871 lines
31 KiB
C++
871 lines
31 KiB
C++
// Copyright 2018 The Abseil Authors.
|
|
//
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// https://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
//
|
|
// -----------------------------------------------------------------------------
|
|
// File: btree_map.h
|
|
// -----------------------------------------------------------------------------
|
|
//
|
|
// This header file defines B-tree maps: sorted associative containers mapping
|
|
// keys to values.
|
|
//
|
|
// * `absl::btree_map<>`
|
|
// * `absl::btree_multimap<>`
|
|
//
|
|
// These B-tree types are similar to the corresponding types in the STL
|
|
// (`std::map` and `std::multimap`) and generally conform to the STL interfaces
|
|
// of those types. However, because they are implemented using B-trees, they
|
|
// are more efficient in most situations.
|
|
//
|
|
// Unlike `std::map` and `std::multimap`, which are commonly implemented using
|
|
// red-black tree nodes, B-tree maps use more generic B-tree nodes able to hold
|
|
// multiple values per node. Holding multiple values per node often makes
|
|
// B-tree maps perform better than their `std::map` counterparts, because
|
|
// multiple entries can be checked within the same cache hit.
|
|
//
|
|
// However, these types should not be considered drop-in replacements for
|
|
// `std::map` and `std::multimap` as there are some API differences, which are
|
|
// noted in this header file. The most consequential differences with respect to
|
|
// migrating to b-tree from the STL types are listed in the next paragraph.
|
|
// Other API differences are minor.
|
|
//
|
|
// Importantly, insertions and deletions may invalidate outstanding iterators,
|
|
// pointers, and references to elements. Such invalidations are typically only
|
|
// an issue if insertion and deletion operations are interleaved with the use of
|
|
// more than one iterator, pointer, or reference simultaneously. For this
|
|
// reason, `insert()` and `erase()` return a valid iterator at the current
|
|
// position. Another important difference is that key-types must be
|
|
// copy-constructible.
|
|
|
|
#ifndef ABSL_CONTAINER_BTREE_MAP_H_
|
|
#define ABSL_CONTAINER_BTREE_MAP_H_
|
|
|
|
#include "absl/container/internal/btree.h" // IWYU pragma: export
|
|
#include "absl/container/internal/btree_container.h" // IWYU pragma: export
|
|
|
|
namespace absl {
|
|
ABSL_NAMESPACE_BEGIN
|
|
|
|
namespace container_internal {
|
|
|
|
template <typename Key, typename Data, typename Compare, typename Alloc,
|
|
int TargetNodeSize, bool Multi>
|
|
struct map_params;
|
|
|
|
} // namespace container_internal
|
|
|
|
// absl::btree_map<>
|
|
//
|
|
// An `absl::btree_map<K, V>` is an ordered associative container of
|
|
// unique keys and associated values designed to be a more efficient replacement
|
|
// for `std::map` (in most cases).
|
|
//
|
|
// Keys are sorted using an (optional) comparison function, which defaults to
|
|
// `std::less<K>`.
|
|
//
|
|
// An `absl::btree_map<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_map<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_map
|
|
: public container_internal::btree_map_container<
|
|
container_internal::btree<container_internal::map_params<
|
|
Key, Value, Compare, Alloc, /*TargetNodeSize=*/256,
|
|
/*Multi=*/false>>> {
|
|
using Base = typename btree_map::btree_map_container;
|
|
|
|
public:
|
|
// Constructors and Assignment Operators
|
|
//
|
|
// A `btree_map` supports the same overload set as `std::map`
|
|
// for construction and assignment:
|
|
//
|
|
// * Default constructor
|
|
//
|
|
// absl::btree_map<int, std::string> map1;
|
|
//
|
|
// * Initializer List constructor
|
|
//
|
|
// absl::btree_map<int, std::string> map2 =
|
|
// {{1, "huey"}, {2, "dewey"}, {3, "louie"},};
|
|
//
|
|
// * Copy constructor
|
|
//
|
|
// absl::btree_map<int, std::string> map3(map2);
|
|
//
|
|
// * Copy assignment operator
|
|
//
|
|
// absl::btree_map<int, std::string> map4;
|
|
// map4 = map3;
|
|
//
|
|
// * Move constructor
|
|
//
|
|
// // Move is guaranteed efficient
|
|
// absl::btree_map<int, std::string> map5(std::move(map4));
|
|
//
|
|
// * Move assignment operator
|
|
//
|
|
// // May be efficient if allocators are compatible
|
|
// absl::btree_map<int, std::string> map6;
|
|
// map6 = std::move(map5);
|
|
//
|
|
// * Range constructor
|
|
//
|
|
// std::vector<std::pair<int, std::string>> v = {{1, "a"}, {2, "b"}};
|
|
// absl::btree_map<int, std::string> map7(v.begin(), v.end());
|
|
btree_map() {}
|
|
using Base::Base;
|
|
|
|
// btree_map::begin()
|
|
//
|
|
// Returns an iterator to the beginning of the `btree_map`.
|
|
using Base::begin;
|
|
|
|
// btree_map::cbegin()
|
|
//
|
|
// Returns a const iterator to the beginning of the `btree_map`.
|
|
using Base::cbegin;
|
|
|
|
// btree_map::end()
|
|
//
|
|
// Returns an iterator to the end of the `btree_map`.
|
|
using Base::end;
|
|
|
|
// btree_map::cend()
|
|
//
|
|
// Returns a const iterator to the end of the `btree_map`.
|
|
using Base::cend;
|
|
|
|
// btree_map::empty()
|
|
//
|
|
// Returns whether or not the `btree_map` is empty.
|
|
using Base::empty;
|
|
|
|
// btree_map::max_size()
|
|
//
|
|
// Returns the largest theoretical possible number of elements within a
|
|
// `btree_map` under current memory constraints. This value can be thought
|
|
// of as the largest value of `std::distance(begin(), end())` for a
|
|
// `btree_map<Key, T>`.
|
|
using Base::max_size;
|
|
|
|
// btree_map::size()
|
|
//
|
|
// Returns the number of elements currently within the `btree_map`.
|
|
using Base::size;
|
|
|
|
// btree_map::clear()
|
|
//
|
|
// Removes all elements from the `btree_map`. Invalidates any references,
|
|
// pointers, or iterators referring to contained elements.
|
|
using Base::clear;
|
|
|
|
// btree_map::erase()
|
|
//
|
|
// Erases elements within the `btree_map`. 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_map`, 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 element with the matching key, if it exists, returning the
|
|
// number of elements erased (0 or 1).
|
|
using Base::erase;
|
|
|
|
// btree_map::insert()
|
|
//
|
|
// Inserts an element of the specified value into the `btree_map`,
|
|
// returning an iterator pointing to the newly inserted element, provided that
|
|
// an element with the given key does not already exist. If an insertion
|
|
// occurs, any references, pointers, or iterators are invalidated.
|
|
// Overloads are listed below.
|
|
//
|
|
// std::pair<iterator,bool> insert(const value_type& value):
|
|
//
|
|
// Inserts a value into the `btree_map`. Returns a pair consisting of an
|
|
// iterator to the inserted element (or to the element that prevented the
|
|
// insertion) and a bool denoting whether the insertion took place.
|
|
//
|
|
// std::pair<iterator,bool> insert(value_type&& value):
|
|
//
|
|
// Inserts a moveable value into the `btree_map`. Returns a pair
|
|
// consisting of an iterator to the inserted element (or to the element that
|
|
// prevented the insertion) and a bool denoting whether the insertion took
|
|
// place.
|
|
//
|
|
// 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, or to the existing element that prevented the
|
|
// insertion.
|
|
//
|
|
// 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_map::insert_or_assign()
|
|
//
|
|
// Inserts an element of the specified value into the `btree_map` provided
|
|
// that a value with the given key does not already exist, or replaces the
|
|
// corresponding mapped type with the forwarded `obj` argument if a key for
|
|
// that value already exists, returning an iterator pointing to the newly
|
|
// inserted element. Overloads are listed below.
|
|
//
|
|
// pair<iterator, bool> insert_or_assign(const key_type& k, M&& obj):
|
|
// pair<iterator, bool> insert_or_assign(key_type&& k, M&& obj):
|
|
//
|
|
// Inserts/Assigns (or moves) the element of the specified key into the
|
|
// `btree_map`. If the returned bool is true, insertion took place, and if
|
|
// it's false, assignment took place.
|
|
//
|
|
// iterator insert_or_assign(const_iterator hint,
|
|
// const key_type& k, M&& obj):
|
|
// iterator insert_or_assign(const_iterator hint, key_type&& k, M&& obj):
|
|
//
|
|
// Inserts/Assigns (or moves) the element of the specified key into the
|
|
// `btree_map` using the position of `hint` as a non-binding suggestion
|
|
// for where to begin the insertion search.
|
|
using Base::insert_or_assign;
|
|
|
|
// btree_map::emplace()
|
|
//
|
|
// Inserts an element of the specified value by constructing it in-place
|
|
// within the `btree_map`, provided that no element with the given key
|
|
// already exists.
|
|
//
|
|
// The element may be constructed even if there already is an element with the
|
|
// key in the container, in which case the newly constructed element will be
|
|
// destroyed immediately. Prefer `try_emplace()` unless your key is not
|
|
// copyable or moveable.
|
|
//
|
|
// If an insertion occurs, any references, pointers, or iterators are
|
|
// invalidated.
|
|
using Base::emplace;
|
|
|
|
// btree_map::emplace_hint()
|
|
//
|
|
// Inserts an element of the specified value by constructing it in-place
|
|
// within the `btree_map`, using the position of `hint` as a non-binding
|
|
// suggestion for where to begin the insertion search, and only inserts
|
|
// provided that no element with the given key already exists.
|
|
//
|
|
// The element may be constructed even if there already is an element with the
|
|
// key in the container, in which case the newly constructed element will be
|
|
// destroyed immediately. Prefer `try_emplace()` unless your key is not
|
|
// copyable or moveable.
|
|
//
|
|
// If an insertion occurs, any references, pointers, or iterators are
|
|
// invalidated.
|
|
using Base::emplace_hint;
|
|
|
|
// btree_map::try_emplace()
|
|
//
|
|
// Inserts an element of the specified value by constructing it in-place
|
|
// within the `btree_map`, provided that no element with the given key
|
|
// already exists. Unlike `emplace()`, if an element with the given key
|
|
// already exists, we guarantee that no element is constructed.
|
|
//
|
|
// If an insertion occurs, any references, pointers, or iterators are
|
|
// invalidated.
|
|
//
|
|
// Overloads are listed below.
|
|
//
|
|
// std::pair<iterator, bool> try_emplace(const key_type& k, Args&&... args):
|
|
// std::pair<iterator, bool> try_emplace(key_type&& k, Args&&... args):
|
|
//
|
|
// Inserts (via copy or move) the element of the specified key into the
|
|
// `btree_map`.
|
|
//
|
|
// iterator try_emplace(const_iterator hint,
|
|
// const key_type& k, Args&&... args):
|
|
// iterator try_emplace(const_iterator hint, key_type&& k, Args&&... args):
|
|
//
|
|
// Inserts (via copy or move) the element of the specified key into the
|
|
// `btree_map` using the position of `hint` as a non-binding suggestion
|
|
// for where to begin the insertion search.
|
|
using Base::try_emplace;
|
|
|
|
// btree_map::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_map`
|
|
// 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_map::merge()
|
|
//
|
|
// Extracts elements from a given `source` btree_map into this
|
|
// `btree_map`. If the destination `btree_map` already contains an
|
|
// element with an equivalent key, that element is not extracted.
|
|
using Base::merge;
|
|
|
|
// btree_map::swap(btree_map& other)
|
|
//
|
|
// Exchanges the contents of this `btree_map` with those of the `other`
|
|
// btree_map, avoiding invocation of any move, copy, or swap operations on
|
|
// 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 has 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 has 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 has a compatible
|
|
// heterogeneous comparator.
|
|
using Base::find;
|
|
|
|
// btree_map::lower_bound()
|
|
//
|
|
// template <typename K> iterator lower_bound(const K& key):
|
|
// template <typename K> const_iterator lower_bound(const K& key) const:
|
|
//
|
|
// Finds the first element with a key that is not less than `key` within the
|
|
// `btree_map`.
|
|
//
|
|
// Supports heterogeneous lookup, provided that the map has a compatible
|
|
// heterogeneous comparator.
|
|
using Base::lower_bound;
|
|
|
|
// btree_map::upper_bound()
|
|
//
|
|
// template <typename K> iterator upper_bound(const K& key):
|
|
// template <typename K> const_iterator upper_bound(const K& key) const:
|
|
//
|
|
// Finds the first element with a key that is greater than `key` within the
|
|
// `btree_map`.
|
|
//
|
|
// Supports heterogeneous lookup, provided that the map has a compatible
|
|
// heterogeneous comparator.
|
|
using Base::upper_bound;
|
|
|
|
// 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.
|
|
// Returns the number of erased elements.
|
|
template <typename K, typename V, typename C, typename A, typename Pred>
|
|
typename btree_map<K, V, C, A>::size_type erase_if(
|
|
btree_map<K, V, C, A> &map, Pred pred) {
|
|
return container_internal::btree_access::erase_if(map, std::move(pred));
|
|
}
|
|
|
|
// 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 all elements from a given `source` btree_multimap into this
|
|
// `btree_multimap`.
|
|
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 has 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 has 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 has a compatible
|
|
// heterogeneous comparator.
|
|
using Base::find;
|
|
|
|
// btree_multimap::lower_bound()
|
|
//
|
|
// template <typename K> iterator lower_bound(const K& key):
|
|
// template <typename K> const_iterator lower_bound(const K& key) const:
|
|
//
|
|
// Finds the first element with a key that is not less than `key` within the
|
|
// `btree_multimap`.
|
|
//
|
|
// Supports heterogeneous lookup, provided that the map has a compatible
|
|
// heterogeneous comparator.
|
|
using Base::lower_bound;
|
|
|
|
// btree_multimap::upper_bound()
|
|
//
|
|
// template <typename K> iterator upper_bound(const K& key):
|
|
// template <typename K> const_iterator upper_bound(const K& key) const:
|
|
//
|
|
// Finds the first element with a key that is greater than `key` within the
|
|
// `btree_multimap`.
|
|
//
|
|
// Supports heterogeneous lookup, provided that the map has a compatible
|
|
// heterogeneous comparator.
|
|
using Base::upper_bound;
|
|
|
|
// 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.
|
|
// Returns the number of erased elements.
|
|
template <typename K, typename V, typename C, typename A, typename Pred>
|
|
typename btree_multimap<K, V, C, A>::size_type erase_if(
|
|
btree_multimap<K, V, C, A> &map, Pred pred) {
|
|
return container_internal::btree_access::erase_if(map, std::move(pred));
|
|
}
|
|
|
|
namespace container_internal {
|
|
|
|
// A parameters structure for holding the type parameters for a btree_map.
|
|
// Compare and Alloc should be nothrow copy-constructible.
|
|
template <typename Key, typename Data, typename Compare, typename Alloc,
|
|
int TargetNodeSize, bool Multi>
|
|
struct map_params : common_params<Key, Compare, Alloc, TargetNodeSize, Multi,
|
|
map_slot_policy<Key, Data>> {
|
|
using super_type = typename map_params::common_params;
|
|
using mapped_type = Data;
|
|
// This type allows us to move keys when it is safe to do so. It is safe
|
|
// for maps in which value_type and mutable_value_type are layout compatible.
|
|
using slot_policy = typename super_type::slot_policy;
|
|
using slot_type = typename super_type::slot_type;
|
|
using value_type = typename super_type::value_type;
|
|
using init_type = typename super_type::init_type;
|
|
|
|
using original_key_compare = typename super_type::original_key_compare;
|
|
// Reference: https://en.cppreference.com/w/cpp/container/map/value_compare
|
|
class value_compare {
|
|
template <typename Params>
|
|
friend class btree;
|
|
|
|
protected:
|
|
explicit value_compare(original_key_compare c) : comp(std::move(c)) {}
|
|
|
|
original_key_compare comp; // NOLINT
|
|
|
|
public:
|
|
auto operator()(const value_type &lhs, const value_type &rhs) const
|
|
-> decltype(comp(lhs.first, rhs.first)) {
|
|
return comp(lhs.first, rhs.first);
|
|
}
|
|
};
|
|
using is_map_container = std::true_type;
|
|
|
|
template <typename V>
|
|
static auto key(const V &value) -> decltype(value.first) {
|
|
return value.first;
|
|
}
|
|
static const Key &key(const slot_type *s) { return slot_policy::key(s); }
|
|
static const Key &key(slot_type *s) { return slot_policy::key(s); }
|
|
// For use in node handle.
|
|
static auto mutable_key(slot_type *s)
|
|
-> decltype(slot_policy::mutable_key(s)) {
|
|
return slot_policy::mutable_key(s);
|
|
}
|
|
static mapped_type &value(value_type *value) { return value->second; }
|
|
};
|
|
|
|
} // namespace container_internal
|
|
|
|
ABSL_NAMESPACE_END
|
|
} // namespace absl
|
|
|
|
#endif // ABSL_CONTAINER_BTREE_MAP_H_
|