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854 lines
31 KiB
854 lines
31 KiB
// 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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// https://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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// ----------------------------------------------------------------------------- |
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// File: btree_map.h |
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// ----------------------------------------------------------------------------- |
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// |
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// This header file defines B-tree maps: sorted associative containers mapping |
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// keys to values. |
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// |
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// * `absl::btree_map<>` |
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// * `absl::btree_multimap<>` |
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// |
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// These B-tree types are similar to the corresponding types in the STL |
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// (`std::map` and `std::multimap`) and generally conform to the STL interfaces |
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// of those types. However, because they are implemented using B-trees, they |
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// are more efficient in most situations. |
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// |
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// Unlike `std::map` and `std::multimap`, which are commonly implemented using |
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// red-black tree nodes, B-tree maps use more generic B-tree nodes able to hold |
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// multiple values per node. Holding multiple values per node often makes |
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// B-tree maps perform better than their `std::map` counterparts, because |
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// multiple entries can be checked within the same cache hit. |
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// |
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// However, these types should not be considered drop-in replacements for |
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// `std::map` and `std::multimap` as there are some API differences, which are |
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// noted in this header file. The most consequential differences with respect to |
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// migrating to b-tree from the STL types are listed in the next paragraph. |
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// Other API differences are minor. |
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// |
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// Importantly, insertions and deletions may invalidate outstanding iterators, |
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// pointers, and references to elements. Such invalidations are typically only |
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// an issue if insertion and deletion operations are interleaved with the use of |
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// more than one iterator, pointer, or reference simultaneously. For this |
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// reason, `insert()` and `erase()` return a valid iterator at the current |
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// position. Another important difference is that key-types must be |
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// copy-constructible. |
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// |
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// Another API difference is that btree iterators can be subtracted, and this |
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// is faster than using std::distance. |
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#ifndef ABSL_CONTAINER_BTREE_MAP_H_ |
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#define ABSL_CONTAINER_BTREE_MAP_H_ |
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#include "absl/container/internal/btree.h" // IWYU pragma: export |
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#include "absl/container/internal/btree_container.h" // IWYU pragma: export |
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namespace absl { |
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ABSL_NAMESPACE_BEGIN |
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namespace container_internal { |
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template <typename Key, typename Data, typename Compare, typename Alloc, |
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int TargetNodeSize, bool IsMulti> |
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struct map_params; |
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} // namespace container_internal |
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// absl::btree_map<> |
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// |
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// An `absl::btree_map<K, V>` is an ordered associative container of |
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// unique keys and associated values designed to be a more efficient replacement |
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// for `std::map` (in most cases). |
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// |
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// Keys are sorted using an (optional) comparison function, which defaults to |
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// `std::less<K>`. |
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// |
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// An `absl::btree_map<K, V>` uses a default allocator of |
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// `std::allocator<std::pair<const K, V>>` to allocate (and deallocate) |
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// nodes, and construct and destruct values within those nodes. You may |
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// instead specify a custom allocator `A` (which in turn requires specifying a |
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// custom comparator `C`) as in `absl::btree_map<K, V, C, A>`. |
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// |
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template <typename Key, typename Value, typename Compare = std::less<Key>, |
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typename Alloc = std::allocator<std::pair<const Key, Value>>> |
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class btree_map |
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: public container_internal::btree_map_container< |
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container_internal::btree<container_internal::map_params< |
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Key, Value, Compare, Alloc, /*TargetNodeSize=*/256, |
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/*IsMulti=*/false>>> { |
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using Base = typename btree_map::btree_map_container; |
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public: |
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// Constructors and Assignment Operators |
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// |
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// A `btree_map` supports the same overload set as `std::map` |
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// for construction and assignment: |
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// |
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// * Default constructor |
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// |
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// absl::btree_map<int, std::string> map1; |
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// |
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// * Initializer List constructor |
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// |
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// absl::btree_map<int, std::string> map2 = |
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// {{1, "huey"}, {2, "dewey"}, {3, "louie"},}; |
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// |
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// * Copy constructor |
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// |
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// absl::btree_map<int, std::string> map3(map2); |
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// |
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// * Copy assignment operator |
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// |
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// absl::btree_map<int, std::string> map4; |
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// map4 = map3; |
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// |
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// * Move constructor |
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// |
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// // Move is guaranteed efficient |
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// absl::btree_map<int, std::string> map5(std::move(map4)); |
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// |
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// * Move assignment operator |
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// |
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// // May be efficient if allocators are compatible |
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// absl::btree_map<int, std::string> map6; |
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// map6 = std::move(map5); |
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// |
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// * Range constructor |
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// |
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// std::vector<std::pair<int, std::string>> v = {{1, "a"}, {2, "b"}}; |
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// absl::btree_map<int, std::string> map7(v.begin(), v.end()); |
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btree_map() {} |
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using Base::Base; |
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// btree_map::begin() |
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// |
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// Returns an iterator to the beginning of the `btree_map`. |
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using Base::begin; |
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// btree_map::cbegin() |
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// |
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// Returns a const iterator to the beginning of the `btree_map`. |
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using Base::cbegin; |
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// btree_map::end() |
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// |
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// Returns an iterator to the end of the `btree_map`. |
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using Base::end; |
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// btree_map::cend() |
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// |
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// Returns a const iterator to the end of the `btree_map`. |
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using Base::cend; |
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// btree_map::empty() |
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// |
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// Returns whether or not the `btree_map` is empty. |
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using Base::empty; |
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// btree_map::max_size() |
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// |
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// Returns the largest theoretical possible number of elements within a |
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// `btree_map` under current memory constraints. This value can be thought |
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// of as the largest value of `std::distance(begin(), end())` for a |
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// `btree_map<Key, T>`. |
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using Base::max_size; |
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// btree_map::size() |
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// |
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// Returns the number of elements currently within the `btree_map`. |
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using Base::size; |
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// btree_map::clear() |
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// |
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// Removes all elements from the `btree_map`. Invalidates any references, |
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// pointers, or iterators referring to contained elements. |
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using Base::clear; |
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// btree_map::erase() |
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// |
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// Erases elements within the `btree_map`. If an erase occurs, any references, |
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// pointers, or iterators are invalidated. |
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// Overloads are listed below. |
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// |
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// iterator erase(iterator position): |
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// iterator erase(const_iterator position): |
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// |
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// Erases the element at `position` of the `btree_map`, returning |
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// the iterator pointing to the element after the one that was erased |
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// (or end() if none exists). |
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// |
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// iterator erase(const_iterator first, const_iterator last): |
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// |
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// Erases the elements in the open interval [`first`, `last`), returning |
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// the iterator pointing to the element after the interval that was erased |
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// (or end() if none exists). |
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// |
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// template <typename K> size_type erase(const K& key): |
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// |
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// Erases the element with the matching key, if it exists, returning the |
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// number of elements erased (0 or 1). |
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using Base::erase; |
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// btree_map::insert() |
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// |
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// Inserts an element of the specified value into the `btree_map`, |
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// returning an iterator pointing to the newly inserted element, provided that |
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// an element with the given key does not already exist. If an insertion |
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// occurs, any references, pointers, or iterators are invalidated. |
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// Overloads are listed below. |
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// |
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// std::pair<iterator,bool> insert(const value_type& value): |
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// |
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// Inserts a value into the `btree_map`. Returns a pair consisting of an |
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// iterator to the inserted element (or to the element that prevented the |
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// insertion) and a bool denoting whether the insertion took place. |
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// |
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// std::pair<iterator,bool> insert(value_type&& value): |
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// |
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// Inserts a moveable value into the `btree_map`. Returns a pair |
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// consisting of an iterator to the inserted element (or to the element that |
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// prevented the insertion) and a bool denoting whether the insertion took |
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// place. |
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// |
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// iterator insert(const_iterator hint, const value_type& value): |
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// iterator insert(const_iterator hint, value_type&& value): |
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// |
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// Inserts a value, using the position of `hint` as a non-binding suggestion |
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// for where to begin the insertion search. Returns an iterator to the |
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// inserted element, or to the existing element that prevented the |
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// insertion. |
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// |
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// void insert(InputIterator first, InputIterator last): |
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// |
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// Inserts a range of values [`first`, `last`). |
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// |
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// void insert(std::initializer_list<init_type> ilist): |
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// |
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// Inserts the elements within the initializer list `ilist`. |
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using Base::insert; |
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// btree_map::insert_or_assign() |
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// |
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// Inserts an element of the specified value into the `btree_map` provided |
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// that a value with the given key does not already exist, or replaces the |
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// corresponding mapped type with the forwarded `obj` argument if a key for |
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// that value already exists, returning an iterator pointing to the newly |
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// inserted element. Overloads are listed below. |
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// |
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// pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj): |
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// pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj): |
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// |
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// Inserts/Assigns (or moves) the element of the specified key into the |
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// `btree_map`. If the returned bool is true, insertion took place, and if |
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// it's false, assignment took place. |
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// |
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// iterator insert_or_assign(const_iterator hint, |
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// const key_type& k, M&& obj): |
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// iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj): |
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// |
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// Inserts/Assigns (or moves) the element of the specified key into the |
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// `btree_map` using the position of `hint` as a non-binding suggestion |
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// for where to begin the insertion search. |
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using Base::insert_or_assign; |
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// btree_map::emplace() |
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// |
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// Inserts an element of the specified value by constructing it in-place |
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// within the `btree_map`, provided that no element with the given key |
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// already exists. |
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// |
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// The element may be constructed even if there already is an element with the |
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// key in the container, in which case the newly constructed element will be |
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// destroyed immediately. Prefer `try_emplace()` unless your key is not |
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// copyable or moveable. |
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// |
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// If an insertion occurs, any references, pointers, or iterators are |
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// invalidated. |
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using Base::emplace; |
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// btree_map::emplace_hint() |
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// |
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// Inserts an element of the specified value by constructing it in-place |
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// within the `btree_map`, using the position of `hint` as a non-binding |
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// suggestion for where to begin the insertion search, and only inserts |
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// provided that no element with the given key already exists. |
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// |
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// The element may be constructed even if there already is an element with the |
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// key in the container, in which case the newly constructed element will be |
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// destroyed immediately. Prefer `try_emplace()` unless your key is not |
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// copyable or moveable. |
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// |
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// If an insertion occurs, any references, pointers, or iterators are |
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// invalidated. |
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using Base::emplace_hint; |
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// btree_map::try_emplace() |
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// |
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// Inserts an element of the specified value by constructing it in-place |
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// within the `btree_map`, provided that no element with the given key |
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// already exists. Unlike `emplace()`, if an element with the given key |
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// already exists, we guarantee that no element is constructed. |
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// |
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// If an insertion occurs, any references, pointers, or iterators are |
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// invalidated. |
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// |
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// Overloads are listed below. |
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// |
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// std::pair<iterator, bool> try_emplace(const key_type& k, Args&&... args): |
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// std::pair<iterator, bool> try_emplace(key_type&& k, Args&&... args): |
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// |
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// Inserts (via copy or move) the element of the specified key into the |
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// `btree_map`. |
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// |
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// iterator try_emplace(const_iterator hint, |
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// const key_type& k, Args&&... args): |
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// iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args): |
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// |
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// Inserts (via copy or move) the element of the specified key into the |
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// `btree_map` using the position of `hint` as a non-binding suggestion |
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// for where to begin the insertion search. |
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using Base::try_emplace; |
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// btree_map::extract() |
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// |
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// Extracts the indicated element, erasing it in the process, and returns it |
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// as a C++17-compatible node handle. Overloads are listed below. |
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// |
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// node_type extract(const_iterator position): |
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// |
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// Extracts the element at the indicated position and returns a node handle |
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// owning that extracted data. |
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// |
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// template <typename K> node_type extract(const K& k): |
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// |
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// Extracts the element with the key matching the passed key value and |
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// returns a node handle owning that extracted data. If the `btree_map` |
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// does not contain an element with a matching key, this function returns an |
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// empty node handle. |
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// |
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// NOTE: when compiled in an earlier version of C++ than C++17, |
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// `node_type::key()` returns a const reference to the key instead of a |
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// mutable reference. We cannot safely return a mutable reference without |
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// std::launder (which is not available before C++17). |
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// |
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// NOTE: In this context, `node_type` refers to the C++17 concept of a |
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// move-only type that owns and provides access to the elements in associative |
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// containers (https://en.cppreference.com/w/cpp/container/node_handle). |
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// It does NOT refer to the data layout of the underlying btree. |
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using Base::extract; |
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// btree_map::merge() |
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// |
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// Extracts elements from a given `source` btree_map into this |
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// `btree_map`. If the destination `btree_map` already contains an |
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// element with an equivalent key, that element is not extracted. |
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using Base::merge; |
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// btree_map::swap(btree_map& other) |
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// |
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// Exchanges the contents of this `btree_map` with those of the `other` |
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// btree_map, avoiding invocation of any move, copy, or swap operations on |
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// individual elements. |
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// |
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// All iterators and references on the `btree_map` remain valid, excepting |
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// for the past-the-end iterator, which is invalidated. |
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using Base::swap; |
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// btree_map::at() |
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// |
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// Returns a reference to the mapped value of the element with key equivalent |
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// to the passed key. |
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using Base::at; |
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// btree_map::contains() |
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// |
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// template <typename K> bool contains(const K& key) const: |
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// |
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// Determines whether an element comparing equal to the given `key` exists |
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// within the `btree_map`, returning `true` if so or `false` otherwise. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::contains; |
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// btree_map::count() |
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// |
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// template <typename K> size_type count(const K& key) const: |
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// |
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// Returns the number of elements comparing equal to the given `key` within |
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// the `btree_map`. Note that this function will return either `1` or `0` |
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// since duplicate elements are not allowed within a `btree_map`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::count; |
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// btree_map::equal_range() |
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// |
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// Returns a half-open range [first, last), defined by a `std::pair` of two |
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// iterators, containing all elements with the passed key in the `btree_map`. |
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using Base::equal_range; |
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// btree_map::find() |
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// |
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// template <typename K> iterator find(const K& key): |
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// template <typename K> const_iterator find(const K& key) const: |
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// |
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// Finds an element with the passed `key` within the `btree_map`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::find; |
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// btree_map::lower_bound() |
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// |
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// template <typename K> iterator lower_bound(const K& key): |
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// template <typename K> const_iterator lower_bound(const K& key) const: |
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// |
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// Finds the first element with a key that is not less than `key` within the |
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// `btree_map`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::lower_bound; |
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// btree_map::upper_bound() |
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// |
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// template <typename K> iterator upper_bound(const K& key): |
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// template <typename K> const_iterator upper_bound(const K& key) const: |
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// |
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// Finds the first element with a key that is greater than `key` within the |
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// `btree_map`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::upper_bound; |
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// btree_map::operator[]() |
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// |
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// Returns a reference to the value mapped to the passed key within the |
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// `btree_map`, performing an `insert()` if the key does not already |
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// exist. |
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// |
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// If an insertion occurs, any references, pointers, or iterators are |
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// invalidated. Otherwise iterators are not affected and references are not |
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// invalidated. Overloads are listed below. |
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// |
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// T& operator[](key_type&& key): |
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// T& operator[](const key_type& key): |
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// |
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// Inserts a value_type object constructed in-place if the element with the |
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// given key does not exist. |
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using Base::operator[]; |
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// btree_map::get_allocator() |
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// |
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// Returns the allocator function associated with this `btree_map`. |
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using Base::get_allocator; |
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// btree_map::key_comp(); |
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// |
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// Returns the key comparator associated with this `btree_map`. |
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using Base::key_comp; |
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// btree_map::value_comp(); |
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// |
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// Returns the value comparator associated with this `btree_map`. |
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using Base::value_comp; |
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}; |
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// absl::swap(absl::btree_map<>, absl::btree_map<>) |
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// |
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// Swaps the contents of two `absl::btree_map` containers. |
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template <typename K, typename V, typename C, typename A> |
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void swap(btree_map<K, V, C, A> &x, btree_map<K, V, C, A> &y) { |
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return x.swap(y); |
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} |
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// absl::erase_if(absl::btree_map<>, Pred) |
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// |
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// Erases all elements that satisfy the predicate pred from the container. |
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// Returns the number of erased elements. |
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template <typename K, typename V, typename C, typename A, typename Pred> |
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typename btree_map<K, V, C, A>::size_type erase_if( |
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btree_map<K, V, C, A> &map, Pred pred) { |
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return container_internal::btree_access::erase_if(map, std::move(pred)); |
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} |
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// absl::btree_multimap |
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// |
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// An `absl::btree_multimap<K, V>` is an ordered associative container of |
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// keys and associated values designed to be a more efficient replacement for |
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// `std::multimap` (in most cases). Unlike `absl::btree_map`, a B-tree multimap |
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// allows multiple elements with equivalent keys. |
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// |
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// Keys are sorted using an (optional) comparison function, which defaults to |
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// `std::less<K>`. |
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// |
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// An `absl::btree_multimap<K, V>` uses a default allocator of |
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// `std::allocator<std::pair<const K, V>>` to allocate (and deallocate) |
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// nodes, and construct and destruct values within those nodes. You may |
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// instead specify a custom allocator `A` (which in turn requires specifying a |
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// custom comparator `C`) as in `absl::btree_multimap<K, V, C, A>`. |
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// |
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template <typename Key, typename Value, typename Compare = std::less<Key>, |
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typename Alloc = std::allocator<std::pair<const Key, Value>>> |
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class btree_multimap |
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: public container_internal::btree_multimap_container< |
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container_internal::btree<container_internal::map_params< |
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Key, Value, Compare, Alloc, /*TargetNodeSize=*/256, |
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/*IsMulti=*/true>>> { |
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using Base = typename btree_multimap::btree_multimap_container; |
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|
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public: |
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// Constructors and Assignment Operators |
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// |
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// A `btree_multimap` supports the same overload set as `std::multimap` |
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// for construction and assignment: |
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// |
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// * Default constructor |
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// |
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// absl::btree_multimap<int, std::string> map1; |
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// |
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// * Initializer List constructor |
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// |
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// absl::btree_multimap<int, std::string> map2 = |
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// {{1, "huey"}, {2, "dewey"}, {3, "louie"},}; |
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// |
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// * Copy constructor |
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// |
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// absl::btree_multimap<int, std::string> map3(map2); |
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// |
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// * Copy assignment operator |
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// |
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// absl::btree_multimap<int, std::string> map4; |
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// map4 = map3; |
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// |
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// * Move constructor |
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// |
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// // Move is guaranteed efficient |
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// absl::btree_multimap<int, std::string> map5(std::move(map4)); |
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// |
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// * Move assignment operator |
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// |
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// // May be efficient if allocators are compatible |
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// absl::btree_multimap<int, std::string> map6; |
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// map6 = std::move(map5); |
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// |
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// * Range constructor |
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// |
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// std::vector<std::pair<int, std::string>> v = {{1, "a"}, {2, "b"}}; |
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// absl::btree_multimap<int, std::string> map7(v.begin(), v.end()); |
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btree_multimap() {} |
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using Base::Base; |
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|
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// btree_multimap::begin() |
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// |
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// Returns an iterator to the beginning of the `btree_multimap`. |
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using Base::begin; |
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|
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// btree_multimap::cbegin() |
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// |
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// Returns a const iterator to the beginning of the `btree_multimap`. |
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using Base::cbegin; |
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|
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// btree_multimap::end() |
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// |
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// Returns an iterator to the end of the `btree_multimap`. |
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using Base::end; |
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|
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// btree_multimap::cend() |
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// |
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// Returns a const iterator to the end of the `btree_multimap`. |
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using Base::cend; |
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|
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// btree_multimap::empty() |
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// |
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// Returns whether or not the `btree_multimap` is empty. |
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using Base::empty; |
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|
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// btree_multimap::max_size() |
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// |
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// Returns the largest theoretical possible number of elements within a |
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// `btree_multimap` under current memory constraints. This value can be |
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// thought of as the largest value of `std::distance(begin(), end())` for a |
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// `btree_multimap<Key, T>`. |
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using Base::max_size; |
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|
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// btree_multimap::size() |
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// |
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// Returns the number of elements currently within the `btree_multimap`. |
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using Base::size; |
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// btree_multimap::clear() |
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// |
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// Removes all elements from the `btree_multimap`. Invalidates any references, |
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// pointers, or iterators referring to contained elements. |
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using Base::clear; |
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// btree_multimap::erase() |
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// |
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// Erases elements within the `btree_multimap`. If an erase occurs, any |
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// references, pointers, or iterators are invalidated. |
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// Overloads are listed below. |
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// |
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// iterator erase(iterator position): |
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// iterator erase(const_iterator position): |
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// |
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// Erases the element at `position` of the `btree_multimap`, returning |
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// the iterator pointing to the element after the one that was erased |
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// (or end() if none exists). |
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// |
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// iterator erase(const_iterator first, const_iterator last): |
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// |
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// Erases the elements in the open interval [`first`, `last`), returning |
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// the iterator pointing to the element after the interval that was erased |
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// (or end() if none exists). |
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// |
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// template <typename K> size_type erase(const K& key): |
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// |
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// Erases the elements matching the key, if any exist, returning the |
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// number of elements erased. |
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using Base::erase; |
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// btree_multimap::insert() |
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// |
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// Inserts an element of the specified value into the `btree_multimap`, |
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// returning an iterator pointing to the newly inserted element. |
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// Any references, pointers, or iterators are invalidated. Overloads are |
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// listed below. |
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// |
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// iterator insert(const value_type& value): |
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// |
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// Inserts a value into the `btree_multimap`, returning an iterator to the |
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// inserted element. |
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// |
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// iterator insert(value_type&& value): |
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// |
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// Inserts a moveable value into the `btree_multimap`, returning an iterator |
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// to the inserted element. |
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// |
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// iterator insert(const_iterator hint, const value_type& value): |
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// iterator insert(const_iterator hint, value_type&& value): |
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// |
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// Inserts a value, using the position of `hint` as a non-binding suggestion |
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// for where to begin the insertion search. Returns an iterator to the |
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// inserted element. |
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// |
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// void insert(InputIterator first, InputIterator last): |
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// |
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// Inserts a range of values [`first`, `last`). |
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// |
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// void insert(std::initializer_list<init_type> ilist): |
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// |
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// Inserts the elements within the initializer list `ilist`. |
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using Base::insert; |
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// btree_multimap::emplace() |
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// |
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// Inserts an element of the specified value by constructing it in-place |
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// within the `btree_multimap`. Any references, pointers, or iterators are |
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// invalidated. |
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using Base::emplace; |
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// btree_multimap::emplace_hint() |
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// |
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// Inserts an element of the specified value by constructing it in-place |
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// within the `btree_multimap`, using the position of `hint` as a non-binding |
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// suggestion for where to begin the insertion search. |
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// |
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// Any references, pointers, or iterators are invalidated. |
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using Base::emplace_hint; |
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// btree_multimap::extract() |
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// |
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// Extracts the indicated element, erasing it in the process, and returns it |
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// as a C++17-compatible node handle. Overloads are listed below. |
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// |
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// node_type extract(const_iterator position): |
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// |
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// Extracts the element at the indicated position and returns a node handle |
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// owning that extracted data. |
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// |
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// template <typename K> node_type extract(const K& k): |
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// |
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// Extracts the element with the key matching the passed key value and |
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// returns a node handle owning that extracted data. If the `btree_multimap` |
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// does not contain an element with a matching key, this function returns an |
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// empty node handle. |
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// |
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// NOTE: when compiled in an earlier version of C++ than C++17, |
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// `node_type::key()` returns a const reference to the key instead of a |
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// mutable reference. We cannot safely return a mutable reference without |
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// std::launder (which is not available before C++17). |
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// |
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// NOTE: In this context, `node_type` refers to the C++17 concept of a |
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// move-only type that owns and provides access to the elements in associative |
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// containers (https://en.cppreference.com/w/cpp/container/node_handle). |
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// It does NOT refer to the data layout of the underlying btree. |
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using Base::extract; |
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// btree_multimap::merge() |
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// |
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// Extracts all elements from a given `source` btree_multimap into this |
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// `btree_multimap`. |
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using Base::merge; |
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// btree_multimap::swap(btree_multimap& other) |
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// |
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// Exchanges the contents of this `btree_multimap` with those of the `other` |
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// btree_multimap, avoiding invocation of any move, copy, or swap operations |
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// on individual elements. |
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// |
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// All iterators and references on the `btree_multimap` remain valid, |
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// excepting for the past-the-end iterator, which is invalidated. |
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using Base::swap; |
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// btree_multimap::contains() |
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// |
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// template <typename K> bool contains(const K& key) const: |
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// |
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// Determines whether an element comparing equal to the given `key` exists |
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// within the `btree_multimap`, returning `true` if so or `false` otherwise. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::contains; |
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// btree_multimap::count() |
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// |
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// template <typename K> size_type count(const K& key) const: |
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// |
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// Returns the number of elements comparing equal to the given `key` within |
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// the `btree_multimap`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::count; |
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// btree_multimap::equal_range() |
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// |
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// Returns a half-open range [first, last), defined by a `std::pair` of two |
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// iterators, containing all elements with the passed key in the |
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// `btree_multimap`. |
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using Base::equal_range; |
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// btree_multimap::find() |
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// |
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// template <typename K> iterator find(const K& key): |
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// template <typename K> const_iterator find(const K& key) const: |
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// |
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// Finds an element with the passed `key` within the `btree_multimap`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::find; |
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// btree_multimap::lower_bound() |
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// |
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// template <typename K> iterator lower_bound(const K& key): |
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// template <typename K> const_iterator lower_bound(const K& key) const: |
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// |
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// Finds the first element with a key that is not less than `key` within the |
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// `btree_multimap`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::lower_bound; |
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// btree_multimap::upper_bound() |
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// |
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// template <typename K> iterator upper_bound(const K& key): |
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// template <typename K> const_iterator upper_bound(const K& key) const: |
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// |
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// Finds the first element with a key that is greater than `key` within the |
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// `btree_multimap`. |
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// |
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// Supports heterogeneous lookup, provided that the map has a compatible |
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// heterogeneous comparator. |
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using Base::upper_bound; |
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// btree_multimap::get_allocator() |
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// |
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// Returns the allocator function associated with this `btree_multimap`. |
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using Base::get_allocator; |
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// btree_multimap::key_comp(); |
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// |
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// Returns the key comparator associated with this `btree_multimap`. |
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using Base::key_comp; |
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// btree_multimap::value_comp(); |
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// |
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// Returns the value comparator associated with this `btree_multimap`. |
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using Base::value_comp; |
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}; |
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// absl::swap(absl::btree_multimap<>, absl::btree_multimap<>) |
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// |
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// Swaps the contents of two `absl::btree_multimap` containers. |
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template <typename K, typename V, typename C, typename A> |
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void swap(btree_multimap<K, V, C, A> &x, btree_multimap<K, V, C, A> &y) { |
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return x.swap(y); |
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} |
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// absl::erase_if(absl::btree_multimap<>, Pred) |
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// |
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// Erases all elements that satisfy the predicate pred from the container. |
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// Returns the number of erased elements. |
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template <typename K, typename V, typename C, typename A, typename Pred> |
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typename btree_multimap<K, V, C, A>::size_type erase_if( |
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btree_multimap<K, V, C, A> &map, Pred pred) { |
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return container_internal::btree_access::erase_if(map, std::move(pred)); |
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} |
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namespace container_internal { |
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// A parameters structure for holding the type parameters for a btree_map. |
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// Compare and Alloc should be nothrow copy-constructible. |
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template <typename Key, typename Data, typename Compare, typename Alloc, |
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int TargetNodeSize, bool IsMulti> |
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struct map_params : common_params<Key, Compare, Alloc, TargetNodeSize, IsMulti, |
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/*IsMap=*/true, map_slot_policy<Key, Data>> { |
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using super_type = typename map_params::common_params; |
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using mapped_type = Data; |
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// This type allows us to move keys when it is safe to do so. It is safe |
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// for maps in which value_type and mutable_value_type are layout compatible. |
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using slot_policy = typename super_type::slot_policy; |
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using slot_type = typename super_type::slot_type; |
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using value_type = typename super_type::value_type; |
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using init_type = typename super_type::init_type; |
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template <typename V> |
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static auto key(const V &value) -> decltype(value.first) { |
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return value.first; |
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} |
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static const Key &key(const slot_type *s) { return slot_policy::key(s); } |
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static const Key &key(slot_type *s) { return slot_policy::key(s); } |
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// For use in node handle. |
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static auto mutable_key(slot_type *s) |
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-> decltype(slot_policy::mutable_key(s)) { |
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return slot_policy::mutable_key(s); |
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} |
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static mapped_type &value(value_type *value) { return value->second; } |
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}; |
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} // namespace container_internal |
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ABSL_NAMESPACE_END |
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} // namespace absl |
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#endif // ABSL_CONTAINER_BTREE_MAP_H_
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