libstdc++
hashtable_policy.h
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00001 // Internal policy header for unordered_set and unordered_map -*- C++ -*-
00002 
00003 // Copyright (C) 2010-2013 Free Software Foundation, Inc.
00004 //
00005 // This file is part of the GNU ISO C++ Library.  This library is free
00006 // software; you can redistribute it and/or modify it under the
00007 // terms of the GNU General Public License as published by the
00008 // Free Software Foundation; either version 3, or (at your option)
00009 // any later version.
00010 
00011 // This library is distributed in the hope that it will be useful,
00012 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00013 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00014 // GNU General Public License for more details.
00015 
00016 // Under Section 7 of GPL version 3, you are granted additional
00017 // permissions described in the GCC Runtime Library Exception, version
00018 // 3.1, as published by the Free Software Foundation.
00019 
00020 // You should have received a copy of the GNU General Public License and
00021 // a copy of the GCC Runtime Library Exception along with this program;
00022 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
00023 // <http://www.gnu.org/licenses/>.
00024 
00025 /** @file bits/hashtable_policy.h
00026  *  This is an internal header file, included by other library headers.
00027  *  Do not attempt to use it directly.
00028  *  @headername{unordered_map,unordered_set}
00029  */
00030 
00031 #ifndef _HASHTABLE_POLICY_H
00032 #define _HASHTABLE_POLICY_H 1
00033 
00034 namespace std _GLIBCXX_VISIBILITY(default)
00035 {
00036 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00037 
00038   template<typename _Key, typename _Value, typename _Alloc,
00039        typename _ExtractKey, typename _Equal,
00040        typename _H1, typename _H2, typename _Hash,
00041        typename _RehashPolicy, typename _Traits>
00042     class _Hashtable;
00043 
00044 _GLIBCXX_END_NAMESPACE_VERSION
00045 
00046 namespace __detail
00047 {
00048 _GLIBCXX_BEGIN_NAMESPACE_VERSION
00049 
00050   /**
00051    *  @defgroup hashtable-detail Base and Implementation Classes
00052    *  @ingroup unordered_associative_containers
00053    *  @{
00054    */
00055   template<typename _Key, typename _Value,
00056        typename _ExtractKey, typename _Equal,
00057        typename _H1, typename _H2, typename _Hash, typename _Traits>
00058     struct _Hashtable_base;
00059 
00060   // Helper function: return distance(first, last) for forward
00061   // iterators, or 0 for input iterators.
00062   template<class _Iterator>
00063     inline typename std::iterator_traits<_Iterator>::difference_type
00064     __distance_fw(_Iterator __first, _Iterator __last,
00065           std::input_iterator_tag)
00066     { return 0; }
00067 
00068   template<class _Iterator>
00069     inline typename std::iterator_traits<_Iterator>::difference_type
00070     __distance_fw(_Iterator __first, _Iterator __last,
00071           std::forward_iterator_tag)
00072     { return std::distance(__first, __last); }
00073 
00074   template<class _Iterator>
00075     inline typename std::iterator_traits<_Iterator>::difference_type
00076     __distance_fw(_Iterator __first, _Iterator __last)
00077     {
00078       typedef typename std::iterator_traits<_Iterator>::iterator_category _Tag;
00079       return __distance_fw(__first, __last, _Tag());
00080     }
00081 
00082   // Helper type used to detect whether the hash functor is noexcept.
00083   template <typename _Key, typename _Hash>
00084     struct __is_noexcept_hash : std::integral_constant<bool,
00085     noexcept(declval<const _Hash&>()(declval<const _Key&>()))>
00086     { };
00087 
00088   struct _Identity
00089   {
00090     template<typename _Tp>
00091       _Tp&&
00092       operator()(_Tp&& __x) const
00093       { return std::forward<_Tp>(__x); }
00094   };
00095 
00096   struct _Select1st
00097   {
00098     template<typename _Tp>
00099       auto
00100       operator()(_Tp&& __x) const
00101       -> decltype(std::get<0>(std::forward<_Tp>(__x)))
00102       { return std::get<0>(std::forward<_Tp>(__x)); }
00103   };
00104 
00105   // Auxiliary types used for all instantiations of _Hashtable nodes
00106   // and iterators.
00107 
00108   /**
00109    *  struct _Hashtable_traits
00110    *
00111    *  Important traits for hash tables.
00112    *
00113    *  @tparam _Cache_hash_code  Boolean value. True if the value of
00114    *  the hash function is stored along with the value. This is a
00115    *  time-space tradeoff.  Storing it may improve lookup speed by
00116    *  reducing the number of times we need to call the _Equal
00117    *  function.
00118    *
00119    *  @tparam _Constant_iterators  Boolean value. True if iterator and
00120    *  const_iterator are both constant iterator types. This is true
00121    *  for unordered_set and unordered_multiset, false for
00122    *  unordered_map and unordered_multimap.
00123    *
00124    *  @tparam _Unique_keys  Boolean value. True if the return value
00125    *  of _Hashtable::count(k) is always at most one, false if it may
00126    *  be an arbitrary number. This is true for unordered_set and
00127    *  unordered_map, false for unordered_multiset and
00128    *  unordered_multimap.
00129    */
00130   template<bool _Cache_hash_code, bool _Constant_iterators, bool _Unique_keys>
00131     struct _Hashtable_traits
00132     {
00133       template<bool _Cond>
00134     using __bool_constant = integral_constant<bool, _Cond>;
00135 
00136       using __hash_cached = __bool_constant<_Cache_hash_code>;
00137       using __constant_iterators = __bool_constant<_Constant_iterators>;
00138       using __unique_keys = __bool_constant<_Unique_keys>;
00139     };
00140 
00141   /**
00142    *  struct _Hash_node_base
00143    *
00144    *  Nodes, used to wrap elements stored in the hash table.  A policy
00145    *  template parameter of class template _Hashtable controls whether
00146    *  nodes also store a hash code. In some cases (e.g. strings) this
00147    *  may be a performance win.
00148    */
00149   struct _Hash_node_base
00150   {
00151     _Hash_node_base* _M_nxt;
00152 
00153     _Hash_node_base() : _M_nxt() { }
00154 
00155     _Hash_node_base(_Hash_node_base* __next) : _M_nxt(__next) { }
00156   };
00157 
00158   /**
00159    *  Primary template struct _Hash_node.
00160    */
00161   template<typename _Value, bool _Cache_hash_code>
00162     struct _Hash_node;
00163 
00164   /**
00165    *  Specialization for nodes with caches, struct _Hash_node.
00166    *
00167    *  Base class is __detail::_Hash_node_base.
00168    */
00169   template<typename _Value>
00170     struct _Hash_node<_Value, true> : _Hash_node_base
00171     {
00172       _Value       _M_v;
00173       std::size_t  _M_hash_code;
00174 
00175       template<typename... _Args>
00176     _Hash_node(_Args&&... __args)
00177     : _M_v(std::forward<_Args>(__args)...), _M_hash_code() { }
00178 
00179       _Hash_node*
00180       _M_next() const { return static_cast<_Hash_node*>(_M_nxt); }
00181     };
00182 
00183   /**
00184    *  Specialization for nodes without caches, struct _Hash_node.
00185    *
00186    *  Base class is __detail::_Hash_node_base.
00187    */
00188   template<typename _Value>
00189     struct _Hash_node<_Value, false> : _Hash_node_base
00190     {
00191       _Value       _M_v;
00192 
00193       template<typename... _Args>
00194     _Hash_node(_Args&&... __args)
00195     : _M_v(std::forward<_Args>(__args)...) { }
00196 
00197       _Hash_node*
00198       _M_next() const { return static_cast<_Hash_node*>(_M_nxt); }
00199     };
00200 
00201   /// Base class for node iterators.
00202   template<typename _Value, bool _Cache_hash_code>
00203     struct _Node_iterator_base
00204     {
00205       using __node_type = _Hash_node<_Value, _Cache_hash_code>;
00206 
00207       __node_type*  _M_cur;
00208 
00209       _Node_iterator_base(__node_type* __p)
00210       : _M_cur(__p) { }
00211 
00212       void
00213       _M_incr()
00214       { _M_cur = _M_cur->_M_next(); }
00215     };
00216 
00217   template<typename _Value, bool _Cache_hash_code>
00218     inline bool
00219     operator==(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
00220            const _Node_iterator_base<_Value, _Cache_hash_code >& __y)
00221     { return __x._M_cur == __y._M_cur; }
00222 
00223   template<typename _Value, bool _Cache_hash_code>
00224     inline bool
00225     operator!=(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
00226            const _Node_iterator_base<_Value, _Cache_hash_code>& __y)
00227     { return __x._M_cur != __y._M_cur; }
00228 
00229   /// Node iterators, used to iterate through all the hashtable.
00230   template<typename _Value, bool __constant_iterators, bool __cache>
00231     struct _Node_iterator
00232     : public _Node_iterator_base<_Value, __cache>
00233     {
00234     private:
00235       using __base_type = _Node_iterator_base<_Value, __cache>;
00236       using __node_type = typename __base_type::__node_type;
00237 
00238     public:
00239       typedef _Value                                   value_type;
00240       typedef std::ptrdiff_t                           difference_type;
00241       typedef std::forward_iterator_tag                iterator_category;
00242 
00243       using pointer = typename std::conditional<__constant_iterators,
00244                         const _Value*, _Value*>::type;
00245 
00246       using reference = typename std::conditional<__constant_iterators,
00247                           const _Value&, _Value&>::type;
00248 
00249       _Node_iterator()
00250       : __base_type(0) { }
00251 
00252       explicit
00253       _Node_iterator(__node_type* __p)
00254       : __base_type(__p) { }
00255 
00256       reference
00257       operator*() const
00258       { return this->_M_cur->_M_v; }
00259 
00260       pointer
00261       operator->() const
00262       { return std::__addressof(this->_M_cur->_M_v); }
00263 
00264       _Node_iterator&
00265       operator++()
00266       {
00267     this->_M_incr();
00268     return *this;
00269       }
00270 
00271       _Node_iterator
00272       operator++(int)
00273       {
00274     _Node_iterator __tmp(*this);
00275     this->_M_incr();
00276     return __tmp;
00277       }
00278     };
00279 
00280   /// Node const_iterators, used to iterate through all the hashtable.
00281   template<typename _Value, bool __constant_iterators, bool __cache>
00282     struct _Node_const_iterator
00283     : public _Node_iterator_base<_Value, __cache>
00284     {
00285     private:
00286       using __base_type = _Node_iterator_base<_Value, __cache>;
00287       using __node_type = typename __base_type::__node_type;
00288 
00289     public:
00290       typedef _Value                                   value_type;
00291       typedef std::ptrdiff_t                           difference_type;
00292       typedef std::forward_iterator_tag                iterator_category;
00293 
00294       typedef const _Value*                            pointer;
00295       typedef const _Value&                            reference;
00296 
00297       _Node_const_iterator()
00298       : __base_type(0) { }
00299 
00300       explicit
00301       _Node_const_iterator(__node_type* __p)
00302       : __base_type(__p) { }
00303 
00304       _Node_const_iterator(const _Node_iterator<_Value, __constant_iterators,
00305                __cache>& __x)
00306       : __base_type(__x._M_cur) { }
00307 
00308       reference
00309       operator*() const
00310       { return this->_M_cur->_M_v; }
00311 
00312       pointer
00313       operator->() const
00314       { return std::__addressof(this->_M_cur->_M_v); }
00315 
00316       _Node_const_iterator&
00317       operator++()
00318       {
00319     this->_M_incr();
00320     return *this;
00321       }
00322 
00323       _Node_const_iterator
00324       operator++(int)
00325       {
00326     _Node_const_iterator __tmp(*this);
00327     this->_M_incr();
00328     return __tmp;
00329       }
00330     };
00331 
00332   // Many of class template _Hashtable's template parameters are policy
00333   // classes.  These are defaults for the policies.
00334 
00335   /// Default range hashing function: use division to fold a large number
00336   /// into the range [0, N).
00337   struct _Mod_range_hashing
00338   {
00339     typedef std::size_t first_argument_type;
00340     typedef std::size_t second_argument_type;
00341     typedef std::size_t result_type;
00342 
00343     result_type
00344     operator()(first_argument_type __num, second_argument_type __den) const
00345     { return __num % __den; }
00346   };
00347 
00348   /// Default ranged hash function H.  In principle it should be a
00349   /// function object composed from objects of type H1 and H2 such that
00350   /// h(k, N) = h2(h1(k), N), but that would mean making extra copies of
00351   /// h1 and h2.  So instead we'll just use a tag to tell class template
00352   /// hashtable to do that composition.
00353   struct _Default_ranged_hash { };
00354 
00355   /// Default value for rehash policy.  Bucket size is (usually) the
00356   /// smallest prime that keeps the load factor small enough.
00357   struct _Prime_rehash_policy
00358   {
00359     _Prime_rehash_policy(float __z = 1.0)
00360     : _M_max_load_factor(__z), _M_next_resize(0) { }
00361 
00362     float
00363     max_load_factor() const noexcept
00364     { return _M_max_load_factor; }
00365 
00366     // Return a bucket size no smaller than n.
00367     std::size_t
00368     _M_next_bkt(std::size_t __n) const;
00369 
00370     // Return a bucket count appropriate for n elements
00371     std::size_t
00372     _M_bkt_for_elements(std::size_t __n) const
00373     { return __builtin_ceil(__n / (long double)_M_max_load_factor); }
00374 
00375     // __n_bkt is current bucket count, __n_elt is current element count,
00376     // and __n_ins is number of elements to be inserted.  Do we need to
00377     // increase bucket count?  If so, return make_pair(true, n), where n
00378     // is the new bucket count.  If not, return make_pair(false, 0).
00379     std::pair<bool, std::size_t>
00380     _M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
00381            std::size_t __n_ins) const;
00382 
00383     typedef std::size_t _State;
00384 
00385     _State
00386     _M_state() const
00387     { return _M_next_resize; }
00388 
00389     void
00390     _M_reset(_State __state)
00391     { _M_next_resize = __state; }
00392 
00393     enum { _S_n_primes = sizeof(unsigned long) != 8 ? 256 : 256 + 48 };
00394 
00395     static const std::size_t _S_growth_factor = 2;
00396 
00397     float                _M_max_load_factor;
00398     mutable std::size_t  _M_next_resize;
00399   };
00400 
00401   // Base classes for std::_Hashtable.  We define these base classes
00402   // because in some cases we want to do different things depending on
00403   // the value of a policy class.  In some cases the policy class
00404   // affects which member functions and nested typedefs are defined;
00405   // we handle that by specializing base class templates.  Several of
00406   // the base class templates need to access other members of class
00407   // template _Hashtable, so we use a variant of the "Curiously
00408   // Recurring Template Pattern" (CRTP) technique.
00409 
00410   /**
00411    *  Primary class template _Map_base.
00412    *
00413    *  If the hashtable has a value type of the form pair<T1, T2> and a
00414    *  key extraction policy (_ExtractKey) that returns the first part
00415    *  of the pair, the hashtable gets a mapped_type typedef.  If it
00416    *  satisfies those criteria and also has unique keys, then it also
00417    *  gets an operator[].
00418    */
00419   template<typename _Key, typename _Value, typename _Alloc,
00420        typename _ExtractKey, typename _Equal,
00421        typename _H1, typename _H2, typename _Hash,
00422        typename _RehashPolicy, typename _Traits,
00423        bool _Unique_keys = _Traits::__unique_keys::value>
00424     struct _Map_base { };
00425 
00426   /// Partial specialization, __unique_keys set to false.
00427   template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
00428        typename _H1, typename _H2, typename _Hash,
00429        typename _RehashPolicy, typename _Traits>
00430     struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00431              _H1, _H2, _Hash, _RehashPolicy, _Traits, false>
00432     {
00433       using mapped_type = typename std::tuple_element<1, _Pair>::type;
00434     };
00435 
00436   /// Partial specialization, __unique_keys set to true.
00437   template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
00438        typename _H1, typename _H2, typename _Hash,
00439        typename _RehashPolicy, typename _Traits>
00440     struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00441              _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
00442     {
00443     private:
00444       using __hashtable_base = __detail::_Hashtable_base<_Key, _Pair,
00445                              _Select1st,
00446                             _Equal, _H1, _H2, _Hash,
00447                               _Traits>;
00448 
00449       using __hashtable = _Hashtable<_Key, _Pair, _Alloc,
00450                      _Select1st, _Equal,
00451                      _H1, _H2, _Hash, _RehashPolicy, _Traits>;
00452 
00453       using __hash_code = typename __hashtable_base::__hash_code;
00454       using __node_type = typename __hashtable_base::__node_type;
00455 
00456     public:
00457       using key_type = typename __hashtable_base::key_type;
00458       using iterator = typename __hashtable_base::iterator;
00459       using mapped_type = typename std::tuple_element<1, _Pair>::type;
00460 
00461       mapped_type&
00462       operator[](const key_type& __k);
00463 
00464       mapped_type&
00465       operator[](key_type&& __k);
00466 
00467       // _GLIBCXX_RESOLVE_LIB_DEFECTS
00468       // DR 761. unordered_map needs an at() member function.
00469       mapped_type&
00470       at(const key_type& __k);
00471 
00472       const mapped_type&
00473       at(const key_type& __k) const;
00474     };
00475 
00476   template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
00477        typename _H1, typename _H2, typename _Hash,
00478        typename _RehashPolicy, typename _Traits>
00479     typename _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00480                _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
00481                ::mapped_type&
00482     _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00483           _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
00484     operator[](const key_type& __k)
00485     {
00486       __hashtable* __h = static_cast<__hashtable*>(this);
00487       __hash_code __code = __h->_M_hash_code(__k);
00488       std::size_t __n = __h->_M_bucket_index(__k, __code);
00489       __node_type* __p = __h->_M_find_node(__n, __k, __code);
00490 
00491       if (!__p)
00492     {
00493       __p = __h->_M_allocate_node(std::piecewise_construct,
00494                       std::tuple<const key_type&>(__k),
00495                       std::tuple<>());
00496       return __h->_M_insert_unique_node(__n, __code, __p)->second;
00497     }
00498 
00499       return (__p->_M_v).second;
00500     }
00501 
00502   template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
00503        typename _H1, typename _H2, typename _Hash,
00504        typename _RehashPolicy, typename _Traits>
00505     typename _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00506                _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
00507                ::mapped_type&
00508     _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00509           _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
00510     operator[](key_type&& __k)
00511     {
00512       __hashtable* __h = static_cast<__hashtable*>(this);
00513       __hash_code __code = __h->_M_hash_code(__k);
00514       std::size_t __n = __h->_M_bucket_index(__k, __code);
00515       __node_type* __p = __h->_M_find_node(__n, __k, __code);
00516 
00517       if (!__p)
00518     {
00519       __p = __h->_M_allocate_node(std::piecewise_construct,
00520                       std::forward_as_tuple(std::move(__k)),
00521                       std::tuple<>());
00522       return __h->_M_insert_unique_node(__n, __code, __p)->second;
00523     }
00524 
00525       return (__p->_M_v).second;
00526     }
00527 
00528   template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
00529        typename _H1, typename _H2, typename _Hash,
00530        typename _RehashPolicy, typename _Traits>
00531     typename _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00532                _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
00533                ::mapped_type&
00534     _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00535           _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
00536     at(const key_type& __k)
00537     {
00538       __hashtable* __h = static_cast<__hashtable*>(this);
00539       __hash_code __code = __h->_M_hash_code(__k);
00540       std::size_t __n = __h->_M_bucket_index(__k, __code);
00541       __node_type* __p = __h->_M_find_node(__n, __k, __code);
00542 
00543       if (!__p)
00544     __throw_out_of_range(__N("_Map_base::at"));
00545       return (__p->_M_v).second;
00546     }
00547 
00548   template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
00549        typename _H1, typename _H2, typename _Hash,
00550        typename _RehashPolicy, typename _Traits>
00551     const typename _Map_base<_Key, _Pair, _Alloc, _Select1st,
00552                  _Equal, _H1, _H2, _Hash, _RehashPolicy,
00553                  _Traits, true>::mapped_type&
00554     _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
00555           _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
00556     at(const key_type& __k) const
00557     {
00558       const __hashtable* __h = static_cast<const __hashtable*>(this);
00559       __hash_code __code = __h->_M_hash_code(__k);
00560       std::size_t __n = __h->_M_bucket_index(__k, __code);
00561       __node_type* __p = __h->_M_find_node(__n, __k, __code);
00562 
00563       if (!__p)
00564     __throw_out_of_range(__N("_Map_base::at"));
00565       return (__p->_M_v).second;
00566     }
00567 
00568   /**
00569    *  Primary class template _Insert_base.
00570    *
00571    *  insert member functions appropriate to all _Hashtables.
00572    */
00573   template<typename _Key, typename _Value, typename _Alloc,
00574        typename _ExtractKey, typename _Equal,
00575        typename _H1, typename _H2, typename _Hash,
00576        typename _RehashPolicy, typename _Traits>
00577     struct _Insert_base
00578     {
00579       using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
00580                      _Equal, _H1, _H2, _Hash,
00581                      _RehashPolicy, _Traits>;
00582 
00583       using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey,
00584                            _Equal, _H1, _H2, _Hash,
00585                            _Traits>;
00586 
00587       using value_type = typename __hashtable_base::value_type;
00588       using iterator = typename __hashtable_base::iterator;
00589       using const_iterator =  typename __hashtable_base::const_iterator;
00590       using size_type = typename __hashtable_base::size_type;
00591 
00592       using __unique_keys = typename __hashtable_base::__unique_keys;
00593       using __ireturn_type = typename __hashtable_base::__ireturn_type;
00594       using __iconv_type = typename __hashtable_base::__iconv_type;
00595 
00596       __hashtable&
00597       _M_conjure_hashtable()
00598       { return *(static_cast<__hashtable*>(this)); }
00599 
00600       __ireturn_type
00601       insert(const value_type& __v)
00602       {
00603     __hashtable& __h = _M_conjure_hashtable();
00604     return __h._M_insert(__v, __unique_keys());
00605       }
00606 
00607       iterator
00608       insert(const_iterator, const value_type& __v)
00609       { return __iconv_type()(insert(__v)); }
00610 
00611       void
00612       insert(initializer_list<value_type> __l)
00613       { this->insert(__l.begin(), __l.end()); }
00614 
00615       template<typename _InputIterator>
00616     void
00617     insert(_InputIterator __first, _InputIterator __last);
00618     };
00619 
00620   template<typename _Key, typename _Value, typename _Alloc,
00621        typename _ExtractKey, typename _Equal,
00622        typename _H1, typename _H2, typename _Hash,
00623        typename _RehashPolicy, typename _Traits>
00624     template<typename _InputIterator>
00625       void
00626       _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
00627             _RehashPolicy, _Traits>::
00628       insert(_InputIterator __first, _InputIterator __last)
00629       {
00630     using __rehash_type = typename __hashtable::__rehash_type;
00631     using __rehash_state = typename __hashtable::__rehash_state;
00632     using pair_type = std::pair<bool, std::size_t>;
00633 
00634     size_type __n_elt = __detail::__distance_fw(__first, __last);
00635 
00636     __hashtable& __h = _M_conjure_hashtable();
00637     __rehash_type& __rehash = __h._M_rehash_policy;
00638     const __rehash_state& __saved_state = __rehash._M_state();
00639     pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count,
00640                             __h._M_element_count,
00641                             __n_elt);
00642 
00643     if (__do_rehash.first)
00644       __h._M_rehash(__do_rehash.second, __saved_state);
00645 
00646     for (; __first != __last; ++__first)
00647       __h._M_insert(*__first, __unique_keys());
00648       }
00649 
00650   /**
00651    *  Primary class template _Insert.
00652    *
00653    *  Select insert member functions appropriate to _Hashtable policy choices.
00654    */
00655   template<typename _Key, typename _Value, typename _Alloc,
00656        typename _ExtractKey, typename _Equal,
00657        typename _H1, typename _H2, typename _Hash,
00658        typename _RehashPolicy, typename _Traits,
00659        bool _Constant_iterators = _Traits::__constant_iterators::value,
00660        bool _Unique_keys = _Traits::__unique_keys::value>
00661     struct _Insert;
00662 
00663   /// Specialization.
00664   template<typename _Key, typename _Value, typename _Alloc,
00665        typename _ExtractKey, typename _Equal,
00666        typename _H1, typename _H2, typename _Hash,
00667        typename _RehashPolicy, typename _Traits>
00668     struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
00669            _RehashPolicy, _Traits, true, true>
00670     : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
00671                _H1, _H2, _Hash, _RehashPolicy, _Traits>
00672     {
00673       using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
00674                     _Equal, _H1, _H2, _Hash,
00675                     _RehashPolicy, _Traits>;
00676       using value_type = typename __base_type::value_type;
00677       using iterator = typename __base_type::iterator;
00678       using const_iterator =  typename __base_type::const_iterator;
00679 
00680       using __unique_keys = typename __base_type::__unique_keys;
00681       using __hashtable = typename __base_type::__hashtable;
00682 
00683       using __base_type::insert;
00684 
00685       std::pair<iterator, bool>
00686       insert(value_type&& __v)
00687       {
00688     __hashtable& __h = this->_M_conjure_hashtable();
00689     return __h._M_insert(std::move(__v), __unique_keys());
00690       }
00691 
00692       iterator
00693       insert(const_iterator, value_type&& __v)
00694       { return insert(std::move(__v)).first; }
00695     };
00696 
00697   /// Specialization.
00698   template<typename _Key, typename _Value, typename _Alloc,
00699        typename _ExtractKey, typename _Equal,
00700        typename _H1, typename _H2, typename _Hash,
00701        typename _RehashPolicy, typename _Traits>
00702     struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
00703            _RehashPolicy, _Traits, true, false>
00704     : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
00705                _H1, _H2, _Hash, _RehashPolicy, _Traits>
00706     {
00707       using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
00708                     _Equal, _H1, _H2, _Hash,
00709                     _RehashPolicy, _Traits>;
00710       using value_type = typename __base_type::value_type;
00711       using iterator = typename __base_type::iterator;
00712       using const_iterator =  typename __base_type::const_iterator;
00713 
00714       using __unique_keys = typename __base_type::__unique_keys;
00715       using __hashtable = typename __base_type::__hashtable;
00716 
00717       using __base_type::insert;
00718 
00719       iterator
00720       insert(value_type&& __v)
00721       {
00722     __hashtable& __h = this->_M_conjure_hashtable();
00723     return __h._M_insert(std::move(__v), __unique_keys());
00724       }
00725 
00726       iterator
00727       insert(const_iterator, value_type&& __v)
00728       { return insert(std::move(__v)); }
00729      };
00730 
00731   /// Specialization.
00732   template<typename _Key, typename _Value, typename _Alloc,
00733        typename _ExtractKey, typename _Equal,
00734        typename _H1, typename _H2, typename _Hash,
00735        typename _RehashPolicy, typename _Traits, bool _Unique_keys>
00736     struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
00737            _RehashPolicy, _Traits, false, _Unique_keys>
00738     : public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
00739                _H1, _H2, _Hash, _RehashPolicy, _Traits>
00740     {
00741       using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
00742                        _Equal, _H1, _H2, _Hash,
00743                        _RehashPolicy, _Traits>;
00744       using value_type = typename __base_type::value_type;
00745       using iterator = typename __base_type::iterator;
00746       using const_iterator =  typename __base_type::const_iterator;
00747 
00748       using __unique_keys = typename __base_type::__unique_keys;
00749       using __hashtable = typename __base_type::__hashtable;
00750       using __ireturn_type = typename __base_type::__ireturn_type;
00751       using __iconv_type = typename __base_type::__iconv_type;
00752 
00753       using __base_type::insert;
00754 
00755       template<typename _Pair>
00756     using __is_cons = std::is_constructible<value_type, _Pair&&>;
00757 
00758       template<typename _Pair>
00759     using _IFcons = std::enable_if<__is_cons<_Pair>::value>;
00760 
00761       template<typename _Pair>
00762     using _IFconsp = typename _IFcons<_Pair>::type;
00763 
00764       template<typename _Pair, typename = _IFconsp<_Pair>>
00765     __ireturn_type
00766     insert(_Pair&& __v)
00767     {
00768       __hashtable& __h = this->_M_conjure_hashtable();
00769       return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v));
00770     }
00771 
00772       template<typename _Pair, typename = _IFconsp<_Pair>>
00773     iterator
00774     insert(const_iterator, _Pair&& __v)
00775     { return __iconv_type()(insert(std::forward<_Pair>(__v))); }
00776    };
00777 
00778   /**
00779    *  Primary class template  _Rehash_base.
00780    *
00781    *  Give hashtable the max_load_factor functions and reserve iff the
00782    *  rehash policy is _Prime_rehash_policy.
00783   */
00784   template<typename _Key, typename _Value, typename _Alloc,
00785        typename _ExtractKey, typename _Equal,
00786        typename _H1, typename _H2, typename _Hash,
00787        typename _RehashPolicy, typename _Traits>
00788     struct _Rehash_base;
00789 
00790   /// Specialization.
00791   template<typename _Key, typename _Value, typename _Alloc,
00792        typename _ExtractKey, typename _Equal,
00793        typename _H1, typename _H2, typename _Hash, typename _Traits>
00794     struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
00795             _H1, _H2, _Hash, _Prime_rehash_policy, _Traits>
00796     {
00797       using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
00798                      _Equal, _H1, _H2, _Hash,
00799                      _Prime_rehash_policy, _Traits>;
00800 
00801       float
00802       max_load_factor() const noexcept
00803       {
00804     const __hashtable* __this = static_cast<const __hashtable*>(this);
00805     return __this->__rehash_policy().max_load_factor();
00806       }
00807 
00808       void
00809       max_load_factor(float __z)
00810       {
00811     __hashtable* __this = static_cast<__hashtable*>(this);
00812     __this->__rehash_policy(_Prime_rehash_policy(__z));
00813       }
00814 
00815       void
00816       reserve(std::size_t __n)
00817       {
00818     __hashtable* __this = static_cast<__hashtable*>(this);
00819     __this->rehash(__builtin_ceil(__n / max_load_factor()));
00820       }
00821     };
00822 
00823   /**
00824    *  Primary class template _Hashtable_ebo_helper.
00825    *
00826    *  Helper class using EBO when it is not forbidden, type is not
00827    *  final, and when it worth it, type is empty.
00828    */
00829   template<int _Nm, typename _Tp,
00830        bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)>
00831     struct _Hashtable_ebo_helper;
00832 
00833   /// Specialization using EBO.
00834   template<int _Nm, typename _Tp>
00835     struct _Hashtable_ebo_helper<_Nm, _Tp, true>
00836     : private _Tp
00837     {
00838       _Hashtable_ebo_helper() = default;
00839 
00840       _Hashtable_ebo_helper(const _Tp& __tp) : _Tp(__tp)
00841       { }
00842 
00843       static const _Tp&
00844       _S_cget(const _Hashtable_ebo_helper& __eboh)
00845       { return static_cast<const _Tp&>(__eboh); }
00846 
00847       static _Tp&
00848       _S_get(_Hashtable_ebo_helper& __eboh)
00849       { return static_cast<_Tp&>(__eboh); }
00850     };
00851 
00852   /// Specialization not using EBO.
00853   template<int _Nm, typename _Tp>
00854     struct _Hashtable_ebo_helper<_Nm, _Tp, false>
00855     {
00856       _Hashtable_ebo_helper() = default;
00857 
00858       _Hashtable_ebo_helper(const _Tp& __tp) : _M_tp(__tp)
00859       { }
00860 
00861       static const _Tp&
00862       _S_cget(const _Hashtable_ebo_helper& __eboh)
00863       { return __eboh._M_tp; }
00864 
00865       static _Tp&
00866       _S_get(_Hashtable_ebo_helper& __eboh)
00867       { return __eboh._M_tp; }
00868 
00869     private:
00870       _Tp _M_tp;
00871     };
00872 
00873   /**
00874    *  Primary class template _Local_iterator_base.
00875    *
00876    *  Base class for local iterators, used to iterate within a bucket
00877    *  but not between buckets.
00878    */
00879   template<typename _Key, typename _Value, typename _ExtractKey,
00880        typename _H1, typename _H2, typename _Hash,
00881        bool __cache_hash_code>
00882     struct _Local_iterator_base;
00883 
00884   /**
00885    *  Primary class template _Hash_code_base.
00886    *
00887    *  Encapsulates two policy issues that aren't quite orthogonal.
00888    *   (1) the difference between using a ranged hash function and using
00889    *       the combination of a hash function and a range-hashing function.
00890    *       In the former case we don't have such things as hash codes, so
00891    *       we have a dummy type as placeholder.
00892    *   (2) Whether or not we cache hash codes.  Caching hash codes is
00893    *       meaningless if we have a ranged hash function.
00894    *
00895    *  We also put the key extraction objects here, for convenience.
00896    *  Each specialization derives from one or more of the template
00897    *  parameters to benefit from Ebo. This is important as this type
00898    *  is inherited in some cases by the _Local_iterator_base type used
00899    *  to implement local_iterator and const_local_iterator. As with
00900    *  any iterator type we prefer to make it as small as possible.
00901    *
00902    *  Primary template is unused except as a hook for specializations.
00903    */
00904   template<typename _Key, typename _Value, typename _ExtractKey,
00905        typename _H1, typename _H2, typename _Hash,
00906        bool __cache_hash_code>
00907     struct _Hash_code_base;
00908 
00909   /// Specialization: ranged hash function, no caching hash codes.  H1
00910   /// and H2 are provided but ignored.  We define a dummy hash code type.
00911   template<typename _Key, typename _Value, typename _ExtractKey,
00912        typename _H1, typename _H2, typename _Hash>
00913     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>
00914     : private _Hashtable_ebo_helper<0, _ExtractKey>,
00915       private _Hashtable_ebo_helper<1, _Hash>
00916     {
00917     private:
00918       using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
00919       using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>;
00920 
00921     protected:
00922       typedef void*                     __hash_code;
00923       typedef _Hash_node<_Value, false>         __node_type;
00924 
00925       // We need the default constructor for the local iterators.
00926       _Hash_code_base() = default;
00927 
00928       _Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&,
00929               const _Hash& __h)
00930       : __ebo_extract_key(__ex), __ebo_hash(__h) { }
00931 
00932       __hash_code
00933       _M_hash_code(const _Key& __key) const
00934       { return 0; }
00935 
00936       std::size_t
00937       _M_bucket_index(const _Key& __k, __hash_code, std::size_t __n) const
00938       { return _M_ranged_hash()(__k, __n); }
00939 
00940       std::size_t
00941       _M_bucket_index(const __node_type* __p, std::size_t __n) const
00942       { return _M_ranged_hash()(_M_extract()(__p->_M_v), __n); }
00943 
00944       void
00945       _M_store_code(__node_type*, __hash_code) const
00946       { }
00947 
00948       void
00949       _M_copy_code(__node_type*, const __node_type*) const
00950       { }
00951 
00952       void
00953       _M_swap(_Hash_code_base& __x)
00954       {
00955     std::swap(_M_extract(), __x._M_extract());
00956     std::swap(_M_ranged_hash(), __x._M_ranged_hash());
00957       }
00958 
00959       const _ExtractKey&
00960       _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
00961 
00962       _ExtractKey&
00963       _M_extract() { return __ebo_extract_key::_S_get(*this); }
00964 
00965       const _Hash&
00966       _M_ranged_hash() const { return __ebo_hash::_S_cget(*this); }
00967 
00968       _Hash&
00969       _M_ranged_hash() { return __ebo_hash::_S_get(*this); }
00970     };
00971 
00972   // No specialization for ranged hash function while caching hash codes.
00973   // That combination is meaningless, and trying to do it is an error.
00974 
00975   /// Specialization: ranged hash function, cache hash codes.  This
00976   /// combination is meaningless, so we provide only a declaration
00977   /// and no definition.
00978   template<typename _Key, typename _Value, typename _ExtractKey,
00979        typename _H1, typename _H2, typename _Hash>
00980     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>;
00981 
00982   /// Specialization: hash function and range-hashing function, no
00983   /// caching of hash codes.
00984   /// Provides typedef and accessor required by C++ 11.
00985   template<typename _Key, typename _Value, typename _ExtractKey,
00986        typename _H1, typename _H2>
00987     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
00988                _Default_ranged_hash, false>
00989     : private _Hashtable_ebo_helper<0, _ExtractKey>,
00990       private _Hashtable_ebo_helper<1, _H1>,
00991       private _Hashtable_ebo_helper<2, _H2>
00992     {
00993     private:
00994       using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
00995       using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
00996       using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
00997 
00998     public:
00999       typedef _H1                   hasher;
01000 
01001       hasher
01002       hash_function() const
01003       { return _M_h1(); }
01004 
01005     protected:
01006       typedef std::size_t               __hash_code;
01007       typedef _Hash_node<_Value, false>         __node_type;
01008 
01009       // We need the default constructor for the local iterators.
01010       _Hash_code_base() = default;
01011 
01012       _Hash_code_base(const _ExtractKey& __ex,
01013               const _H1& __h1, const _H2& __h2,
01014               const _Default_ranged_hash&)
01015       : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
01016 
01017       __hash_code
01018       _M_hash_code(const _Key& __k) const
01019       { return _M_h1()(__k); }
01020 
01021       std::size_t
01022       _M_bucket_index(const _Key&, __hash_code __c, std::size_t __n) const
01023       { return _M_h2()(__c, __n); }
01024 
01025       std::size_t
01026       _M_bucket_index(const __node_type* __p,
01027               std::size_t __n) const
01028       { return _M_h2()(_M_h1()(_M_extract()(__p->_M_v)), __n); }
01029 
01030       void
01031       _M_store_code(__node_type*, __hash_code) const
01032       { }
01033 
01034       void
01035       _M_copy_code(__node_type*, const __node_type*) const
01036       { }
01037 
01038       void
01039       _M_swap(_Hash_code_base& __x)
01040       {
01041     std::swap(_M_extract(), __x._M_extract());
01042     std::swap(_M_h1(), __x._M_h1());
01043     std::swap(_M_h2(), __x._M_h2());
01044       }
01045 
01046       const _ExtractKey&
01047       _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
01048 
01049       _ExtractKey&
01050       _M_extract() { return __ebo_extract_key::_S_get(*this); }
01051 
01052       const _H1&
01053       _M_h1() const { return __ebo_h1::_S_cget(*this); }
01054 
01055       _H1&
01056       _M_h1() { return __ebo_h1::_S_get(*this); }
01057 
01058       const _H2&
01059       _M_h2() const { return __ebo_h2::_S_cget(*this); }
01060 
01061       _H2&
01062       _M_h2() { return __ebo_h2::_S_get(*this); }
01063     };
01064 
01065   /// Specialization: hash function and range-hashing function,
01066   /// caching hash codes.  H is provided but ignored.  Provides
01067   /// typedef and accessor required by C++ 11.
01068   template<typename _Key, typename _Value, typename _ExtractKey,
01069        typename _H1, typename _H2>
01070     struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
01071                _Default_ranged_hash, true>
01072     : private _Hashtable_ebo_helper<0, _ExtractKey>,
01073       private _Hashtable_ebo_helper<1, _H1>,
01074       private _Hashtable_ebo_helper<2, _H2>
01075     {
01076     private:
01077       // Gives access to _M_h2() to the local iterator implementation.
01078       friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2,
01079                      _Default_ranged_hash, true>;
01080 
01081       using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
01082       using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
01083       using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
01084 
01085     public:
01086       typedef _H1                   hasher;
01087 
01088       hasher
01089       hash_function() const
01090       { return _M_h1(); }
01091 
01092     protected:
01093       typedef std::size_t               __hash_code;
01094       typedef _Hash_node<_Value, true>          __node_type;
01095 
01096       _Hash_code_base(const _ExtractKey& __ex,
01097               const _H1& __h1, const _H2& __h2,
01098               const _Default_ranged_hash&)
01099       : __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
01100 
01101       __hash_code
01102       _M_hash_code(const _Key& __k) const
01103       { return _M_h1()(__k); }
01104 
01105       std::size_t
01106       _M_bucket_index(const _Key&, __hash_code __c,
01107               std::size_t __n) const
01108       { return _M_h2()(__c, __n); }
01109 
01110       std::size_t
01111       _M_bucket_index(const __node_type* __p, std::size_t __n) const
01112       { return _M_h2()(__p->_M_hash_code, __n); }
01113 
01114       void
01115       _M_store_code(__node_type* __n, __hash_code __c) const
01116       { __n->_M_hash_code = __c; }
01117 
01118       void
01119       _M_copy_code(__node_type* __to, const __node_type* __from) const
01120       { __to->_M_hash_code = __from->_M_hash_code; }
01121 
01122       void
01123       _M_swap(_Hash_code_base& __x)
01124       {
01125     std::swap(_M_extract(), __x._M_extract());
01126     std::swap(_M_h1(), __x._M_h1());
01127     std::swap(_M_h2(), __x._M_h2());
01128       }
01129 
01130       const _ExtractKey&
01131       _M_extract() const { return __ebo_extract_key::_S_cget(*this); }
01132 
01133       _ExtractKey&
01134       _M_extract() { return __ebo_extract_key::_S_get(*this); }
01135 
01136       const _H1&
01137       _M_h1() const { return __ebo_h1::_S_cget(*this); }
01138 
01139       _H1&
01140       _M_h1() { return __ebo_h1::_S_get(*this); }
01141 
01142       const _H2&
01143       _M_h2() const { return __ebo_h2::_S_cget(*this); }
01144 
01145       _H2&
01146       _M_h2() { return __ebo_h2::_S_get(*this); }
01147     };
01148 
01149   /**
01150    *  Primary class template _Equal_helper.
01151    *
01152    */
01153   template <typename _Key, typename _Value, typename _ExtractKey,
01154         typename _Equal, typename _HashCodeType,
01155         bool __cache_hash_code>
01156   struct _Equal_helper;
01157 
01158   /// Specialization.
01159   template<typename _Key, typename _Value, typename _ExtractKey,
01160        typename _Equal, typename _HashCodeType>
01161   struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, true>
01162   {
01163     static bool
01164     _S_equals(const _Equal& __eq, const _ExtractKey& __extract,
01165           const _Key& __k, _HashCodeType __c, _Hash_node<_Value, true>* __n)
01166     { return __c == __n->_M_hash_code && __eq(__k, __extract(__n->_M_v)); }
01167   };
01168 
01169   /// Specialization.
01170   template<typename _Key, typename _Value, typename _ExtractKey,
01171        typename _Equal, typename _HashCodeType>
01172   struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, false>
01173   {
01174     static bool
01175     _S_equals(const _Equal& __eq, const _ExtractKey& __extract,
01176           const _Key& __k, _HashCodeType, _Hash_node<_Value, false>* __n)
01177     { return __eq(__k, __extract(__n->_M_v)); }
01178   };
01179 
01180 
01181   /// Specialization.
01182   template<typename _Key, typename _Value, typename _ExtractKey,
01183        typename _H1, typename _H2, typename _Hash>
01184     struct _Local_iterator_base<_Key, _Value, _ExtractKey,
01185                 _H1, _H2, _Hash, true>
01186     : private _Hashtable_ebo_helper<0, _H2>
01187     {
01188     protected:
01189       using __base_type = _Hashtable_ebo_helper<0, _H2>;
01190       using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
01191                            _H1, _H2, _Hash, true>;
01192 
01193     public:
01194       _Local_iterator_base() = default;
01195       _Local_iterator_base(const __hash_code_base& __base,
01196                _Hash_node<_Value, true>* __p,
01197                std::size_t __bkt, std::size_t __bkt_count)
01198       : __base_type(__base._M_h2()),
01199     _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
01200 
01201       void
01202       _M_incr()
01203       {
01204     _M_cur = _M_cur->_M_next();
01205     if (_M_cur)
01206       {
01207         std::size_t __bkt
01208           = __base_type::_S_get(*this)(_M_cur->_M_hash_code,
01209                        _M_bucket_count);
01210         if (__bkt != _M_bucket)
01211           _M_cur = nullptr;
01212       }
01213       }
01214 
01215       _Hash_node<_Value, true>*  _M_cur;
01216       std::size_t _M_bucket;
01217       std::size_t _M_bucket_count;
01218     };
01219 
01220   /// Specialization.
01221   template<typename _Key, typename _Value, typename _ExtractKey,
01222        typename _H1, typename _H2, typename _Hash>
01223     struct _Local_iterator_base<_Key, _Value, _ExtractKey,
01224                 _H1, _H2, _Hash, false>
01225     : private _Hash_code_base<_Key, _Value, _ExtractKey,
01226                   _H1, _H2, _Hash, false>
01227     {
01228     protected:
01229       using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
01230                            _H1, _H2, _Hash, false>;
01231 
01232     public:
01233       _Local_iterator_base() = default;
01234       _Local_iterator_base(const __hash_code_base& __base,
01235                _Hash_node<_Value, false>* __p,
01236                std::size_t __bkt, std::size_t __bkt_count)
01237     : __hash_code_base(__base),
01238       _M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
01239 
01240       void
01241       _M_incr()
01242       {
01243     _M_cur = _M_cur->_M_next();
01244     if (_M_cur)
01245       {
01246         std::size_t __bkt = this->_M_bucket_index(_M_cur, _M_bucket_count);
01247         if (__bkt != _M_bucket)
01248           _M_cur = nullptr;
01249       }
01250       }
01251 
01252       _Hash_node<_Value, false>*  _M_cur;
01253       std::size_t _M_bucket;
01254       std::size_t _M_bucket_count;
01255     };
01256 
01257   template<typename _Key, typename _Value, typename _ExtractKey,
01258        typename _H1, typename _H2, typename _Hash, bool __cache>
01259     inline bool
01260     operator==(const _Local_iterator_base<_Key, _Value, _ExtractKey,
01261                       _H1, _H2, _Hash, __cache>& __x,
01262            const _Local_iterator_base<_Key, _Value, _ExtractKey,
01263                       _H1, _H2, _Hash, __cache>& __y)
01264     { return __x._M_cur == __y._M_cur; }
01265 
01266   template<typename _Key, typename _Value, typename _ExtractKey,
01267        typename _H1, typename _H2, typename _Hash, bool __cache>
01268     inline bool
01269     operator!=(const _Local_iterator_base<_Key, _Value, _ExtractKey,
01270                       _H1, _H2, _Hash, __cache>& __x,
01271            const _Local_iterator_base<_Key, _Value, _ExtractKey,
01272                       _H1, _H2, _Hash, __cache>& __y)
01273     { return __x._M_cur != __y._M_cur; }
01274 
01275   /// local iterators
01276   template<typename _Key, typename _Value, typename _ExtractKey,
01277        typename _H1, typename _H2, typename _Hash,
01278        bool __constant_iterators, bool __cache>
01279     struct _Local_iterator
01280     : public _Local_iterator_base<_Key, _Value, _ExtractKey,
01281                   _H1, _H2, _Hash, __cache>
01282     {
01283     private:
01284       using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
01285                            _H1, _H2, _Hash, __cache>;
01286       using __hash_code_base = typename __base_type::__hash_code_base;
01287     public:
01288       typedef _Value                                   value_type;
01289       typedef typename std::conditional<__constant_iterators,
01290                     const _Value*, _Value*>::type
01291                                pointer;
01292       typedef typename std::conditional<__constant_iterators,
01293                     const _Value&, _Value&>::type
01294                                reference;
01295       typedef std::ptrdiff_t                           difference_type;
01296       typedef std::forward_iterator_tag                iterator_category;
01297 
01298       _Local_iterator() = default;
01299 
01300       _Local_iterator(const __hash_code_base& __base,
01301               _Hash_node<_Value, __cache>* __p,
01302               std::size_t __bkt, std::size_t __bkt_count)
01303     : __base_type(__base, __p, __bkt, __bkt_count)
01304       { }
01305 
01306       reference
01307       operator*() const
01308       { return this->_M_cur->_M_v; }
01309 
01310       pointer
01311       operator->() const
01312       { return std::__addressof(this->_M_cur->_M_v); }
01313 
01314       _Local_iterator&
01315       operator++()
01316       {
01317     this->_M_incr();
01318     return *this;
01319       }
01320 
01321       _Local_iterator
01322       operator++(int)
01323       {
01324     _Local_iterator __tmp(*this);
01325     this->_M_incr();
01326     return __tmp;
01327       }
01328     };
01329 
01330   /// local const_iterators
01331   template<typename _Key, typename _Value, typename _ExtractKey,
01332        typename _H1, typename _H2, typename _Hash,
01333        bool __constant_iterators, bool __cache>
01334     struct _Local_const_iterator
01335     : public _Local_iterator_base<_Key, _Value, _ExtractKey,
01336                   _H1, _H2, _Hash, __cache>
01337     {
01338     private:
01339       using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
01340                            _H1, _H2, _Hash, __cache>;
01341       using __hash_code_base = typename __base_type::__hash_code_base;
01342 
01343     public:
01344       typedef _Value                                   value_type;
01345       typedef const _Value*                            pointer;
01346       typedef const _Value&                            reference;
01347       typedef std::ptrdiff_t                           difference_type;
01348       typedef std::forward_iterator_tag                iterator_category;
01349 
01350       _Local_const_iterator() = default;
01351 
01352       _Local_const_iterator(const __hash_code_base& __base,
01353                 _Hash_node<_Value, __cache>* __p,
01354                 std::size_t __bkt, std::size_t __bkt_count)
01355     : __base_type(__base, __p, __bkt, __bkt_count)
01356       { }
01357 
01358       _Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey,
01359                           _H1, _H2, _Hash,
01360                           __constant_iterators,
01361                           __cache>& __x)
01362     : __base_type(__x)
01363       { }
01364 
01365       reference
01366       operator*() const
01367       { return this->_M_cur->_M_v; }
01368 
01369       pointer
01370       operator->() const
01371       { return std::__addressof(this->_M_cur->_M_v); }
01372 
01373       _Local_const_iterator&
01374       operator++()
01375       {
01376     this->_M_incr();
01377     return *this;
01378       }
01379 
01380       _Local_const_iterator
01381       operator++(int)
01382       {
01383     _Local_const_iterator __tmp(*this);
01384     this->_M_incr();
01385     return __tmp;
01386       }
01387     };
01388 
01389   /**
01390    *  Primary class template _Hashtable_base.
01391    *
01392    *  Helper class adding management of _Equal functor to
01393    *  _Hash_code_base type.
01394    *
01395    *  Base class templates are:
01396    *    - __detail::_Hash_code_base
01397    *    - __detail::_Hashtable_ebo_helper
01398    */
01399   template<typename _Key, typename _Value,
01400        typename _ExtractKey, typename _Equal,
01401        typename _H1, typename _H2, typename _Hash, typename _Traits>
01402   struct _Hashtable_base
01403   : public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
01404                _Traits::__hash_cached::value>,
01405     private _Hashtable_ebo_helper<0, _Equal>
01406   {
01407   public:
01408     typedef _Key                                    key_type;
01409     typedef _Value                                  value_type;
01410     typedef _Equal                                  key_equal;
01411     typedef std::size_t                             size_type;
01412     typedef std::ptrdiff_t                          difference_type;
01413 
01414     using __traits_type = _Traits;
01415     using __hash_cached = typename __traits_type::__hash_cached;
01416     using __constant_iterators = typename __traits_type::__constant_iterators;
01417     using __unique_keys = typename __traits_type::__unique_keys;
01418 
01419     using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
01420                          _H1, _H2, _Hash,
01421                          __hash_cached::value>;
01422 
01423     using __hash_code = typename __hash_code_base::__hash_code;
01424     using __node_type = typename __hash_code_base::__node_type;
01425 
01426     using iterator = __detail::_Node_iterator<value_type,
01427                           __constant_iterators::value,
01428                           __hash_cached::value>;
01429 
01430     using const_iterator = __detail::_Node_const_iterator<value_type,
01431                            __constant_iterators::value,
01432                            __hash_cached::value>;
01433 
01434     using local_iterator = __detail::_Local_iterator<key_type, value_type,
01435                           _ExtractKey, _H1, _H2, _Hash,
01436                           __constant_iterators::value,
01437                              __hash_cached::value>;
01438 
01439     using const_local_iterator = __detail::_Local_const_iterator<key_type,
01440                                  value_type,
01441                     _ExtractKey, _H1, _H2, _Hash,
01442                     __constant_iterators::value,
01443                     __hash_cached::value>;
01444 
01445     using __ireturn_type = typename std::conditional<__unique_keys::value,
01446                              std::pair<iterator, bool>,
01447                              iterator>::type;
01448 
01449     using __iconv_type = typename  std::conditional<__unique_keys::value,
01450                             _Select1st, _Identity
01451                             >::type;
01452   private:
01453     using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>;
01454     using _EqualHelper =  _Equal_helper<_Key, _Value, _ExtractKey, _Equal,
01455                     __hash_code, __hash_cached::value>;
01456 
01457   protected:
01458     using __node_base = __detail::_Hash_node_base;
01459     using __bucket_type = __node_base*;
01460 
01461     _Hashtable_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2,
01462             const _Hash& __hash, const _Equal& __eq)
01463     : __hash_code_base(__ex, __h1, __h2, __hash), _EqualEBO(__eq)
01464     { }
01465 
01466     bool
01467     _M_equals(const _Key& __k, __hash_code __c, __node_type* __n) const
01468     {
01469       return _EqualHelper::_S_equals(_M_eq(), this->_M_extract(),
01470                      __k, __c, __n);
01471     }
01472 
01473     void
01474     _M_swap(_Hashtable_base& __x)
01475     {
01476       __hash_code_base::_M_swap(__x);
01477       std::swap(_M_eq(), __x._M_eq());
01478     }
01479 
01480     const _Equal&
01481     _M_eq() const { return _EqualEBO::_S_cget(*this); }
01482 
01483     _Equal&
01484     _M_eq() { return _EqualEBO::_S_get(*this); }
01485   };
01486 
01487   /**
01488    *  struct _Equality_base.
01489    *
01490    *  Common types and functions for class _Equality.
01491    */
01492   struct _Equality_base
01493   {
01494   protected:
01495     template<typename _Uiterator>
01496       static bool
01497       _S_is_permutation(_Uiterator, _Uiterator, _Uiterator);
01498   };
01499 
01500   // See std::is_permutation in N3068.
01501   template<typename _Uiterator>
01502     bool
01503     _Equality_base::
01504     _S_is_permutation(_Uiterator __first1, _Uiterator __last1,
01505               _Uiterator __first2)
01506     {
01507       for (; __first1 != __last1; ++__first1, ++__first2)
01508     if (!(*__first1 == *__first2))
01509       break;
01510 
01511       if (__first1 == __last1)
01512     return true;
01513 
01514       _Uiterator __last2 = __first2;
01515       std::advance(__last2, std::distance(__first1, __last1));
01516 
01517       for (_Uiterator __it1 = __first1; __it1 != __last1; ++__it1)
01518     {
01519       _Uiterator __tmp =  __first1;
01520       while (__tmp != __it1 && !bool(*__tmp == *__it1))
01521         ++__tmp;
01522 
01523       // We've seen this one before.
01524       if (__tmp != __it1)
01525         continue;
01526 
01527       std::ptrdiff_t __n2 = 0;
01528       for (__tmp = __first2; __tmp != __last2; ++__tmp)
01529         if (*__tmp == *__it1)
01530           ++__n2;
01531 
01532       if (!__n2)
01533         return false;
01534 
01535       std::ptrdiff_t __n1 = 0;
01536       for (__tmp = __it1; __tmp != __last1; ++__tmp)
01537         if (*__tmp == *__it1)
01538           ++__n1;
01539 
01540       if (__n1 != __n2)
01541         return false;
01542     }
01543       return true;
01544     }
01545 
01546   /**
01547    *  Primary class template  _Equality.
01548    *
01549    *  This is for implementing equality comparison for unordered
01550    *  containers, per N3068, by John Lakos and Pablo Halpern.
01551    *  Algorithmically, we follow closely the reference implementations
01552    *  therein.
01553    */
01554   template<typename _Key, typename _Value, typename _Alloc,
01555        typename _ExtractKey, typename _Equal,
01556        typename _H1, typename _H2, typename _Hash,
01557        typename _RehashPolicy, typename _Traits,
01558        bool _Unique_keys = _Traits::__unique_keys::value>
01559     struct _Equality;
01560 
01561   /// Specialization.
01562   template<typename _Key, typename _Value, typename _Alloc,
01563        typename _ExtractKey, typename _Equal,
01564        typename _H1, typename _H2, typename _Hash,
01565        typename _RehashPolicy, typename _Traits>
01566     struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
01567              _H1, _H2, _Hash, _RehashPolicy, _Traits, true>
01568     {
01569       using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
01570                      _H1, _H2, _Hash, _RehashPolicy, _Traits>;
01571 
01572       bool
01573       _M_equal(const __hashtable&) const;
01574     };
01575 
01576   template<typename _Key, typename _Value, typename _Alloc,
01577        typename _ExtractKey, typename _Equal,
01578        typename _H1, typename _H2, typename _Hash,
01579        typename _RehashPolicy, typename _Traits>
01580     bool
01581     _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
01582           _H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
01583     _M_equal(const __hashtable& __other) const
01584     {
01585       const __hashtable* __this = static_cast<const __hashtable*>(this);
01586 
01587       if (__this->size() != __other.size())
01588     return false;
01589 
01590       for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx)
01591     {
01592       const auto __ity = __other.find(_ExtractKey()(*__itx));
01593       if (__ity == __other.end() || !bool(*__ity == *__itx))
01594         return false;
01595     }
01596       return true;
01597     }
01598 
01599   /// Specialization.
01600   template<typename _Key, typename _Value, typename _Alloc,
01601        typename _ExtractKey, typename _Equal,
01602        typename _H1, typename _H2, typename _Hash,
01603        typename _RehashPolicy, typename _Traits>
01604     struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
01605              _H1, _H2, _Hash, _RehashPolicy, _Traits, false>
01606     : public _Equality_base
01607     {
01608       using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
01609                      _H1, _H2, _Hash, _RehashPolicy, _Traits>;
01610 
01611       bool
01612       _M_equal(const __hashtable&) const;
01613     };
01614 
01615   template<typename _Key, typename _Value, typename _Alloc,
01616        typename _ExtractKey, typename _Equal,
01617        typename _H1, typename _H2, typename _Hash,
01618        typename _RehashPolicy, typename _Traits>
01619     bool
01620     _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
01621           _H1, _H2, _Hash, _RehashPolicy, _Traits, false>::
01622     _M_equal(const __hashtable& __other) const
01623     {
01624       const __hashtable* __this = static_cast<const __hashtable*>(this);
01625 
01626       if (__this->size() != __other.size())
01627     return false;
01628 
01629       for (auto __itx = __this->begin(); __itx != __this->end();)
01630     {
01631       const auto __xrange = __this->equal_range(_ExtractKey()(*__itx));
01632       const auto __yrange = __other.equal_range(_ExtractKey()(*__itx));
01633 
01634       if (std::distance(__xrange.first, __xrange.second)
01635           != std::distance(__yrange.first, __yrange.second))
01636         return false;
01637 
01638       if (!_S_is_permutation(__xrange.first, __xrange.second,
01639                  __yrange.first))
01640         return false;
01641 
01642       __itx = __xrange.second;
01643     }
01644       return true;
01645     }
01646 
01647   /**
01648    * This type is to combine a _Hash_node_base instance with an allocator
01649    * instance through inheritance to benefit from EBO when possible.
01650    */
01651   template<typename _NodeAlloc>
01652     struct _Before_begin : public _NodeAlloc
01653     {
01654       _Hash_node_base _M_node;
01655 
01656       _Before_begin(const _Before_begin&) = default;
01657       _Before_begin(_Before_begin&&) = default;
01658 
01659       template<typename _Alloc>
01660     _Before_begin(_Alloc&& __a)
01661       : _NodeAlloc(std::forward<_Alloc>(__a))
01662     { }
01663     };
01664 
01665  //@} hashtable-detail
01666 _GLIBCXX_END_NAMESPACE_VERSION
01667 } // namespace __detail
01668 } // namespace std
01669 
01670 #endif // _HASHTABLE_POLICY_H