769 lines
27 KiB
C
769 lines
27 KiB
C
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// 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.
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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.
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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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// 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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/*Multi=*/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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//
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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.
|
||
|
|
//
|
||
|
|
// All iterators and references on the `btree_map` remain valid, excepting
|
||
|
|
// for the past-the-end iterator, which is invalidated.
|
||
|
|
using Base::swap;
|
||
|
|
|
||
|
|
// btree_map::at()
|
||
|
|
//
|
||
|
|
// Returns a reference to the mapped value of the element with key equivalent
|
||
|
|
// to the passed key.
|
||
|
|
using Base::at;
|
||
|
|
|
||
|
|
// btree_map::contains()
|
||
|
|
//
|
||
|
|
// template <typename K> bool contains(const K& key) const:
|
||
|
|
//
|
||
|
|
// Determines whether an element comparing equal to the given `key` exists
|
||
|
|
// within the `btree_map`, returning `true` if so or `false` otherwise.
|
||
|
|
//
|
||
|
|
// Supports heterogeneous lookup, provided that the map is provided a
|
||
|
|
// compatible heterogeneous comparator.
|
||
|
|
using Base::contains;
|
||
|
|
|
||
|
|
// btree_map::count()
|
||
|
|
//
|
||
|
|
// template <typename K> size_type count(const K& key) const:
|
||
|
|
//
|
||
|
|
// Returns the number of elements comparing equal to the given `key` within
|
||
|
|
// the `btree_map`. Note that this function will return either `1` or `0`
|
||
|
|
// since duplicate elements are not allowed within a `btree_map`.
|
||
|
|
//
|
||
|
|
// Supports heterogeneous lookup, provided that the map is provided a
|
||
|
|
// compatible heterogeneous comparator.
|
||
|
|
using Base::count;
|
||
|
|
|
||
|
|
// btree_map::equal_range()
|
||
|
|
//
|
||
|
|
// Returns a half-open range [first, last), defined by a `std::pair` of two
|
||
|
|
// iterators, containing all elements with the passed key in the `btree_map`.
|
||
|
|
using Base::equal_range;
|
||
|
|
|
||
|
|
// btree_map::find()
|
||
|
|
//
|
||
|
|
// template <typename K> iterator find(const K& key):
|
||
|
|
// template <typename K> const_iterator find(const K& key) const:
|
||
|
|
//
|
||
|
|
// Finds an element with the passed `key` within the `btree_map`.
|
||
|
|
//
|
||
|
|
// Supports heterogeneous lookup, provided that the map is provided a
|
||
|
|
// compatible heterogeneous comparator.
|
||
|
|
using Base::find;
|
||
|
|
|
||
|
|
// btree_map::operator[]()
|
||
|
|
//
|
||
|
|
// Returns a reference to the value mapped to the passed key within the
|
||
|
|
// `btree_map`, performing an `insert()` if the key does not already
|
||
|
|
// exist.
|
||
|
|
//
|
||
|
|
// If an insertion occurs, any references, pointers, or iterators are
|
||
|
|
// invalidated. Otherwise iterators are not affected and references are not
|
||
|
|
// invalidated. Overloads are listed below.
|
||
|
|
//
|
||
|
|
// T& operator[](key_type&& key):
|
||
|
|
// T& operator[](const key_type& key):
|
||
|
|
//
|
||
|
|
// Inserts a value_type object constructed in-place if the element with the
|
||
|
|
// given key does not exist.
|
||
|
|
using Base::operator[];
|
||
|
|
|
||
|
|
// btree_map::get_allocator()
|
||
|
|
//
|
||
|
|
// Returns the allocator function associated with this `btree_map`.
|
||
|
|
using Base::get_allocator;
|
||
|
|
|
||
|
|
// btree_map::key_comp();
|
||
|
|
//
|
||
|
|
// Returns the key comparator associated with this `btree_map`.
|
||
|
|
using Base::key_comp;
|
||
|
|
|
||
|
|
// btree_map::value_comp();
|
||
|
|
//
|
||
|
|
// Returns the value comparator associated with this `btree_map`.
|
||
|
|
using Base::value_comp;
|
||
|
|
};
|
||
|
|
|
||
|
|
// absl::swap(absl::btree_map<>, absl::btree_map<>)
|
||
|
|
//
|
||
|
|
// Swaps the contents of two `absl::btree_map` containers.
|
||
|
|
template <typename K, typename V, typename C, typename A>
|
||
|
|
void swap(btree_map<K, V, C, A> &x, btree_map<K, V, C, A> &y) {
|
||
|
|
return x.swap(y);
|
||
|
|
}
|
||
|
|
|
||
|
|
// absl::erase_if(absl::btree_map<>, Pred)
|
||
|
|
//
|
||
|
|
// Erases all elements that satisfy the predicate pred from the container.
|
||
|
|
template <typename K, typename V, typename C, typename A, typename Pred>
|
||
|
|
void erase_if(btree_map<K, V, C, A> &map, Pred pred) {
|
||
|
|
for (auto it = map.begin(); it != map.end();) {
|
||
|
|
if (pred(*it)) {
|
||
|
|
it = map.erase(it);
|
||
|
|
} else {
|
||
|
|
++it;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// absl::btree_multimap
|
||
|
|
//
|
||
|
|
// An `absl::btree_multimap<K, V>` is an ordered associative container of
|
||
|
|
// keys and associated values designed to be a more efficient replacement for
|
||
|
|
// `std::multimap` (in most cases). Unlike `absl::btree_map`, a B-tree multimap
|
||
|
|
// allows multiple elements with equivalent keys.
|
||
|
|
//
|
||
|
|
// Keys are sorted using an (optional) comparison function, which defaults to
|
||
|
|
// `std::less<K>`.
|
||
|
|
//
|
||
|
|
// An `absl::btree_multimap<K, V>` uses a default allocator of
|
||
|
|
// `std::allocator<std::pair<const K, V>>` to allocate (and deallocate)
|
||
|
|
// nodes, and construct and destruct values within those nodes. You may
|
||
|
|
// instead specify a custom allocator `A` (which in turn requires specifying a
|
||
|
|
// custom comparator `C`) as in `absl::btree_multimap<K, V, C, A>`.
|
||
|
|
//
|
||
|
|
template <typename Key, typename Value, typename Compare = std::less<Key>,
|
||
|
|
typename Alloc = std::allocator<std::pair<const Key, Value>>>
|
||
|
|
class btree_multimap
|
||
|
|
: public container_internal::btree_multimap_container<
|
||
|
|
container_internal::btree<container_internal::map_params<
|
||
|
|
Key, Value, Compare, Alloc, /*TargetNodeSize=*/256,
|
||
|
|
/*Multi=*/true>>> {
|
||
|
|
using Base = typename btree_multimap::btree_multimap_container;
|
||
|
|
|
||
|
|
public:
|
||
|
|
// Constructors and Assignment Operators
|
||
|
|
//
|
||
|
|
// A `btree_multimap` supports the same overload set as `std::multimap`
|
||
|
|
// for construction and assignment:
|
||
|
|
//
|
||
|
|
// * Default constructor
|
||
|
|
//
|
||
|
|
// absl::btree_multimap<int, std::string> map1;
|
||
|
|
//
|
||
|
|
// * Initializer List constructor
|
||
|
|
//
|
||
|
|
// absl::btree_multimap<int, std::string> map2 =
|
||
|
|
// {{1, "huey"}, {2, "dewey"}, {3, "louie"},};
|
||
|
|
//
|
||
|
|
// * Copy constructor
|
||
|
|
//
|
||
|
|
// absl::btree_multimap<int, std::string> map3(map2);
|
||
|
|
//
|
||
|
|
// * Copy assignment operator
|
||
|
|
//
|
||
|
|
// absl::btree_multimap<int, std::string> map4;
|
||
|
|
// map4 = map3;
|
||
|
|
//
|
||
|
|
// * Move constructor
|
||
|
|
//
|
||
|
|
// // Move is guaranteed efficient
|
||
|
|
// absl::btree_multimap<int, std::string> map5(std::move(map4));
|
||
|
|
//
|
||
|
|
// * Move assignment operator
|
||
|
|
//
|
||
|
|
// // May be efficient if allocators are compatible
|
||
|
|
// absl::btree_multimap<int, std::string> map6;
|
||
|
|
// map6 = std::move(map5);
|
||
|
|
//
|
||
|
|
// * Range constructor
|
||
|
|
//
|
||
|
|
// std::vector<std::pair<int, std::string>> v = {{1, "a"}, {2, "b"}};
|
||
|
|
// absl::btree_multimap<int, std::string> map7(v.begin(), v.end());
|
||
|
|
btree_multimap() {}
|
||
|
|
using Base::Base;
|
||
|
|
|
||
|
|
// btree_multimap::begin()
|
||
|
|
//
|
||
|
|
// Returns an iterator to the beginning of the `btree_multimap`.
|
||
|
|
using Base::begin;
|
||
|
|
|
||
|
|
// btree_multimap::cbegin()
|
||
|
|
//
|
||
|
|
// Returns a const iterator to the beginning of the `btree_multimap`.
|
||
|
|
using Base::cbegin;
|
||
|
|
|
||
|
|
// btree_multimap::end()
|
||
|
|
//
|
||
|
|
// Returns an iterator to the end of the `btree_multimap`.
|
||
|
|
using Base::end;
|
||
|
|
|
||
|
|
// btree_multimap::cend()
|
||
|
|
//
|
||
|
|
// Returns a const iterator to the end of the `btree_multimap`.
|
||
|
|
using Base::cend;
|
||
|
|
|
||
|
|
// btree_multimap::empty()
|
||
|
|
//
|
||
|
|
// Returns whether or not the `btree_multimap` is empty.
|
||
|
|
using Base::empty;
|
||
|
|
|
||
|
|
// btree_multimap::max_size()
|
||
|
|
//
|
||
|
|
// Returns the largest theoretical possible number of elements within a
|
||
|
|
// `btree_multimap` under current memory constraints. This value can be
|
||
|
|
// thought of as the largest value of `std::distance(begin(), end())` for a
|
||
|
|
// `btree_multimap<Key, T>`.
|
||
|
|
using Base::max_size;
|
||
|
|
|
||
|
|
// btree_multimap::size()
|
||
|
|
//
|
||
|
|
// Returns the number of elements currently within the `btree_multimap`.
|
||
|
|
using Base::size;
|
||
|
|
|
||
|
|
// btree_multimap::clear()
|
||
|
|
//
|
||
|
|
// Removes all elements from the `btree_multimap`. Invalidates any references,
|
||
|
|
// pointers, or iterators referring to contained elements.
|
||
|
|
using Base::clear;
|
||
|
|
|
||
|
|
// btree_multimap::erase()
|
||
|
|
//
|
||
|
|
// Erases elements within the `btree_multimap`. If an erase occurs, any
|
||
|
|
// references, pointers, or iterators are invalidated.
|
||
|
|
// Overloads are listed below.
|
||
|
|
//
|
||
|
|
// iterator erase(iterator position):
|
||
|
|
// iterator erase(const_iterator position):
|
||
|
|
//
|
||
|
|
// Erases the element at `position` of the `btree_multimap`, returning
|
||
|
|
// the iterator pointing to the element after the one that was erased
|
||
|
|
// (or end() if none exists).
|
||
|
|
//
|
||
|
|
// iterator erase(const_iterator first, const_iterator last):
|
||
|
|
//
|
||
|
|
// Erases the elements in the open interval [`first`, `last`), returning
|
||
|
|
// the iterator pointing to the element after the interval that was erased
|
||
|
|
// (or end() if none exists).
|
||
|
|
//
|
||
|
|
// template <typename K> size_type erase(const K& key):
|
||
|
|
//
|
||
|
|
// Erases the elements matching the key, if any exist, returning the
|
||
|
|
// number of elements erased.
|
||
|
|
using Base::erase;
|
||
|
|
|
||
|
|
// btree_multimap::insert()
|
||
|
|
//
|
||
|
|
// Inserts an element of the specified value into the `btree_multimap`,
|
||
|
|
// returning an iterator pointing to the newly inserted element.
|
||
|
|
// Any references, pointers, or iterators are invalidated. Overloads are
|
||
|
|
// listed below.
|
||
|
|
//
|
||
|
|
// iterator insert(const value_type& value):
|
||
|
|
//
|
||
|
|
// Inserts a value into the `btree_multimap`, returning an iterator to the
|
||
|
|
// inserted element.
|
||
|
|
//
|
||
|
|
// iterator insert(value_type&& value):
|
||
|
|
//
|
||
|
|
// Inserts a moveable value into the `btree_multimap`, returning an iterator
|
||
|
|
// to the inserted element.
|
||
|
|
//
|
||
|
|
// iterator insert(const_iterator hint, const value_type& value):
|
||
|
|
// iterator insert(const_iterator hint, value_type&& value):
|
||
|
|
//
|
||
|
|
// Inserts a value, using the position of `hint` as a non-binding suggestion
|
||
|
|
// for where to begin the insertion search. Returns an iterator to the
|
||
|
|
// inserted element.
|
||
|
|
//
|
||
|
|
// void insert(InputIterator first, InputIterator last):
|
||
|
|
//
|
||
|
|
// Inserts a range of values [`first`, `last`).
|
||
|
|
//
|
||
|
|
// void insert(std::initializer_list<init_type> ilist):
|
||
|
|
//
|
||
|
|
// Inserts the elements within the initializer list `ilist`.
|
||
|
|
using Base::insert;
|
||
|
|
|
||
|
|
// btree_multimap::emplace()
|
||
|
|
//
|
||
|
|
// Inserts an element of the specified value by constructing it in-place
|
||
|
|
// within the `btree_multimap`. Any references, pointers, or iterators are
|
||
|
|
// invalidated.
|
||
|
|
using Base::emplace;
|
||
|
|
|
||
|
|
// btree_multimap::emplace_hint()
|
||
|
|
//
|
||
|
|
// Inserts an element of the specified value by constructing it in-place
|
||
|
|
// within the `btree_multimap`, using the position of `hint` as a non-binding
|
||
|
|
// suggestion for where to begin the insertion search.
|
||
|
|
//
|
||
|
|
// Any references, pointers, or iterators are invalidated.
|
||
|
|
using Base::emplace_hint;
|
||
|
|
|
||
|
|
// btree_multimap::extract()
|
||
|
|
//
|
||
|
|
// Extracts the indicated element, erasing it in the process, and returns it
|
||
|
|
// as a C++17-compatible node handle. Overloads are listed below.
|
||
|
|
//
|
||
|
|
// node_type extract(const_iterator position):
|
||
|
|
//
|
||
|
|
// Extracts the element at the indicated position and returns a node handle
|
||
|
|
// owning that extracted data.
|
||
|
|
//
|
||
|
|
// template <typename K> node_type extract(const K& k):
|
||
|
|
//
|
||
|
|
// Extracts the element with the key matching the passed key value and
|
||
|
|
// returns a node handle owning that extracted data. If the `btree_multimap`
|
||
|
|
// does not contain an element with a matching key, this function returns an
|
||
|
|
// empty node handle.
|
||
|
|
//
|
||
|
|
// NOTE: when compiled in an earlier version of C++ than C++17,
|
||
|
|
// `node_type::key()` returns a const reference to the key instead of a
|
||
|
|
// mutable reference. We cannot safely return a mutable reference without
|
||
|
|
// std::launder (which is not available before C++17).
|
||
|
|
//
|
||
|
|
// NOTE: In this context, `node_type` refers to the C++17 concept of a
|
||
|
|
// move-only type that owns and provides access to the elements in associative
|
||
|
|
// containers (https://en.cppreference.com/w/cpp/container/node_handle).
|
||
|
|
// It does NOT refer to the data layout of the underlying btree.
|
||
|
|
using Base::extract;
|
||
|
|
|
||
|
|
// btree_multimap::merge()
|
||
|
|
//
|
||
|
|
// Extracts elements from a given `source` btree_multimap into this
|
||
|
|
// `btree_multimap`. If the destination `btree_multimap` already contains an
|
||
|
|
// element with an equivalent key, that element is not extracted.
|
||
|
|
using Base::merge;
|
||
|
|
|
||
|
|
// btree_multimap::swap(btree_multimap& other)
|
||
|
|
//
|
||
|
|
// Exchanges the contents of this `btree_multimap` with those of the `other`
|
||
|
|
// btree_multimap, avoiding invocation of any move, copy, or swap operations
|
||
|
|
// on individual elements.
|
||
|
|
//
|
||
|
|
// All iterators and references on the `btree_multimap` remain valid,
|
||
|
|
// excepting for the past-the-end iterator, which is invalidated.
|
||
|
|
using Base::swap;
|
||
|
|
|
||
|
|
// btree_multimap::contains()
|
||
|
|
//
|
||
|
|
// template <typename K> bool contains(const K& key) const:
|
||
|
|
//
|
||
|
|
// Determines whether an element comparing equal to the given `key` exists
|
||
|
|
// within the `btree_multimap`, returning `true` if so or `false` otherwise.
|
||
|
|
//
|
||
|
|
// Supports heterogeneous lookup, provided that the map is provided a
|
||
|
|
// compatible heterogeneous comparator.
|
||
|
|
using Base::contains;
|
||
|
|
|
||
|
|
// btree_multimap::count()
|
||
|
|
//
|
||
|
|
// template <typename K> size_type count(const K& key) const:
|
||
|
|
//
|
||
|
|
// Returns the number of elements comparing equal to the given `key` within
|
||
|
|
// the `btree_multimap`.
|
||
|
|
//
|
||
|
|
// Supports heterogeneous lookup, provided that the map is provided a
|
||
|
|
// compatible heterogeneous comparator.
|
||
|
|
using Base::count;
|
||
|
|
|
||
|
|
// btree_multimap::equal_range()
|
||
|
|
//
|
||
|
|
// Returns a half-open range [first, last), defined by a `std::pair` of two
|
||
|
|
// iterators, containing all elements with the passed key in the
|
||
|
|
// `btree_multimap`.
|
||
|
|
using Base::equal_range;
|
||
|
|
|
||
|
|
// btree_multimap::find()
|
||
|
|
//
|
||
|
|
// template <typename K> iterator find(const K& key):
|
||
|
|
// template <typename K> const_iterator find(const K& key) const:
|
||
|
|
//
|
||
|
|
// Finds an element with the passed `key` within the `btree_multimap`.
|
||
|
|
//
|
||
|
|
// Supports heterogeneous lookup, provided that the map is provided a
|
||
|
|
// compatible heterogeneous comparator.
|
||
|
|
using Base::find;
|
||
|
|
|
||
|
|
// btree_multimap::get_allocator()
|
||
|
|
//
|
||
|
|
// Returns the allocator function associated with this `btree_multimap`.
|
||
|
|
using Base::get_allocator;
|
||
|
|
|
||
|
|
// btree_multimap::key_comp();
|
||
|
|
//
|
||
|
|
// Returns the key comparator associated with this `btree_multimap`.
|
||
|
|
using Base::key_comp;
|
||
|
|
|
||
|
|
// btree_multimap::value_comp();
|
||
|
|
//
|
||
|
|
// Returns the value comparator associated with this `btree_multimap`.
|
||
|
|
using Base::value_comp;
|
||
|
|
};
|
||
|
|
|
||
|
|
// absl::swap(absl::btree_multimap<>, absl::btree_multimap<>)
|
||
|
|
//
|
||
|
|
// Swaps the contents of two `absl::btree_multimap` containers.
|
||
|
|
template <typename K, typename V, typename C, typename A>
|
||
|
|
void swap(btree_multimap<K, V, C, A> &x, btree_multimap<K, V, C, A> &y) {
|
||
|
|
return x.swap(y);
|
||
|
|
}
|
||
|
|
|
||
|
|
// absl::erase_if(absl::btree_multimap<>, Pred)
|
||
|
|
//
|
||
|
|
// Erases all elements that satisfy the predicate pred from the container.
|
||
|
|
template <typename K, typename V, typename C, typename A, typename Pred>
|
||
|
|
void erase_if(btree_multimap<K, V, C, A> &map, Pred pred) {
|
||
|
|
for (auto it = map.begin(); it != map.end();) {
|
||
|
|
if (pred(*it)) {
|
||
|
|
it = map.erase(it);
|
||
|
|
} else {
|
||
|
|
++it;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
ABSL_NAMESPACE_END
|
||
|
|
} // namespace absl
|
||
|
|
|
||
|
|
#endif // ABSL_CONTAINER_BTREE_MAP_H_
|