| // unordered_map implementation -*- C++ -*- |
| |
| // Copyright (C) 2010-2013 Free Software Foundation, Inc. |
| // |
| // This file is part of the GNU ISO C++ Library. This library is free |
| // software; you can redistribute it and/or modify it under the |
| // terms of the GNU General Public License as published by the |
| // Free Software Foundation; either version 3, or (at your option) |
| // any later version. |
| |
| // This library is distributed in the hope that it will be useful, |
| // but WITHOUT ANY WARRANTY; without even the implied warranty of |
| // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| // GNU General Public License for more details. |
| |
| // Under Section 7 of GPL version 3, you are granted additional |
| // permissions described in the GCC Runtime Library Exception, version |
| // 3.1, as published by the Free Software Foundation. |
| |
| // You should have received a copy of the GNU General Public License and |
| // a copy of the GCC Runtime Library Exception along with this program; |
| // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see |
| // <http://www.gnu.org/licenses/>. |
| |
| /** @file bits/unordered_map.h |
| * This is an internal header file, included by other library headers. |
| * Do not attempt to use it directly. @headername{unordered_map} |
| */ |
| |
| #ifndef _UNORDERED_MAP_H |
| #define _UNORDERED_MAP_H |
| |
| namespace std _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_CONTAINER |
| |
| /// Base types for unordered_map. |
| template<bool _Cache> |
| using __umap_traits = __detail::_Hashtable_traits<_Cache, false, true>; |
| |
| template<typename _Key, |
| typename _Tp, |
| typename _Hash = hash<_Key>, |
| typename _Pred = std::equal_to<_Key>, |
| typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >, |
| typename _Tr = __umap_traits<__cache_default<_Key, _Hash>::value>> |
| using __umap_hashtable = _Hashtable<_Key, std::pair<const _Key, _Tp>, |
| _Alloc, __detail::_Select1st, |
| _Pred, _Hash, |
| __detail::_Mod_range_hashing, |
| __detail::_Default_ranged_hash, |
| __detail::_Prime_rehash_policy, _Tr>; |
| |
| /// Base types for unordered_multimap. |
| template<bool _Cache> |
| using __ummap_traits = __detail::_Hashtable_traits<_Cache, false, false>; |
| |
| template<typename _Key, |
| typename _Tp, |
| typename _Hash = hash<_Key>, |
| typename _Pred = std::equal_to<_Key>, |
| typename _Alloc = std::allocator<std::pair<const _Key, _Tp> >, |
| typename _Tr = __ummap_traits<__cache_default<_Key, _Hash>::value>> |
| using __ummap_hashtable = _Hashtable<_Key, std::pair<const _Key, _Tp>, |
| _Alloc, __detail::_Select1st, |
| _Pred, _Hash, |
| __detail::_Mod_range_hashing, |
| __detail::_Default_ranged_hash, |
| __detail::_Prime_rehash_policy, _Tr>; |
| |
| /** |
| * @brief A standard container composed of unique keys (containing |
| * at most one of each key value) that associates values of another type |
| * with the keys. |
| * |
| * @ingroup unordered_associative_containers |
| * |
| * @tparam _Key Type of key objects. |
| * @tparam _Tp Type of mapped objects. |
| * @tparam _Hash Hashing function object type, defaults to hash<_Value>. |
| * @tparam _Pred Predicate function object type, defaults |
| * to equal_to<_Value>. |
| * @tparam _Alloc Allocator type, defaults to allocator<_Key>. |
| * |
| * Meets the requirements of a <a href="tables.html#65">container</a>, and |
| * <a href="tables.html#xx">unordered associative container</a> |
| * |
| * The resulting value type of the container is std::pair<const _Key, _Tp>. |
| * |
| * Base is _Hashtable, dispatched at compile time via template |
| * alias __umap_hashtable. |
| */ |
| template<class _Key, class _Tp, |
| class _Hash = hash<_Key>, |
| class _Pred = std::equal_to<_Key>, |
| class _Alloc = std::allocator<std::pair<const _Key, _Tp> > > |
| class unordered_map : __check_copy_constructible<_Alloc> |
| { |
| typedef __umap_hashtable<_Key, _Tp, _Hash, _Pred, _Alloc> _Hashtable; |
| _Hashtable _M_h; |
| |
| public: |
| // typedefs: |
| //@{ |
| /// Public typedefs. |
| typedef typename _Hashtable::key_type key_type; |
| typedef typename _Hashtable::value_type value_type; |
| typedef typename _Hashtable::mapped_type mapped_type; |
| typedef typename _Hashtable::hasher hasher; |
| typedef typename _Hashtable::key_equal key_equal; |
| typedef typename _Hashtable::allocator_type allocator_type; |
| //@} |
| |
| //@{ |
| /// Iterator-related typedefs. |
| typedef typename allocator_type::pointer pointer; |
| typedef typename allocator_type::const_pointer const_pointer; |
| typedef typename allocator_type::reference reference; |
| typedef typename allocator_type::const_reference const_reference; |
| typedef typename _Hashtable::iterator iterator; |
| typedef typename _Hashtable::const_iterator const_iterator; |
| typedef typename _Hashtable::local_iterator local_iterator; |
| typedef typename _Hashtable::const_local_iterator const_local_iterator; |
| typedef typename _Hashtable::size_type size_type; |
| typedef typename _Hashtable::difference_type difference_type; |
| //@} |
| |
| //construct/destroy/copy |
| |
| /** |
| * @brief Default constructor creates no elements. |
| * @param __n Initial number of buckets. |
| * @param __hf A hash functor. |
| * @param __eql A key equality functor. |
| * @param __a An allocator object. |
| */ |
| explicit |
| unordered_map(size_type __n = 10, |
| const hasher& __hf = hasher(), |
| const key_equal& __eql = key_equal(), |
| const allocator_type& __a = allocator_type()) |
| : _M_h(__n, __hf, __eql, __a) |
| { } |
| |
| /** |
| * @brief Builds an %unordered_map from a range. |
| * @param __first An input iterator. |
| * @param __last An input iterator. |
| * @param __n Minimal initial number of buckets. |
| * @param __hf A hash functor. |
| * @param __eql A key equality functor. |
| * @param __a An allocator object. |
| * |
| * Create an %unordered_map consisting of copies of the elements from |
| * [__first,__last). This is linear in N (where N is |
| * distance(__first,__last)). |
| */ |
| template<typename _InputIterator> |
| unordered_map(_InputIterator __f, _InputIterator __l, |
| size_type __n = 0, |
| const hasher& __hf = hasher(), |
| const key_equal& __eql = key_equal(), |
| const allocator_type& __a = allocator_type()) |
| : _M_h(__f, __l, __n, __hf, __eql, __a) |
| { } |
| |
| /// Copy constructor. |
| unordered_map(const unordered_map&) = default; |
| |
| /// Move constructor. |
| unordered_map(unordered_map&&) = default; |
| |
| /** |
| * @brief Builds an %unordered_map from an initializer_list. |
| * @param __l An initializer_list. |
| * @param __n Minimal initial number of buckets. |
| * @param __hf A hash functor. |
| * @param __eql A key equality functor. |
| * @param __a An allocator object. |
| * |
| * Create an %unordered_map consisting of copies of the elements in the |
| * list. This is linear in N (where N is @a __l.size()). |
| */ |
| unordered_map(initializer_list<value_type> __l, |
| size_type __n = 0, |
| const hasher& __hf = hasher(), |
| const key_equal& __eql = key_equal(), |
| const allocator_type& __a = allocator_type()) |
| : _M_h(__l, __n, __hf, __eql, __a) |
| { } |
| |
| /// Copy assignment operator. |
| unordered_map& |
| operator=(const unordered_map&) = default; |
| |
| /// Move assignment operator. |
| unordered_map& |
| operator=(unordered_map&&) = default; |
| |
| /** |
| * @brief %Unordered_map list assignment operator. |
| * @param __l An initializer_list. |
| * |
| * This function fills an %unordered_map with copies of the elements in |
| * the initializer list @a __l. |
| * |
| * Note that the assignment completely changes the %unordered_map and |
| * that the resulting %unordered_map's size is the same as the number |
| * of elements assigned. Old data may be lost. |
| */ |
| unordered_map& |
| operator=(initializer_list<value_type> __l) |
| { |
| _M_h = __l; |
| return *this; |
| } |
| |
| /// Returns the allocator object with which the %unordered_map was |
| /// constructed. |
| allocator_type |
| get_allocator() const noexcept |
| { return _M_h.get_allocator(); } |
| |
| // size and capacity: |
| |
| /// Returns true if the %unordered_map is empty. |
| bool |
| empty() const noexcept |
| { return _M_h.empty(); } |
| |
| /// Returns the size of the %unordered_map. |
| size_type |
| size() const noexcept |
| { return _M_h.size(); } |
| |
| /// Returns the maximum size of the %unordered_map. |
| size_type |
| max_size() const noexcept |
| { return _M_h.max_size(); } |
| |
| // iterators. |
| |
| /** |
| * Returns a read/write iterator that points to the first element in the |
| * %unordered_map. |
| */ |
| iterator |
| begin() noexcept |
| { return _M_h.begin(); } |
| |
| //@{ |
| /** |
| * Returns a read-only (constant) iterator that points to the first |
| * element in the %unordered_map. |
| */ |
| const_iterator |
| begin() const noexcept |
| { return _M_h.begin(); } |
| |
| const_iterator |
| cbegin() const noexcept |
| { return _M_h.begin(); } |
| //@} |
| |
| /** |
| * Returns a read/write iterator that points one past the last element in |
| * the %unordered_map. |
| */ |
| iterator |
| end() noexcept |
| { return _M_h.end(); } |
| |
| //@{ |
| /** |
| * Returns a read-only (constant) iterator that points one past the last |
| * element in the %unordered_map. |
| */ |
| const_iterator |
| end() const noexcept |
| { return _M_h.end(); } |
| |
| const_iterator |
| cend() const noexcept |
| { return _M_h.end(); } |
| //@} |
| |
| // modifiers. |
| |
| /** |
| * @brief Attempts to build and insert a std::pair into the %unordered_map. |
| * |
| * @param __args Arguments used to generate a new pair instance (see |
| * std::piecewise_contruct for passing arguments to each |
| * part of the pair constructor). |
| * |
| * @return A pair, of which the first element is an iterator that points |
| * to the possibly inserted pair, and the second is a bool that |
| * is true if the pair was actually inserted. |
| * |
| * This function attempts to build and insert a (key, value) %pair into |
| * the %unordered_map. |
| * An %unordered_map relies on unique keys and thus a %pair is only |
| * inserted if its first element (the key) is not already present in the |
| * %unordered_map. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| template<typename... _Args> |
| std::pair<iterator, bool> |
| emplace(_Args&&... __args) |
| { return _M_h.emplace(std::forward<_Args>(__args)...); } |
| |
| /** |
| * @brief Attempts to build and insert a std::pair into the %unordered_map. |
| * |
| * @param __pos An iterator that serves as a hint as to where the pair |
| * should be inserted. |
| * @param __args Arguments used to generate a new pair instance (see |
| * std::piecewise_contruct for passing arguments to each |
| * part of the pair constructor). |
| * @return An iterator that points to the element with key of the |
| * std::pair built from @a __args (may or may not be that |
| * std::pair). |
| * |
| * This function is not concerned about whether the insertion took place, |
| * and thus does not return a boolean like the single-argument emplace() |
| * does. |
| * Note that the first parameter is only a hint and can potentially |
| * improve the performance of the insertion process. A bad hint would |
| * cause no gains in efficiency. |
| * |
| * See |
| * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html |
| * for more on @a hinting. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| template<typename... _Args> |
| iterator |
| emplace_hint(const_iterator __pos, _Args&&... __args) |
| { return _M_h.emplace_hint(__pos, std::forward<_Args>(__args)...); } |
| |
| //@{ |
| /** |
| * @brief Attempts to insert a std::pair into the %unordered_map. |
| |
| * @param __x Pair to be inserted (see std::make_pair for easy |
| * creation of pairs). |
| * |
| * @return A pair, of which the first element is an iterator that |
| * points to the possibly inserted pair, and the second is |
| * a bool that is true if the pair was actually inserted. |
| * |
| * This function attempts to insert a (key, value) %pair into the |
| * %unordered_map. An %unordered_map relies on unique keys and thus a |
| * %pair is only inserted if its first element (the key) is not already |
| * present in the %unordered_map. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| std::pair<iterator, bool> |
| insert(const value_type& __x) |
| { return _M_h.insert(__x); } |
| |
| template<typename _Pair, typename = typename |
| std::enable_if<std::is_constructible<value_type, |
| _Pair&&>::value>::type> |
| std::pair<iterator, bool> |
| insert(_Pair&& __x) |
| { return _M_h.insert(std::move(__x)); } |
| //@} |
| |
| //@{ |
| /** |
| * @brief Attempts to insert a std::pair into the %unordered_map. |
| * @param __hint An iterator that serves as a hint as to where the |
| * pair should be inserted. |
| * @param __x Pair to be inserted (see std::make_pair for easy creation |
| * of pairs). |
| * @return An iterator that points to the element with key of |
| * @a __x (may or may not be the %pair passed in). |
| * |
| * This function is not concerned about whether the insertion took place, |
| * and thus does not return a boolean like the single-argument insert() |
| * does. Note that the first parameter is only a hint and can |
| * potentially improve the performance of the insertion process. A bad |
| * hint would cause no gains in efficiency. |
| * |
| * See |
| * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html |
| * for more on @a hinting. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| iterator |
| insert(const_iterator __hint, const value_type& __x) |
| { return _M_h.insert(__hint, __x); } |
| |
| template<typename _Pair, typename = typename |
| std::enable_if<std::is_constructible<value_type, |
| _Pair&&>::value>::type> |
| iterator |
| insert(const_iterator __hint, _Pair&& __x) |
| { return _M_h.insert(__hint, std::move(__x)); } |
| //@} |
| |
| /** |
| * @brief A template function that attempts to insert a range of |
| * elements. |
| * @param __first Iterator pointing to the start of the range to be |
| * inserted. |
| * @param __last Iterator pointing to the end of the range. |
| * |
| * Complexity similar to that of the range constructor. |
| */ |
| template<typename _InputIterator> |
| void |
| insert(_InputIterator __first, _InputIterator __last) |
| { _M_h.insert(__first, __last); } |
| |
| /** |
| * @brief Attempts to insert a list of elements into the %unordered_map. |
| * @param __l A std::initializer_list<value_type> of elements |
| * to be inserted. |
| * |
| * Complexity similar to that of the range constructor. |
| */ |
| void |
| insert(initializer_list<value_type> __l) |
| { _M_h.insert(__l); } |
| |
| //@{ |
| /** |
| * @brief Erases an element from an %unordered_map. |
| * @param __position An iterator pointing to the element to be erased. |
| * @return An iterator pointing to the element immediately following |
| * @a __position prior to the element being erased. If no such |
| * element exists, end() is returned. |
| * |
| * This function erases an element, pointed to by the given iterator, |
| * from an %unordered_map. |
| * Note that this function only erases the element, and that if the |
| * element is itself a pointer, the pointed-to memory is not touched in |
| * any way. Managing the pointer is the user's responsibility. |
| */ |
| iterator |
| erase(const_iterator __position) |
| { return _M_h.erase(__position); } |
| |
| // LWG 2059. |
| iterator |
| erase(iterator __it) |
| { return _M_h.erase(__it); } |
| //@} |
| |
| /** |
| * @brief Erases elements according to the provided key. |
| * @param __x Key of element to be erased. |
| * @return The number of elements erased. |
| * |
| * This function erases all the elements located by the given key from |
| * an %unordered_map. For an %unordered_map the result of this function |
| * can only be 0 (not present) or 1 (present). |
| * Note that this function only erases the element, and that if the |
| * element is itself a pointer, the pointed-to memory is not touched in |
| * any way. Managing the pointer is the user's responsibility. |
| */ |
| size_type |
| erase(const key_type& __x) |
| { return _M_h.erase(__x); } |
| |
| /** |
| * @brief Erases a [__first,__last) range of elements from an |
| * %unordered_map. |
| * @param __first Iterator pointing to the start of the range to be |
| * erased. |
| * @param __last Iterator pointing to the end of the range to |
| * be erased. |
| * @return The iterator @a __last. |
| * |
| * This function erases a sequence of elements from an %unordered_map. |
| * Note that this function only erases the elements, and that if |
| * the element is itself a pointer, the pointed-to memory is not touched |
| * in any way. Managing the pointer is the user's responsibility. |
| */ |
| iterator |
| erase(const_iterator __first, const_iterator __last) |
| { return _M_h.erase(__first, __last); } |
| |
| /** |
| * Erases all elements in an %unordered_map. |
| * Note that this function only erases the elements, and that if the |
| * elements themselves are pointers, the pointed-to memory is not touched |
| * in any way. Managing the pointer is the user's responsibility. |
| */ |
| void |
| clear() noexcept |
| { _M_h.clear(); } |
| |
| /** |
| * @brief Swaps data with another %unordered_map. |
| * @param __x An %unordered_map of the same element and allocator |
| * types. |
| * |
| * This exchanges the elements between two %unordered_map in constant time. |
| * Note that the global std::swap() function is specialized such that |
| * std::swap(m1,m2) will feed to this function. |
| */ |
| void |
| swap(unordered_map& __x) |
| { _M_h.swap(__x._M_h); } |
| |
| // observers. |
| |
| /// Returns the hash functor object with which the %unordered_map was |
| /// constructed. |
| hasher |
| hash_function() const |
| { return _M_h.hash_function(); } |
| |
| /// Returns the key comparison object with which the %unordered_map was |
| /// constructed. |
| key_equal |
| key_eq() const |
| { return _M_h.key_eq(); } |
| |
| // lookup. |
| |
| //@{ |
| /** |
| * @brief Tries to locate an element in an %unordered_map. |
| * @param __x Key to be located. |
| * @return Iterator pointing to sought-after element, or end() if not |
| * found. |
| * |
| * This function takes a key and tries to locate the element with which |
| * the key matches. If successful the function returns an iterator |
| * pointing to the sought after element. If unsuccessful it returns the |
| * past-the-end ( @c end() ) iterator. |
| */ |
| iterator |
| find(const key_type& __x) |
| { return _M_h.find(__x); } |
| |
| const_iterator |
| find(const key_type& __x) const |
| { return _M_h.find(__x); } |
| //@} |
| |
| /** |
| * @brief Finds the number of elements. |
| * @param __x Key to count. |
| * @return Number of elements with specified key. |
| * |
| * This function only makes sense for %unordered_multimap; for |
| * %unordered_map the result will either be 0 (not present) or 1 |
| * (present). |
| */ |
| size_type |
| count(const key_type& __x) const |
| { return _M_h.count(__x); } |
| |
| //@{ |
| /** |
| * @brief Finds a subsequence matching given key. |
| * @param __x Key to be located. |
| * @return Pair of iterators that possibly points to the subsequence |
| * matching given key. |
| * |
| * This function probably only makes sense for %unordered_multimap. |
| */ |
| std::pair<iterator, iterator> |
| equal_range(const key_type& __x) |
| { return _M_h.equal_range(__x); } |
| |
| std::pair<const_iterator, const_iterator> |
| equal_range(const key_type& __x) const |
| { return _M_h.equal_range(__x); } |
| //@} |
| |
| //@{ |
| /** |
| * @brief Subscript ( @c [] ) access to %unordered_map data. |
| * @param __k The key for which data should be retrieved. |
| * @return A reference to the data of the (key,data) %pair. |
| * |
| * Allows for easy lookup with the subscript ( @c [] )operator. Returns |
| * data associated with the key specified in subscript. If the key does |
| * not exist, a pair with that key is created using default values, which |
| * is then returned. |
| * |
| * Lookup requires constant time. |
| */ |
| mapped_type& |
| operator[](const key_type& __k) |
| { return _M_h[__k]; } |
| |
| mapped_type& |
| operator[](key_type&& __k) |
| { return _M_h[std::move(__k)]; } |
| //@} |
| |
| //@{ |
| /** |
| * @brief Access to %unordered_map data. |
| * @param __k The key for which data should be retrieved. |
| * @return A reference to the data whose key is equal to @a __k, if |
| * such a data is present in the %unordered_map. |
| * @throw std::out_of_range If no such data is present. |
| */ |
| mapped_type& |
| at(const key_type& __k) |
| { return _M_h.at(__k); } |
| |
| const mapped_type& |
| at(const key_type& __k) const |
| { return _M_h.at(__k); } |
| //@} |
| |
| // bucket interface. |
| |
| /// Returns the number of buckets of the %unordered_map. |
| size_type |
| bucket_count() const noexcept |
| { return _M_h.bucket_count(); } |
| |
| /// Returns the maximum number of buckets of the %unordered_map. |
| size_type |
| max_bucket_count() const noexcept |
| { return _M_h.max_bucket_count(); } |
| |
| /* |
| * @brief Returns the number of elements in a given bucket. |
| * @param __n A bucket index. |
| * @return The number of elements in the bucket. |
| */ |
| size_type |
| bucket_size(size_type __n) const |
| { return _M_h.bucket_size(__n); } |
| |
| /* |
| * @brief Returns the bucket index of a given element. |
| * @param __key A key instance. |
| * @return The key bucket index. |
| */ |
| size_type |
| bucket(const key_type& __key) const |
| { return _M_h.bucket(__key); } |
| |
| /** |
| * @brief Returns a read/write iterator pointing to the first bucket |
| * element. |
| * @param __n The bucket index. |
| * @return A read/write local iterator. |
| */ |
| local_iterator |
| begin(size_type __n) |
| { return _M_h.begin(__n); } |
| |
| //@{ |
| /** |
| * @brief Returns a read-only (constant) iterator pointing to the first |
| * bucket element. |
| * @param __n The bucket index. |
| * @return A read-only local iterator. |
| */ |
| const_local_iterator |
| begin(size_type __n) const |
| { return _M_h.begin(__n); } |
| |
| const_local_iterator |
| cbegin(size_type __n) const |
| { return _M_h.cbegin(__n); } |
| //@} |
| |
| /** |
| * @brief Returns a read/write iterator pointing to one past the last |
| * bucket elements. |
| * @param __n The bucket index. |
| * @return A read/write local iterator. |
| */ |
| local_iterator |
| end(size_type __n) |
| { return _M_h.end(__n); } |
| |
| //@{ |
| /** |
| * @brief Returns a read-only (constant) iterator pointing to one past |
| * the last bucket elements. |
| * @param __n The bucket index. |
| * @return A read-only local iterator. |
| */ |
| const_local_iterator |
| end(size_type __n) const |
| { return _M_h.end(__n); } |
| |
| const_local_iterator |
| cend(size_type __n) const |
| { return _M_h.cend(__n); } |
| //@} |
| |
| // hash policy. |
| |
| /// Returns the average number of elements per bucket. |
| float |
| load_factor() const noexcept |
| { return _M_h.load_factor(); } |
| |
| /// Returns a positive number that the %unordered_map tries to keep the |
| /// load factor less than or equal to. |
| float |
| max_load_factor() const noexcept |
| { return _M_h.max_load_factor(); } |
| |
| /** |
| * @brief Change the %unordered_map maximum load factor. |
| * @param __z The new maximum load factor. |
| */ |
| void |
| max_load_factor(float __z) |
| { _M_h.max_load_factor(__z); } |
| |
| /** |
| * @brief May rehash the %unordered_map. |
| * @param __n The new number of buckets. |
| * |
| * Rehash will occur only if the new number of buckets respect the |
| * %unordered_map maximum load factor. |
| */ |
| void |
| rehash(size_type __n) |
| { _M_h.rehash(__n); } |
| |
| /** |
| * @brief Prepare the %unordered_map for a specified number of |
| * elements. |
| * @param __n Number of elements required. |
| * |
| * Same as rehash(ceil(n / max_load_factor())). |
| */ |
| void |
| reserve(size_type __n) |
| { _M_h.reserve(__n); } |
| |
| template<typename _Key1, typename _Tp1, typename _Hash1, typename _Pred1, |
| typename _Alloc1> |
| friend bool |
| operator==(const unordered_map<_Key1, _Tp1, _Hash1, _Pred1, _Alloc1>&, |
| const unordered_map<_Key1, _Tp1, _Hash1, _Pred1, _Alloc1>&); |
| }; |
| |
| /** |
| * @brief A standard container composed of equivalent keys |
| * (possibly containing multiple of each key value) that associates |
| * values of another type with the keys. |
| * |
| * @ingroup unordered_associative_containers |
| * |
| * @tparam _Key Type of key objects. |
| * @tparam _Tp Type of mapped objects. |
| * @tparam _Hash Hashing function object type, defaults to hash<_Value>. |
| * @tparam _Pred Predicate function object type, defaults |
| * to equal_to<_Value>. |
| * @tparam _Alloc Allocator type, defaults to allocator<_Key>. |
| * |
| * Meets the requirements of a <a href="tables.html#65">container</a>, and |
| * <a href="tables.html#xx">unordered associative container</a> |
| * |
| * The resulting value type of the container is std::pair<const _Key, _Tp>. |
| * |
| * Base is _Hashtable, dispatched at compile time via template |
| * alias __ummap_hashtable. |
| */ |
| template<class _Key, class _Tp, |
| class _Hash = hash<_Key>, |
| class _Pred = std::equal_to<_Key>, |
| class _Alloc = std::allocator<std::pair<const _Key, _Tp> > > |
| class unordered_multimap : __check_copy_constructible<_Alloc> |
| { |
| typedef __ummap_hashtable<_Key, _Tp, _Hash, _Pred, _Alloc> _Hashtable; |
| _Hashtable _M_h; |
| |
| public: |
| // typedefs: |
| //@{ |
| /// Public typedefs. |
| typedef typename _Hashtable::key_type key_type; |
| typedef typename _Hashtable::value_type value_type; |
| typedef typename _Hashtable::mapped_type mapped_type; |
| typedef typename _Hashtable::hasher hasher; |
| typedef typename _Hashtable::key_equal key_equal; |
| typedef typename _Hashtable::allocator_type allocator_type; |
| //@} |
| |
| //@{ |
| /// Iterator-related typedefs. |
| typedef typename allocator_type::pointer pointer; |
| typedef typename allocator_type::const_pointer const_pointer; |
| typedef typename allocator_type::reference reference; |
| typedef typename allocator_type::const_reference const_reference; |
| typedef typename _Hashtable::iterator iterator; |
| typedef typename _Hashtable::const_iterator const_iterator; |
| typedef typename _Hashtable::local_iterator local_iterator; |
| typedef typename _Hashtable::const_local_iterator const_local_iterator; |
| typedef typename _Hashtable::size_type size_type; |
| typedef typename _Hashtable::difference_type difference_type; |
| //@} |
| |
| //construct/destroy/copy |
| |
| /** |
| * @brief Default constructor creates no elements. |
| * @param __n Initial number of buckets. |
| * @param __hf A hash functor. |
| * @param __eql A key equality functor. |
| * @param __a An allocator object. |
| */ |
| explicit |
| unordered_multimap(size_type __n = 10, |
| const hasher& __hf = hasher(), |
| const key_equal& __eql = key_equal(), |
| const allocator_type& __a = allocator_type()) |
| : _M_h(__n, __hf, __eql, __a) |
| { } |
| |
| /** |
| * @brief Builds an %unordered_multimap from a range. |
| * @param __first An input iterator. |
| * @param __last An input iterator. |
| * @param __n Minimal initial number of buckets. |
| * @param __hf A hash functor. |
| * @param __eql A key equality functor. |
| * @param __a An allocator object. |
| * |
| * Create an %unordered_multimap consisting of copies of the elements |
| * from [__first,__last). This is linear in N (where N is |
| * distance(__first,__last)). |
| */ |
| template<typename _InputIterator> |
| unordered_multimap(_InputIterator __f, _InputIterator __l, |
| size_type __n = 0, |
| const hasher& __hf = hasher(), |
| const key_equal& __eql = key_equal(), |
| const allocator_type& __a = allocator_type()) |
| : _M_h(__f, __l, __n, __hf, __eql, __a) |
| { } |
| |
| /// Copy constructor. |
| unordered_multimap(const unordered_multimap&) = default; |
| |
| /// Move constructor. |
| unordered_multimap(unordered_multimap&&) = default; |
| |
| /** |
| * @brief Builds an %unordered_multimap from an initializer_list. |
| * @param __l An initializer_list. |
| * @param __n Minimal initial number of buckets. |
| * @param __hf A hash functor. |
| * @param __eql A key equality functor. |
| * @param __a An allocator object. |
| * |
| * Create an %unordered_multimap consisting of copies of the elements in |
| * the list. This is linear in N (where N is @a __l.size()). |
| */ |
| unordered_multimap(initializer_list<value_type> __l, |
| size_type __n = 0, |
| const hasher& __hf = hasher(), |
| const key_equal& __eql = key_equal(), |
| const allocator_type& __a = allocator_type()) |
| : _M_h(__l, __n, __hf, __eql, __a) |
| { } |
| |
| /// Copy assignment operator. |
| unordered_multimap& |
| operator=(const unordered_multimap&) = default; |
| |
| /// Move assignment operator. |
| unordered_multimap& |
| operator=(unordered_multimap&&) = default; |
| |
| /** |
| * @brief %Unordered_multimap list assignment operator. |
| * @param __l An initializer_list. |
| * |
| * This function fills an %unordered_multimap with copies of the elements |
| * in the initializer list @a __l. |
| * |
| * Note that the assignment completely changes the %unordered_multimap |
| * and that the resulting %unordered_multimap's size is the same as the |
| * number of elements assigned. Old data may be lost. |
| */ |
| unordered_multimap& |
| operator=(initializer_list<value_type> __l) |
| { |
| _M_h = __l; |
| return *this; |
| } |
| |
| /// Returns the allocator object with which the %unordered_multimap was |
| /// constructed. |
| allocator_type |
| get_allocator() const noexcept |
| { return _M_h.get_allocator(); } |
| |
| // size and capacity: |
| |
| /// Returns true if the %unordered_multimap is empty. |
| bool |
| empty() const noexcept |
| { return _M_h.empty(); } |
| |
| /// Returns the size of the %unordered_multimap. |
| size_type |
| size() const noexcept |
| { return _M_h.size(); } |
| |
| /// Returns the maximum size of the %unordered_multimap. |
| size_type |
| max_size() const noexcept |
| { return _M_h.max_size(); } |
| |
| // iterators. |
| |
| /** |
| * Returns a read/write iterator that points to the first element in the |
| * %unordered_multimap. |
| */ |
| iterator |
| begin() noexcept |
| { return _M_h.begin(); } |
| |
| //@{ |
| /** |
| * Returns a read-only (constant) iterator that points to the first |
| * element in the %unordered_multimap. |
| */ |
| const_iterator |
| begin() const noexcept |
| { return _M_h.begin(); } |
| |
| const_iterator |
| cbegin() const noexcept |
| { return _M_h.begin(); } |
| //@} |
| |
| /** |
| * Returns a read/write iterator that points one past the last element in |
| * the %unordered_multimap. |
| */ |
| iterator |
| end() noexcept |
| { return _M_h.end(); } |
| |
| //@{ |
| /** |
| * Returns a read-only (constant) iterator that points one past the last |
| * element in the %unordered_multimap. |
| */ |
| const_iterator |
| end() const noexcept |
| { return _M_h.end(); } |
| |
| const_iterator |
| cend() const noexcept |
| { return _M_h.end(); } |
| //@} |
| |
| // modifiers. |
| |
| /** |
| * @brief Attempts to build and insert a std::pair into the |
| * %unordered_multimap. |
| * |
| * @param __args Arguments used to generate a new pair instance (see |
| * std::piecewise_contruct for passing arguments to each |
| * part of the pair constructor). |
| * |
| * @return An iterator that points to the inserted pair. |
| * |
| * This function attempts to build and insert a (key, value) %pair into |
| * the %unordered_multimap. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| template<typename... _Args> |
| iterator |
| emplace(_Args&&... __args) |
| { return _M_h.emplace(std::forward<_Args>(__args)...); } |
| |
| /** |
| * @brief Attempts to build and insert a std::pair into the %unordered_multimap. |
| * |
| * @param __pos An iterator that serves as a hint as to where the pair |
| * should be inserted. |
| * @param __args Arguments used to generate a new pair instance (see |
| * std::piecewise_contruct for passing arguments to each |
| * part of the pair constructor). |
| * @return An iterator that points to the element with key of the |
| * std::pair built from @a __args. |
| * |
| * Note that the first parameter is only a hint and can potentially |
| * improve the performance of the insertion process. A bad hint would |
| * cause no gains in efficiency. |
| * |
| * See |
| * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html |
| * for more on @a hinting. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| template<typename... _Args> |
| iterator |
| emplace_hint(const_iterator __pos, _Args&&... __args) |
| { return _M_h.emplace_hint(__pos, std::forward<_Args>(__args)...); } |
| |
| //@{ |
| /** |
| * @brief Inserts a std::pair into the %unordered_multimap. |
| * @param __x Pair to be inserted (see std::make_pair for easy |
| * creation of pairs). |
| * |
| * @return An iterator that points to the inserted pair. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| iterator |
| insert(const value_type& __x) |
| { return _M_h.insert(__x); } |
| |
| template<typename _Pair, typename = typename |
| std::enable_if<std::is_constructible<value_type, |
| _Pair&&>::value>::type> |
| iterator |
| insert(_Pair&& __x) |
| { return _M_h.insert(std::move(__x)); } |
| //@} |
| |
| //@{ |
| /** |
| * @brief Inserts a std::pair into the %unordered_multimap. |
| * @param __hint An iterator that serves as a hint as to where the |
| * pair should be inserted. |
| * @param __x Pair to be inserted (see std::make_pair for easy creation |
| * of pairs). |
| * @return An iterator that points to the element with key of |
| * @a __x (may or may not be the %pair passed in). |
| * |
| * Note that the first parameter is only a hint and can potentially |
| * improve the performance of the insertion process. A bad hint would |
| * cause no gains in efficiency. |
| * |
| * See |
| * http://gcc.gnu.org/onlinedocs/libstdc++/manual/bk01pt07ch17.html |
| * for more on @a hinting. |
| * |
| * Insertion requires amortized constant time. |
| */ |
| iterator |
| insert(const_iterator __hint, const value_type& __x) |
| { return _M_h.insert(__hint, __x); } |
| |
| template<typename _Pair, typename = typename |
| std::enable_if<std::is_constructible<value_type, |
| _Pair&&>::value>::type> |
| iterator |
| insert(const_iterator __hint, _Pair&& __x) |
| { return _M_h.insert(__hint, std::move(__x)); } |
| //@} |
| |
| /** |
| * @brief A template function that attempts to insert a range of |
| * elements. |
| * @param __first Iterator pointing to the start of the range to be |
| * inserted. |
| * @param __last Iterator pointing to the end of the range. |
| * |
| * Complexity similar to that of the range constructor. |
| */ |
| template<typename _InputIterator> |
| void |
| insert(_InputIterator __first, _InputIterator __last) |
| { _M_h.insert(__first, __last); } |
| |
| /** |
| * @brief Attempts to insert a list of elements into the |
| * %unordered_multimap. |
| * @param __l A std::initializer_list<value_type> of elements |
| * to be inserted. |
| * |
| * Complexity similar to that of the range constructor. |
| */ |
| void |
| insert(initializer_list<value_type> __l) |
| { _M_h.insert(__l); } |
| |
| //@{ |
| /** |
| * @brief Erases an element from an %unordered_multimap. |
| * @param __position An iterator pointing to the element to be erased. |
| * @return An iterator pointing to the element immediately following |
| * @a __position prior to the element being erased. If no such |
| * element exists, end() is returned. |
| * |
| * This function erases an element, pointed to by the given iterator, |
| * from an %unordered_multimap. |
| * Note that this function only erases the element, and that if the |
| * element is itself a pointer, the pointed-to memory is not touched in |
| * any way. Managing the pointer is the user's responsibility. |
| */ |
| iterator |
| erase(const_iterator __position) |
| { return _M_h.erase(__position); } |
| |
| // LWG 2059. |
| iterator |
| erase(iterator __it) |
| { return _M_h.erase(__it); } |
| //@} |
| |
| /** |
| * @brief Erases elements according to the provided key. |
| * @param __x Key of elements to be erased. |
| * @return The number of elements erased. |
| * |
| * This function erases all the elements located by the given key from |
| * an %unordered_multimap. |
| * Note that this function only erases the element, and that if the |
| * element is itself a pointer, the pointed-to memory is not touched in |
| * any way. Managing the pointer is the user's responsibility. |
| */ |
| size_type |
| erase(const key_type& __x) |
| { return _M_h.erase(__x); } |
| |
| /** |
| * @brief Erases a [__first,__last) range of elements from an |
| * %unordered_multimap. |
| * @param __first Iterator pointing to the start of the range to be |
| * erased. |
| * @param __last Iterator pointing to the end of the range to |
| * be erased. |
| * @return The iterator @a __last. |
| * |
| * This function erases a sequence of elements from an |
| * %unordered_multimap. |
| * Note that this function only erases the elements, and that if |
| * the element is itself a pointer, the pointed-to memory is not touched |
| * in any way. Managing the pointer is the user's responsibility. |
| */ |
| iterator |
| erase(const_iterator __first, const_iterator __last) |
| { return _M_h.erase(__first, __last); } |
| |
| /** |
| * Erases all elements in an %unordered_multimap. |
| * Note that this function only erases the elements, and that if the |
| * elements themselves are pointers, the pointed-to memory is not touched |
| * in any way. Managing the pointer is the user's responsibility. |
| */ |
| void |
| clear() noexcept |
| { _M_h.clear(); } |
| |
| /** |
| * @brief Swaps data with another %unordered_multimap. |
| * @param __x An %unordered_multimap of the same element and allocator |
| * types. |
| * |
| * This exchanges the elements between two %unordered_multimap in |
| * constant time. |
| * Note that the global std::swap() function is specialized such that |
| * std::swap(m1,m2) will feed to this function. |
| */ |
| void |
| swap(unordered_multimap& __x) |
| { _M_h.swap(__x._M_h); } |
| |
| // observers. |
| |
| /// Returns the hash functor object with which the %unordered_multimap |
| /// was constructed. |
| hasher |
| hash_function() const |
| { return _M_h.hash_function(); } |
| |
| /// Returns the key comparison object with which the %unordered_multimap |
| /// was constructed. |
| key_equal |
| key_eq() const |
| { return _M_h.key_eq(); } |
| |
| // lookup. |
| |
| //@{ |
| /** |
| * @brief Tries to locate an element in an %unordered_multimap. |
| * @param __x Key to be located. |
| * @return Iterator pointing to sought-after element, or end() if not |
| * found. |
| * |
| * This function takes a key and tries to locate the element with which |
| * the key matches. If successful the function returns an iterator |
| * pointing to the sought after element. If unsuccessful it returns the |
| * past-the-end ( @c end() ) iterator. |
| */ |
| iterator |
| find(const key_type& __x) |
| { return _M_h.find(__x); } |
| |
| const_iterator |
| find(const key_type& __x) const |
| { return _M_h.find(__x); } |
| //@} |
| |
| /** |
| * @brief Finds the number of elements. |
| * @param __x Key to count. |
| * @return Number of elements with specified key. |
| */ |
| size_type |
| count(const key_type& __x) const |
| { return _M_h.count(__x); } |
| |
| //@{ |
| /** |
| * @brief Finds a subsequence matching given key. |
| * @param __x Key to be located. |
| * @return Pair of iterators that possibly points to the subsequence |
| * matching given key. |
| */ |
| std::pair<iterator, iterator> |
| equal_range(const key_type& __x) |
| { return _M_h.equal_range(__x); } |
| |
| std::pair<const_iterator, const_iterator> |
| equal_range(const key_type& __x) const |
| { return _M_h.equal_range(__x); } |
| //@} |
| |
| // bucket interface. |
| |
| /// Returns the number of buckets of the %unordered_multimap. |
| size_type |
| bucket_count() const noexcept |
| { return _M_h.bucket_count(); } |
| |
| /// Returns the maximum number of buckets of the %unordered_multimap. |
| size_type |
| max_bucket_count() const noexcept |
| { return _M_h.max_bucket_count(); } |
| |
| /* |
| * @brief Returns the number of elements in a given bucket. |
| * @param __n A bucket index. |
| * @return The number of elements in the bucket. |
| */ |
| size_type |
| bucket_size(size_type __n) const |
| { return _M_h.bucket_size(__n); } |
| |
| /* |
| * @brief Returns the bucket index of a given element. |
| * @param __key A key instance. |
| * @return The key bucket index. |
| */ |
| size_type |
| bucket(const key_type& __key) const |
| { return _M_h.bucket(__key); } |
| |
| /** |
| * @brief Returns a read/write iterator pointing to the first bucket |
| * element. |
| * @param __n The bucket index. |
| * @return A read/write local iterator. |
| */ |
| local_iterator |
| begin(size_type __n) |
| { return _M_h.begin(__n); } |
| |
| //@{ |
| /** |
| * @brief Returns a read-only (constant) iterator pointing to the first |
| * bucket element. |
| * @param __n The bucket index. |
| * @return A read-only local iterator. |
| */ |
| const_local_iterator |
| begin(size_type __n) const |
| { return _M_h.begin(__n); } |
| |
| const_local_iterator |
| cbegin(size_type __n) const |
| { return _M_h.cbegin(__n); } |
| //@} |
| |
| /** |
| * @brief Returns a read/write iterator pointing to one past the last |
| * bucket elements. |
| * @param __n The bucket index. |
| * @return A read/write local iterator. |
| */ |
| local_iterator |
| end(size_type __n) |
| { return _M_h.end(__n); } |
| |
| //@{ |
| /** |
| * @brief Returns a read-only (constant) iterator pointing to one past |
| * the last bucket elements. |
| * @param __n The bucket index. |
| * @return A read-only local iterator. |
| */ |
| const_local_iterator |
| end(size_type __n) const |
| { return _M_h.end(__n); } |
| |
| const_local_iterator |
| cend(size_type __n) const |
| { return _M_h.cend(__n); } |
| //@} |
| |
| // hash policy. |
| |
| /// Returns the average number of elements per bucket. |
| float |
| load_factor() const noexcept |
| { return _M_h.load_factor(); } |
| |
| /// Returns a positive number that the %unordered_multimap tries to keep |
| /// the load factor less than or equal to. |
| float |
| max_load_factor() const noexcept |
| { return _M_h.max_load_factor(); } |
| |
| /** |
| * @brief Change the %unordered_multimap maximum load factor. |
| * @param __z The new maximum load factor. |
| */ |
| void |
| max_load_factor(float __z) |
| { _M_h.max_load_factor(__z); } |
| |
| /** |
| * @brief May rehash the %unordered_multimap. |
| * @param __n The new number of buckets. |
| * |
| * Rehash will occur only if the new number of buckets respect the |
| * %unordered_multimap maximum load factor. |
| */ |
| void |
| rehash(size_type __n) |
| { _M_h.rehash(__n); } |
| |
| /** |
| * @brief Prepare the %unordered_multimap for a specified number of |
| * elements. |
| * @param __n Number of elements required. |
| * |
| * Same as rehash(ceil(n / max_load_factor())). |
| */ |
| void |
| reserve(size_type __n) |
| { _M_h.reserve(__n); } |
| |
| template<typename _Key1, typename _Tp1, typename _Hash1, typename _Pred1, |
| typename _Alloc1> |
| friend bool |
| operator==(const unordered_multimap<_Key1, _Tp1, |
| _Hash1, _Pred1, _Alloc1>&, |
| const unordered_multimap<_Key1, _Tp1, |
| _Hash1, _Pred1, _Alloc1>&); |
| }; |
| |
| template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
| inline void |
| swap(unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
| unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
| { __x.swap(__y); } |
| |
| template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
| inline void |
| swap(unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
| unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
| { __x.swap(__y); } |
| |
| template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
| inline bool |
| operator==(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
| const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
| { return __x._M_h._M_equal(__y._M_h); } |
| |
| template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
| inline bool |
| operator!=(const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
| const unordered_map<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
| { return !(__x == __y); } |
| |
| template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
| inline bool |
| operator==(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
| const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
| { return __x._M_h._M_equal(__y._M_h); } |
| |
| template<class _Key, class _Tp, class _Hash, class _Pred, class _Alloc> |
| inline bool |
| operator!=(const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __x, |
| const unordered_multimap<_Key, _Tp, _Hash, _Pred, _Alloc>& __y) |
| { return !(__x == __y); } |
| |
| _GLIBCXX_END_NAMESPACE_CONTAINER |
| } // namespace std |
| |
| #endif /* _UNORDERED_MAP_H */ |
