return !(x < y);
+ }
+
+ // The allocator used by the btree.
+ allocator_type get_allocator() const { return tree_.get_allocator(); }
+
+ // The key comparator used by the btree.
+ key_compare key_comp() const { return tree_.key_comp(); }
+ value_compare value_comp() const { return tree_.value_comp(); }
+
+ // Support absl::Hash.
+ template <typename State>
+ friend State AbslHashValue(State h, const btree_container &b) {
+ for (const auto &v : b) {
+ h = State::combine(std::move(h), v);
+ }
+ return State::combine(std::move(h), b.size());
+ }
+
+ protected:
+ Tree tree_;
+};
+
+// A common base class for btree_set and btree_map.
+template <typename Tree>
+class btree_set_container : public btree_container<Tree> {
+ using super_type = btree_container<Tree>;
+ using params_type = typename Tree::params_type;
+ using init_type = typename params_type::init_type;
+ using is_key_compare_to = typename params_type::is_key_compare_to;
+ friend class BtreeNodePeer;
+
+ protected:
+ template <class K>
+ using key_arg = typename super_type::template key_arg<K>;
+
+ public:
+ using key_type = typename Tree::key_type;
+ using value_type = typename Tree::value_type;
+ using size_type = typename Tree::size_type;
+ using key_compare = typename Tree::key_compare;
+ using allocator_type = typename Tree::allocator_type;
+ using iterator = typename Tree::iterator;
+ using const_iterator = typename Tree::const_iterator;
+ using node_type = typename super_type::node_type;
+ using insert_return_type = InsertReturnType<iterator, node_type>;
+
+ // Inherit constructors.
+ using super_type::super_type;
+ btree_set_container() {}
+
+ // Range constructor.
+ template <class InputIterator>
+ btree_set_container(InputIterator b, InputIterator e,
+ const key_compare &comp = key_compare(),
+ const allocator_type &alloc = allocator_type())
+ : super_type(comp, alloc) {
+ insert(b, e);
+ }
+
+ // Initializer list constructor.
+ btree_set_container(std::initializer_list<init_type> init,
+ const key_compare &comp = key_compare(),
+ const allocator_type &alloc = allocator_type())
+ : btree_set_container(init.begin(), init.end(), comp, alloc) {}
+
+ // Lookup routines.
+ template <typename K = key_type>
+ size_type count(const key_arg<K> &key) const {
+ return this->tree_.count_unique(key);
+ }
+
+ // Insertion routines.
+ std::pair<iterator, bool> insert(const value_type &x) {
+ return this->tree_.insert_unique(params_type::key(x), x);
+ }
+ std::pair<iterator, bool> insert(value_type &&x) {
+ return this->tree_.insert_unique(params_type::key(x), std::move(x));
+ }
+ template <typename... Args>
+ std::pair<iterator, bool> emplace(Args &&... args) {
+ init_type v(std::forward<Args>(args)...);
+ return this->tree_.insert_unique(params_type::key(v), std::move(v));
+ }
+ iterator insert(const_iterator position, const value_type &x) {
+ return this->tree_
+ .insert_hint_unique(iterator(position), params_type::key(x), x)
+ .first;
+ }
+ iterator insert(const_iterator position, value_type &&x) {
+ return this->tree_
+ .insert_hint_unique(iterator(position), params_type::key(x),
+ std::move(x))
+ .first;
+ }
+ template <typename... Args>
+ iterator emplace_hint(const_iterator position, Args &&... args) {
+ init_type v(std::forward<Args>(args)...);
+ return this->tree_
+ .insert_hint_unique(iterator(position), params_type::key(v),
+ std::move(v))
+ .first;
+ }
+ template <typename InputIterator>
+ void insert(InputIterator b, InputIterator e) {
+ this->tree_.insert_iterator_unique(b, e);
+ }
+ void insert(std::initializer_list<init_type> init) {
+ this->tree_.insert_iterator_unique(init.begin(), init.end());
+ }
+ insert_return_type insert(node_type &&node) {
+ if (!node) return {this->end(), false, node_type()};
+ std::pair<iterator, bool> res =
+ this->tree_.insert_unique(params_type::key(CommonAccess::GetSlot(node)),
+ CommonAccess::GetSlot(node));
+ if (res.second) {
+ CommonAccess::Destroy(&node);
+ return {res.first, true, node_type()};
+ } else {
+ return {res.first, false, std::move(node)};
+ }
+ }
+ iterator insert(const_iterator hint, node_type &&node) {
+ if (!node) return this->end();
+ std::pair<iterator, bool> res = this->tree_.insert_hint_unique(
+ iterator(hint), params_type::key(CommonAccess::GetSlot(node)),
+ CommonAccess::GetSlot(node));
+ if (res.second) CommonAccess::Destroy(&node);
+ return res.first;
+ }
+
+ // Deletion routines.
+ template <typename K = key_type>
+ size_type erase(const key_arg<K> &key) {
+ return this->tree_.erase_unique(key);
+ }
+ using super_type::erase;
+
+ // Node extraction routines.
+ template <typename K = key_type>
+ node_type extract(const key_arg<K> &key) {
+ auto it = this->find(key);
+ return it == this->end() ? node_type() : extract(it);
+ }
+ using super_type::extract;
+
+ // Merge routines.
+ // Moves elements from `src` into `this`. If the element already exists in
+ // `this`, it is left unmodified in `src`.
+ template <
+ typename T,
+ typename absl::enable_if_t<
+ absl::conjunction<
+ std::is_same<value_type, typename T::value_type>,
+ std::is_same<allocator_type, typename T::allocator_type>,
+ std::is_same<typename params_type::is_map_container,
+ typename T::params_type::is_map_container>>::value,
+ int> = 0>
+ void merge(btree_container<T> &src) { // NOLINT
+ for (auto src_it = src.begin(); src_it != src.end();) {
+ if (insert(std::move(*src_it)).second) {
+ src_it = src.erase(src_it);
+ } else {
+ ++src_it;
+ }
+ }
+ }
+
+ template <
+ typename T,
+ typename absl::enable_if_t<
+ absl::conjunction<
+ std::is_same<value_type, typename T::value_type>,
+ std::is_same<allocator_type, typename T::allocator_type>,
+ std::is_same<typename params_type::is_map_container,
+ typename T::params_type::is_map_container>>::value,
+ int> = 0>
+ void merge(btree_container<T> &&src) {
+ merge(src);
+ }
+};
+
+// Base class for btree_map.
+template <typename Tree>
+class btree_map_container : public btree_set_container<Tree> {
+ using super_type = btree_set_container<Tree>;
+ using params_type = typename Tree::params_type;
+
+ private:
+ template <class K>
+ using key_arg = typename super_type::template key_arg<K>;
+
+ public:
+ using key_type = typename Tree::key_type;
+ using mapped_type = typename params_type::mapped_type;
+ using value_type = typename Tree::value_type;
+ using key_compare = typename Tree::key_compare;
+ using allocator_type = typename Tree::allocator_type;
+ using iterator = typename Tree::iterator;
+ using const_iterator = typename Tree::const_iterator;
+
+ // Inherit constructors.
+ using super_type::super_type;
+ btree_map_container() {}
+
+ // Insertion routines.
+ // Note: the nullptr template arguments and extra `const M&` overloads allow
+ // for supporting bitfield arguments.
+ // Note: when we call `std::forward<M>(obj)` twice, it's safe because
+ // insert_unique/insert_hint_unique are guaranteed to not consume `obj` when
+ // `ret.second` is false.
+ template <class M>
+ std::pair<iterator, bool> insert_or_assign(const key_type &k, const M &obj) {
+ const std::pair<iterator, bool> ret = this->tree_.insert_unique(k, k, obj);
+ if (!ret.second) ret.first->second = obj;
+ return ret;
+ }
+ template <class M, key_type * = nullptr>
+ std::pair<iterator, bool> insert_or_assign(key_type &&k, const M &obj) {
+ const std::pair<iterator, bool> ret =
+ this->tree_.insert_unique(k, std::move(k), obj);
+ if (!ret.second) ret.first->second = obj;
+ return ret;
+ }
+ template <class M, M * = nullptr>
+ std::pair<iterator, bool> insert_or_assign(const key_type &k, M &&obj) {
+ const std::pair<iterator, bool> ret =
+ this->tree_.insert_unique(k, k, std::forward<M>(obj));
+ if (!ret.second) ret.first->second = std::forward<M>(obj);
+ return ret;
+ }
+ template <class M, key_type * = nullptr, M * = nullptr>
+ std::pair<iterator, bool> insert_or_assign(key_type &&k, M &&obj) {
+ const std::pair<iterator, bool> ret =
+ this->tree_.insert_unique(k, std::move(k), std::forward<M>(obj));
+ if (!ret.second) ret.first->second = std::forward<M>(obj);
+ return ret;
+ }
+ template <class M>
+ iterator insert_or_assign(const_iterator position, const key_type &k,
+ const M &obj) {
+ const std::pair<iterator, bool> ret =
+ this->tree_.insert_hint_unique(iterator(position), k, k, obj);
+ if (!ret.second) ret.first->second = obj;
+ return ret.first;
+ }
+ template <class M, key_type * = nullptr>
+ iterator insert_or_assign(const_iterator position, key_type &&k,
+ const M &obj) {
+ const std::pair<iterator, bool> ret = this->tree_.insert_hint_unique(
+ iterator(position), k, std::move(k), obj);
+ if (!ret.second) ret.first->second = obj;
+ return ret.first;
+ }
+ template <class M, M * = nullptr>
+ iterator insert_or_assign(const_iterator position, const key_type &k,
+ M &&obj) {
+ const std::pair<iterator, bool> ret = this->tree_.insert_hint_unique(
+ iterator(position), k, k, std::forward<M>(obj));
+ if (!ret.second) ret.first->second = std::forward<M>(obj);
+ return ret.first;
+ }
+ template <class M, key_type * = nullptr, M * = nullptr>
+ iterator insert_or_assign(const_iterator position, key_type &&k, M &&obj) {
+ const std::pair<iterator, bool> ret = this->tree_.insert_hint_unique(
+ iterator(position), k, std::move(k), std::forward<M>(obj));
+ if (!ret.second) ret.first->second = std::forward<M>(obj);
+ return ret.first;
+ }
+ template <typename... Args>
+ std::pair<iterator, bool> try_emplace(const key_type &k, Args &&... args) {
+ return this->tree_.insert_unique(
+ k, std::piecewise_construct, std::forward_as_tuple(k),
+ std::forward_as_tuple(std::forward<Args>(args)...));
+ }
+ template <typename... Args>
+ std::pair<iterator, bool> try_emplace(key_type &&k, Args &&... args) {
+ // Note: `key_ref` exists to avoid a ClangTidy warning about moving from `k`
+ // and then using `k` unsequenced. This is safe because the move is into a
+ // forwarding reference and insert_unique guarantees that `key` is never
+ // referenced after consuming `args`.
+ const key_type &key_ref = k;
+ return this->tree_.insert_unique(
+ key_ref, std::piecewise_construct, std::forward_as_tuple(std::move(k)),
+ std::forward_as_tuple(std::forward<Args>(args)...));
+ }
+ template <typename... Args>
+ iterator try_emplace(const_iterator hint, const key_type &k,
+ Args &&... args) {
+ return this->tree_
+ .insert_hint_unique(iterator(hint), k, std::piecewise_construct,
+ std::forward_as_tuple(k),
+ std::forward_as_tuple(std::forward<Args>(args)...))
+ .first;
+ }
+ template <typename... Args>
+ iterator try_emplace(const_iterator hint, key_type &&k, Args &&... args) {
+ // Note: `key_ref` exists to avoid a ClangTidy warning about moving from `k`
+ // and then using `k` unsequenced. This is safe because the move is into a
+ // forwarding reference and insert_hint_unique guarantees that `key` is
+ // never referenced after consuming `args`.
+ const key_type &key_ref = k;
+ return this->tree_
+ .insert_hint_unique(iterator(hint), key_ref, std::piecewise_construct,
+ std::forward_as_tuple(std::move(k)),
+ std::forward_as_tuple(std::forward<Args>(args)...))
+ .first;
+ }
+ mapped_type &operator[](const key_type &k) {
+ return try_emplace(k).first->second;
+ }
+ mapped_type &operator[](key_type &&k) {
+ return try_emplace(std::move(k)).first->second;
+ }
+
+ template <typename K = key_type>
+ mapped_type &at(const key_arg<K> &key) {
+ auto it = this->find(key);
+ if (it == this->end())
+ base_internal::ThrowStdOutOfRange("absl::btree_map::at");
+ return it->second;
+ }
+ template <typename K = key_type>
+ const mapped_type &at(const key_arg<K> &key) const {
+ auto it = this->find(key);
+ if (it == this->end())
+ base_internal::ThrowStdOutOfRange("absl::btree_map::at");
+ return it->second;
+ }
+};
+
+// A common base class for btree_multiset and btree_multimap.
+template <typename Tree>
+class btree_multiset_container : public btree_container<Tree> {
+ using super_type = btree_container<Tree>;
+ using params_type = typename Tree::params_type;
+ using init_type = typename params_type::init_type;
+ using is_key_compare_to = typename params_type::is_key_compare_to;
+
+ template <class K>
+ using key_arg = typename super_type::template key_arg<K>;
+
+ public:
+ using key_type = typename Tree::key_type;
+ using value_type = typename Tree::value_type;
+ using size_type = typename Tree::size_type;
+ using key_compare = typename Tree::key_compare;
+ using allocator_type = typename Tree::allocator_type;
+ using iterator = typename Tree::iterator;
+ using const_iterator = typename Tree::const_iterator;
+ using node_type = typename super_type::node_type;
+
+ // Inherit constructors.
+ using super_type::super_type;
+ btree_multiset_container() {}
+
+ // Range constructor.
+ template <class InputIterator>
+ btree_multiset_container(InputIterator b, InputIterator e,
+ const key_compare &comp = key_compare(),
+ const allocator_type &alloc = allocator_type())
+ : super_type(comp, alloc) {
+ insert(b, e);
+ }
+
+ // Initializer list constructor.
+ btree_multiset_container(std::initializer_list<init_type> init,
+ const key_compare &comp = key_compare(),
+ const allocator_type &alloc = allocator_type())
+ : btree_multiset_container(init.begin(), init.end(), comp, alloc) {}
+
+ // Lookup routines.
+ template <typename K = key_type>
+ size_type count(const key_arg<K> &key) const {
+ return this->tree_.count_multi(key);
+ }
+
+ // Insertion routines.
+ iterator insert(const value_type &x) { return this->tree_.insert_multi(x); }
+ iterator insert(value_type &&x) {
+ return this->tree_.insert_multi(std::move(x));
+ }
+ iterator insert(const_iterator position, const value_type &x) {
+ return this->tree_.insert_hint_multi(iterator(position), x);
+ }
+ iterator insert(const_iterator position, value_type &&x) {
+ return this->tree_.insert_hint_multi(iterator(position), std::move(x));
+ }
+ template <typename InputIterator>
+ void insert(InputIterator b, InputIterator e) {
+ this->tree_.insert_iterator_multi(b, e);
+ }
+ void insert(std::initializer_list<init_type> init) {
+ this->tree_.insert_iterator_multi(init.begin(), init.end());
+ }
+ template <typename... Args>
+ iterator emplace(Args &&... args) {
+ return this->tree_.insert_multi(init_type(std::forward<Args>(args)...));
+ }
+ template <typename... Args>
+ iterator emplace_hint(const_iterator position, Args &&... args) {
+ return this->tree_.insert_hint_multi(
+ iterator(position), init_type(std::forward<Args>(args)...));
+ }
+ iterator insert(node_type &&node) {
+ if (!node) return this->end();
+ iterator res =
+ this->tree_.insert_multi(params_type::key(CommonAccess::GetSlot(node)),
+ CommonAccess::GetSlot(node));
+ CommonAccess::Destroy(&node);
+ return res;
+ }
+ iterator insert(const_iterator hint, node_type &&node) {
+ if (!node) return this->end();
+ iterator res = this->tree_.insert_hint_multi(
+ iterator(hint),
+ std::move(params_type::element(CommonAccess::GetSlot(node))));
+ CommonAccess::Destroy(&node);
+ return res;
+ }
+
+ // Deletion routines.
+ template <typename K = key_type>
+ size_type erase(const key_arg<K> &key) {
+ return this->tree_.erase_multi(key);
+ }
+ using super_type::erase;
+
+ // Node extraction routines.
+ template <typename K = key_type>
+ node_type extract(const key_arg<K> &key) {
+ auto it = this->find(key);
+ return it == this->end() ? node_type() : extract(it);
+ }
+ using super_type::extract;
+
+ // Merge routines.
+ // Moves all elements from `src` into `this`.
+ template <
+ typename T,
+ typename absl::enable_if_t<
+ absl::conjunction<
+ std::is_same<value_type, typename T::value_type>,
+ std::is_same<allocator_type, typename T::allocator_type>,
+ std::is_same<typename params_type::is_map_container,
+ typename T::params_type::is_map_container>>::value,
+ int> = 0>
+ void merge(btree_container<T> &src) { // NOLINT
+ insert(std::make_move_iterator(src.begin()),
+ std::make_move_iterator(src.end()));
+ src.clear();
+ }
+
+ template <
+ typename T,
+ typename absl::enable_if_t<
+ absl::conjunction<
+ std::is_same<value_type, typename T::value_type>,
+ std::is_same<allocator_type, typename T::allocator_type>,
+ std::is_same<typename params_type::is_map_container,
+ typename T::params_type::is_map_container>>::value,
+ int> = 0>
+ void merge(btree_container<T> &&src) {
+ merge(src);
+ }
+};
+
+// A base class for btree_multimap.
+template <typename Tree>
+class btree_multimap_container : public btree_multiset_container<Tree> {
+ using super_type = btree_multiset_container<Tree>;
+ using params_type = typename Tree::params_type;
+
+ public:
+ using mapped_type = typename params_type::mapped_type;
+
+ // Inherit constructors.
+ using super_type::super_type;
+ btree_multimap_container() {}
+};
+
+} // namespace container_internal
+ABSL_NAMESPACE_END
+} // namespace absl
+
+#endif // ABSL_CONTAINER_INTERNAL_BTREE_CONTAINER_H_