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Diffstat (limited to 'third_party/abseil_cpp/absl/container/flat_hash_map.h')
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diff --git a/third_party/abseil_cpp/absl/container/flat_hash_map.h b/third_party/abseil_cpp/absl/container/flat_hash_map.h deleted file mode 100644 index 74def0df0e33..000000000000 --- a/third_party/abseil_cpp/absl/container/flat_hash_map.h +++ /dev/null @@ -1,606 +0,0 @@ -// 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: flat_hash_map.h -// ----------------------------------------------------------------------------- -// -// An `absl::flat_hash_map<K, V>` is an unordered associative container of -// unique keys and associated values designed to be a more efficient replacement -// for `std::unordered_map`. Like `unordered_map`, search, insertion, and -// deletion of map elements can be done as an `O(1)` operation. However, -// `flat_hash_map` (and other unordered associative containers known as the -// collection of Abseil "Swiss tables") contain other optimizations that result -// in both memory and computation advantages. -// -// In most cases, your default choice for a hash map should be a map of type -// `flat_hash_map`. - -#ifndef ABSL_CONTAINER_FLAT_HASH_MAP_H_ -#define ABSL_CONTAINER_FLAT_HASH_MAP_H_ - -#include <cstddef> -#include <new> -#include <type_traits> -#include <utility> - -#include "absl/algorithm/container.h" -#include "absl/container/internal/container_memory.h" -#include "absl/container/internal/hash_function_defaults.h" // IWYU pragma: export -#include "absl/container/internal/raw_hash_map.h" // IWYU pragma: export -#include "absl/memory/memory.h" - -namespace absl { -ABSL_NAMESPACE_BEGIN -namespace container_internal { -template <class K, class V> -struct FlatHashMapPolicy; -} // namespace container_internal - -// ----------------------------------------------------------------------------- -// absl::flat_hash_map -// ----------------------------------------------------------------------------- -// -// An `absl::flat_hash_map<K, V>` is an unordered associative container which -// has been optimized for both speed and memory footprint in most common use -// cases. Its interface is similar to that of `std::unordered_map<K, V>` with -// the following notable differences: -// -// * Requires keys that are CopyConstructible -// * Requires values that are MoveConstructible -// * Supports heterogeneous lookup, through `find()`, `operator[]()` and -// `insert()`, provided that the map is provided a compatible heterogeneous -// hashing function and equality operator. -// * Invalidates any references and pointers to elements within the table after -// `rehash()`. -// * Contains a `capacity()` member function indicating the number of element -// slots (open, deleted, and empty) within the hash map. -// * Returns `void` from the `erase(iterator)` overload. -// -// By default, `flat_hash_map` uses the `absl::Hash` hashing framework. -// All fundamental and Abseil types that support the `absl::Hash` framework have -// a compatible equality operator for comparing insertions into `flat_hash_map`. -// If your type is not yet supported by the `absl::Hash` framework, see -// absl/hash/hash.h for information on extending Abseil hashing to user-defined -// types. -// -// NOTE: A `flat_hash_map` stores its value types directly inside its -// implementation array to avoid memory indirection. Because a `flat_hash_map` -// is designed to move data when rehashed, map values will not retain pointer -// stability. If you require pointer stability, or if your values are large, -// consider using `absl::flat_hash_map<Key, std::unique_ptr<Value>>` instead. -// If your types are not moveable or you require pointer stability for keys, -// consider `absl::node_hash_map`. -// -// Example: -// -// // Create a flat hash map of three strings (that map to strings) -// absl::flat_hash_map<std::string, std::string> ducks = -// {{"a", "huey"}, {"b", "dewey"}, {"c", "louie"}}; -// -// // Insert a new element into the flat hash map -// ducks.insert({"d", "donald"}); -// -// // Force a rehash of the flat hash map -// ducks.rehash(0); -// -// // Find the element with the key "b" -// std::string search_key = "b"; -// auto result = ducks.find(search_key); -// if (result != ducks.end()) { -// std::cout << "Result: " << result->second << std::endl; -// } -template <class K, class V, - class Hash = absl::container_internal::hash_default_hash<K>, - class Eq = absl::container_internal::hash_default_eq<K>, - class Allocator = std::allocator<std::pair<const K, V>>> -class flat_hash_map : public absl::container_internal::raw_hash_map< - absl::container_internal::FlatHashMapPolicy<K, V>, - Hash, Eq, Allocator> { - using Base = typename flat_hash_map::raw_hash_map; - - public: - // Constructors and Assignment Operators - // - // A flat_hash_map supports the same overload set as `std::unordered_map` - // for construction and assignment: - // - // * Default constructor - // - // // No allocation for the table's elements is made. - // absl::flat_hash_map<int, std::string> map1; - // - // * Initializer List constructor - // - // absl::flat_hash_map<int, std::string> map2 = - // {{1, "huey"}, {2, "dewey"}, {3, "louie"},}; - // - // * Copy constructor - // - // absl::flat_hash_map<int, std::string> map3(map2); - // - // * Copy assignment operator - // - // // Hash functor and Comparator are copied as well - // absl::flat_hash_map<int, std::string> map4; - // map4 = map3; - // - // * Move constructor - // - // // Move is guaranteed efficient - // absl::flat_hash_map<int, std::string> map5(std::move(map4)); - // - // * Move assignment operator - // - // // May be efficient if allocators are compatible - // absl::flat_hash_map<int, std::string> map6; - // map6 = std::move(map5); - // - // * Range constructor - // - // std::vector<std::pair<int, std::string>> v = {{1, "a"}, {2, "b"}}; - // absl::flat_hash_map<int, std::string> map7(v.begin(), v.end()); - flat_hash_map() {} - using Base::Base; - - // flat_hash_map::begin() - // - // Returns an iterator to the beginning of the `flat_hash_map`. - using Base::begin; - - // flat_hash_map::cbegin() - // - // Returns a const iterator to the beginning of the `flat_hash_map`. - using Base::cbegin; - - // flat_hash_map::cend() - // - // Returns a const iterator to the end of the `flat_hash_map`. - using Base::cend; - - // flat_hash_map::end() - // - // Returns an iterator to the end of the `flat_hash_map`. - using Base::end; - - // flat_hash_map::capacity() - // - // Returns the number of element slots (assigned, deleted, and empty) - // available within the `flat_hash_map`. - // - // NOTE: this member function is particular to `absl::flat_hash_map` and is - // not provided in the `std::unordered_map` API. - using Base::capacity; - - // flat_hash_map::empty() - // - // Returns whether or not the `flat_hash_map` is empty. - using Base::empty; - - // flat_hash_map::max_size() - // - // Returns the largest theoretical possible number of elements within a - // `flat_hash_map` under current memory constraints. This value can be thought - // of the largest value of `std::distance(begin(), end())` for a - // `flat_hash_map<K, V>`. - using Base::max_size; - - // flat_hash_map::size() - // - // Returns the number of elements currently within the `flat_hash_map`. - using Base::size; - - // flat_hash_map::clear() - // - // Removes all elements from the `flat_hash_map`. Invalidates any references, - // pointers, or iterators referring to contained elements. - // - // NOTE: this operation may shrink the underlying buffer. To avoid shrinking - // the underlying buffer call `erase(begin(), end())`. - using Base::clear; - - // flat_hash_map::erase() - // - // Erases elements within the `flat_hash_map`. Erasing does not trigger a - // rehash. Overloads are listed below. - // - // void erase(const_iterator pos): - // - // Erases the element at `position` of the `flat_hash_map`, returning - // `void`. - // - // NOTE: returning `void` in this case is different than that of STL - // containers in general and `std::unordered_map` in particular (which - // return an iterator to the element following the erased element). If that - // iterator is needed, simply post increment the iterator: - // - // map.erase(it++); - // - // iterator erase(const_iterator first, const_iterator last): - // - // Erases the elements in the open interval [`first`, `last`), returning an - // iterator pointing to `last`. - // - // size_type erase(const key_type& key): - // - // Erases the element with the matching key, if it exists, returning the - // number of elements erased (0 or 1). - using Base::erase; - - // flat_hash_map::insert() - // - // Inserts an element of the specified value into the `flat_hash_map`, - // returning an iterator pointing to the newly inserted element, provided that - // an element with the given key does not already exist. If rehashing occurs - // due to the insertion, all iterators are invalidated. Overloads are listed - // below. - // - // std::pair<iterator,bool> insert(const init_type& value): - // - // Inserts a value into the `flat_hash_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(T&& value): - // std::pair<iterator,bool> insert(init_type&& value): - // - // Inserts a moveable value into the `flat_hash_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 init_type& value): - // iterator insert(const_iterator hint, T&& value): - // iterator insert(const_iterator hint, init_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`). - // - // NOTE: Although the STL does not specify which element may be inserted if - // multiple keys compare equivalently, for `flat_hash_map` we guarantee the - // first match is inserted. - // - // void insert(std::initializer_list<init_type> ilist): - // - // Inserts the elements within the initializer list `ilist`. - // - // NOTE: Although the STL does not specify which element may be inserted if - // multiple keys compare equivalently within the initializer list, for - // `flat_hash_map` we guarantee the first match is inserted. - using Base::insert; - - // flat_hash_map::insert_or_assign() - // - // Inserts an element of the specified value into the `flat_hash_map` provided - // that a value with the given key does not already exist, or replaces it with - // the element value if a key for that value already exists, returning an - // iterator pointing to the newly inserted element. If rehashing occurs due - // to the insertion, all existing iterators are invalidated. Overloads are - // listed below. - // - // pair<iterator, bool> insert_or_assign(const init_type& k, T&& obj): - // pair<iterator, bool> insert_or_assign(init_type&& k, T&& obj): - // - // Inserts/Assigns (or moves) the element of the specified key into the - // `flat_hash_map`. - // - // iterator insert_or_assign(const_iterator hint, - // const init_type& k, T&& obj): - // iterator insert_or_assign(const_iterator hint, init_type&& k, T&& obj): - // - // Inserts/Assigns (or moves) the element of the specified key into the - // `flat_hash_map` using the position of `hint` as a non-binding suggestion - // for where to begin the insertion search. - using Base::insert_or_assign; - - // flat_hash_map::emplace() - // - // Inserts an element of the specified value by constructing it in-place - // within the `flat_hash_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 rehashing occurs due to the insertion, all iterators are invalidated. - using Base::emplace; - - // flat_hash_map::emplace_hint() - // - // Inserts an element of the specified value by constructing it in-place - // within the `flat_hash_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 rehashing occurs due to the insertion, all iterators are invalidated. - using Base::emplace_hint; - - // flat_hash_map::try_emplace() - // - // Inserts an element of the specified value by constructing it in-place - // within the `flat_hash_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 rehashing occurs due to the insertion, all iterators are invalidated. - // Overloads are listed below. - // - // pair<iterator, bool> try_emplace(const key_type& k, Args&&... args): - // pair<iterator, bool> try_emplace(key_type&& k, Args&&... args): - // - // Inserts (via copy or move) the element of the specified key into the - // `flat_hash_map`. - // - // iterator try_emplace(const_iterator hint, - // const init_type& k, Args&&... args): - // iterator try_emplace(const_iterator hint, init_type&& k, Args&&... args): - // - // Inserts (via copy or move) the element of the specified key into the - // `flat_hash_map` using the position of `hint` as a non-binding suggestion - // for where to begin the insertion search. - // - // All `try_emplace()` overloads make the same guarantees regarding rvalue - // arguments as `std::unordered_map::try_emplace()`, namely that these - // functions will not move from rvalue arguments if insertions do not happen. - using Base::try_emplace; - - // flat_hash_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 key,value pair of the element at the indicated position and - // returns a node handle owning that extracted data. - // - // node_type extract(const key_type& x): - // - // Extracts the key,value pair of the element with a key matching the passed - // key value and returns a node handle owning that extracted data. If the - // `flat_hash_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). - using Base::extract; - - // flat_hash_map::merge() - // - // Extracts elements from a given `source` flat hash map into this - // `flat_hash_map`. If the destination `flat_hash_map` already contains an - // element with an equivalent key, that element is not extracted. - using Base::merge; - - // flat_hash_map::swap(flat_hash_map& other) - // - // Exchanges the contents of this `flat_hash_map` with those of the `other` - // flat hash map, avoiding invocation of any move, copy, or swap operations on - // individual elements. - // - // All iterators and references on the `flat_hash_map` remain valid, excepting - // for the past-the-end iterator, which is invalidated. - // - // `swap()` requires that the flat hash map's hashing and key equivalence - // functions be Swappable, and are exchanged using unqualified calls to - // non-member `swap()`. If the map's allocator has - // `std::allocator_traits<allocator_type>::propagate_on_container_swap::value` - // set to `true`, the allocators are also exchanged using an unqualified call - // to non-member `swap()`; otherwise, the allocators are not swapped. - using Base::swap; - - // flat_hash_map::rehash(count) - // - // Rehashes the `flat_hash_map`, setting the number of slots to be at least - // the passed value. If the new number of slots increases the load factor more - // than the current maximum load factor - // (`count` < `size()` / `max_load_factor()`), then the new number of slots - // will be at least `size()` / `max_load_factor()`. - // - // To force a rehash, pass rehash(0). - // - // NOTE: unlike behavior in `std::unordered_map`, references are also - // invalidated upon a `rehash()`. - using Base::rehash; - - // flat_hash_map::reserve(count) - // - // Sets the number of slots in the `flat_hash_map` to the number needed to - // accommodate at least `count` total elements without exceeding the current - // maximum load factor, and may rehash the container if needed. - using Base::reserve; - - // flat_hash_map::at() - // - // Returns a reference to the mapped value of the element with key equivalent - // to the passed key. - using Base::at; - - // flat_hash_map::contains() - // - // Determines whether an element with a key comparing equal to the given `key` - // exists within the `flat_hash_map`, returning `true` if so or `false` - // otherwise. - using Base::contains; - - // flat_hash_map::count(const Key& key) const - // - // Returns the number of elements with a key comparing equal to the given - // `key` within the `flat_hash_map`. note that this function will return - // either `1` or `0` since duplicate keys are not allowed within a - // `flat_hash_map`. - using Base::count; - - // flat_hash_map::equal_range() - // - // Returns a closed range [first, last], defined by a `std::pair` of two - // iterators, containing all elements with the passed key in the - // `flat_hash_map`. - using Base::equal_range; - - // flat_hash_map::find() - // - // Finds an element with the passed `key` within the `flat_hash_map`. - using Base::find; - - // flat_hash_map::operator[]() - // - // Returns a reference to the value mapped to the passed key within the - // `flat_hash_map`, performing an `insert()` if the key does not already - // exist. - // - // If an insertion occurs and results in a rehashing of the container, all - // iterators are invalidated. Otherwise iterators are not affected and - // references are not invalidated. Overloads are listed below. - // - // T& operator[](const Key& key): - // - // Inserts an init_type object constructed in-place if the element with the - // given key does not exist. - // - // T& operator[](Key&& key): - // - // Inserts an init_type object constructed in-place provided that an element - // with the given key does not exist. - using Base::operator[]; - - // flat_hash_map::bucket_count() - // - // Returns the number of "buckets" within the `flat_hash_map`. Note that - // because a flat hash map contains all elements within its internal storage, - // this value simply equals the current capacity of the `flat_hash_map`. - using Base::bucket_count; - - // flat_hash_map::load_factor() - // - // Returns the current load factor of the `flat_hash_map` (the average number - // of slots occupied with a value within the hash map). - using Base::load_factor; - - // flat_hash_map::max_load_factor() - // - // Manages the maximum load factor of the `flat_hash_map`. Overloads are - // listed below. - // - // float flat_hash_map::max_load_factor() - // - // Returns the current maximum load factor of the `flat_hash_map`. - // - // void flat_hash_map::max_load_factor(float ml) - // - // Sets the maximum load factor of the `flat_hash_map` to the passed value. - // - // NOTE: This overload is provided only for API compatibility with the STL; - // `flat_hash_map` will ignore any set load factor and manage its rehashing - // internally as an implementation detail. - using Base::max_load_factor; - - // flat_hash_map::get_allocator() - // - // Returns the allocator function associated with this `flat_hash_map`. - using Base::get_allocator; - - // flat_hash_map::hash_function() - // - // Returns the hashing function used to hash the keys within this - // `flat_hash_map`. - using Base::hash_function; - - // flat_hash_map::key_eq() - // - // Returns the function used for comparing keys equality. - using Base::key_eq; -}; - -// erase_if(flat_hash_map<>, Pred) -// -// Erases all elements that satisfy the predicate `pred` from the container `c`. -template <typename K, typename V, typename H, typename E, typename A, - typename Predicate> -void erase_if(flat_hash_map<K, V, H, E, A>& c, Predicate pred) { - container_internal::EraseIf(pred, &c); -} - -namespace container_internal { - -template <class K, class V> -struct FlatHashMapPolicy { - using slot_policy = container_internal::map_slot_policy<K, V>; - using slot_type = typename slot_policy::slot_type; - using key_type = K; - using mapped_type = V; - using init_type = std::pair</*non const*/ key_type, mapped_type>; - - template <class Allocator, class... Args> - static void construct(Allocator* alloc, slot_type* slot, Args&&... args) { - slot_policy::construct(alloc, slot, std::forward<Args>(args)...); - } - - template <class Allocator> - static void destroy(Allocator* alloc, slot_type* slot) { - slot_policy::destroy(alloc, slot); - } - - template <class Allocator> - static void transfer(Allocator* alloc, slot_type* new_slot, - slot_type* old_slot) { - slot_policy::transfer(alloc, new_slot, old_slot); - } - - template <class F, class... Args> - static decltype(absl::container_internal::DecomposePair( - std::declval<F>(), std::declval<Args>()...)) - apply(F&& f, Args&&... args) { - return absl::container_internal::DecomposePair(std::forward<F>(f), - std::forward<Args>(args)...); - } - - static size_t space_used(const slot_type*) { return 0; } - - static std::pair<const K, V>& element(slot_type* slot) { return slot->value; } - - static V& value(std::pair<const K, V>* kv) { return kv->second; } - static const V& value(const std::pair<const K, V>* kv) { return kv->second; } -}; - -} // namespace container_internal - -namespace container_algorithm_internal { - -// Specialization of trait in absl/algorithm/container.h -template <class Key, class T, class Hash, class KeyEqual, class Allocator> -struct IsUnorderedContainer< - absl::flat_hash_map<Key, T, Hash, KeyEqual, Allocator>> : std::true_type {}; - -} // namespace container_algorithm_internal - -ABSL_NAMESPACE_END -} // namespace absl - -#endif // ABSL_CONTAINER_FLAT_HASH_MAP_H_ |