hashtable_policy.h
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// Internal policy header for unordered_set and unordered_map -*- 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/hashtable_policy.h
* This is an internal header file, included by other library headers.
* Do not attempt to use it directly.
* @headername{unordered_map,unordered_set}
*/
#ifndef _HASHTABLE_POLICY_H
#define _HASHTABLE_POLICY_H 1
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
class _Hashtable;
_GLIBCXX_END_NAMESPACE_VERSION
namespace __detail
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
/**
* @defgroup hashtable-detail Base and Implementation Classes
* @ingroup unordered_associative_containers
* @{
*/
template<typename _Key, typename _Value,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash, typename _Traits>
struct _Hashtable_base;
// Helper function: return distance(first, last) for forward
// iterators, or 0 for input iterators.
template<class _Iterator>
inline typename std::iterator_traits<_Iterator>::difference_type
__distance_fw(_Iterator __first, _Iterator __last,
std::input_iterator_tag)
{ return 0; }
template<class _Iterator>
inline typename std::iterator_traits<_Iterator>::difference_type
__distance_fw(_Iterator __first, _Iterator __last,
std::forward_iterator_tag)
{ return std::distance(__first, __last); }
template<class _Iterator>
inline typename std::iterator_traits<_Iterator>::difference_type
__distance_fw(_Iterator __first, _Iterator __last)
{
typedef typename std::iterator_traits<_Iterator>::iterator_category _Tag;
return __distance_fw(__first, __last, _Tag());
}
// Helper type used to detect whether the hash functor is noexcept.
template <typename _Key, typename _Hash>
struct __is_noexcept_hash : std::integral_constant<bool,
noexcept(declval<const _Hash&>()(declval<const _Key&>()))>
{ };
struct _Identity
{
template<typename _Tp>
_Tp&&
operator()(_Tp&& __x) const
{ return std::forward<_Tp>(__x); }
};
struct _Select1st
{
template<typename _Tp>
auto
operator()(_Tp&& __x) const
-> decltype(std::get<0>(std::forward<_Tp>(__x)))
{ return std::get<0>(std::forward<_Tp>(__x)); }
};
// Auxiliary types used for all instantiations of _Hashtable nodes
// and iterators.
/**
* struct _Hashtable_traits
*
* Important traits for hash tables.
*
* @tparam _Cache_hash_code Boolean value. True if the value of
* the hash function is stored along with the value. This is a
* time-space tradeoff. Storing it may improve lookup speed by
* reducing the number of times we need to call the _Equal
* function.
*
* @tparam _Constant_iterators Boolean value. True if iterator and
* const_iterator are both constant iterator types. This is true
* for unordered_set and unordered_multiset, false for
* unordered_map and unordered_multimap.
*
* @tparam _Unique_keys Boolean value. True if the return value
* of _Hashtable::count(k) is always at most one, false if it may
* be an arbitrary number. This is true for unordered_set and
* unordered_map, false for unordered_multiset and
* unordered_multimap.
*/
template<bool _Cache_hash_code, bool _Constant_iterators, bool _Unique_keys>
struct _Hashtable_traits
{
template<bool _Cond>
using __bool_constant = integral_constant<bool, _Cond>;
using __hash_cached = __bool_constant<_Cache_hash_code>;
using __constant_iterators = __bool_constant<_Constant_iterators>;
using __unique_keys = __bool_constant<_Unique_keys>;
};
/**
* struct _Hash_node_base
*
* Nodes, used to wrap elements stored in the hash table. A policy
* template parameter of class template _Hashtable controls whether
* nodes also store a hash code. In some cases (e.g. strings) this
* may be a performance win.
*/
struct _Hash_node_base
{
_Hash_node_base* _M_nxt;
_Hash_node_base() : _M_nxt() { }
_Hash_node_base(_Hash_node_base* __next) : _M_nxt(__next) { }
};
/**
* Primary template struct _Hash_node.
*/
template<typename _Value, bool _Cache_hash_code>
struct _Hash_node;
/**
* Specialization for nodes with caches, struct _Hash_node.
*
* Base class is __detail::_Hash_node_base.
*/
template<typename _Value>
struct _Hash_node<_Value, true> : _Hash_node_base
{
_Value _M_v;
std::size_t _M_hash_code;
template<typename... _Args>
_Hash_node(_Args&&... __args)
: _M_v(std::forward<_Args>(__args)...), _M_hash_code() { }
_Hash_node*
_M_next() const { return static_cast<_Hash_node*>(_M_nxt); }
};
/**
* Specialization for nodes without caches, struct _Hash_node.
*
* Base class is __detail::_Hash_node_base.
*/
template<typename _Value>
struct _Hash_node<_Value, false> : _Hash_node_base
{
_Value _M_v;
template<typename... _Args>
_Hash_node(_Args&&... __args)
: _M_v(std::forward<_Args>(__args)...) { }
_Hash_node*
_M_next() const { return static_cast<_Hash_node*>(_M_nxt); }
};
/// Base class for node iterators.
template<typename _Value, bool _Cache_hash_code>
struct _Node_iterator_base
{
using __node_type = _Hash_node<_Value, _Cache_hash_code>;
__node_type* _M_cur;
_Node_iterator_base(__node_type* __p)
: _M_cur(__p) { }
void
_M_incr()
{ _M_cur = _M_cur->_M_next(); }
};
template<typename _Value, bool _Cache_hash_code>
inline bool
operator==(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
const _Node_iterator_base<_Value, _Cache_hash_code >& __y)
{ return __x._M_cur == __y._M_cur; }
template<typename _Value, bool _Cache_hash_code>
inline bool
operator!=(const _Node_iterator_base<_Value, _Cache_hash_code>& __x,
const _Node_iterator_base<_Value, _Cache_hash_code>& __y)
{ return __x._M_cur != __y._M_cur; }
/// Node iterators, used to iterate through all the hashtable.
template<typename _Value, bool __constant_iterators, bool __cache>
struct _Node_iterator
: public _Node_iterator_base<_Value, __cache>
{
private:
using __base_type = _Node_iterator_base<_Value, __cache>;
using __node_type = typename __base_type::__node_type;
public:
typedef _Value value_type;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
using pointer = typename std::conditional<__constant_iterators,
const _Value*, _Value*>::type;
using reference = typename std::conditional<__constant_iterators,
const _Value&, _Value&>::type;
_Node_iterator()
: __base_type(0) { }
explicit
_Node_iterator(__node_type* __p)
: __base_type(__p) { }
reference
operator*() const
{ return this->_M_cur->_M_v; }
pointer
operator->() const
{ return std::__addressof(this->_M_cur->_M_v); }
_Node_iterator&
operator++()
{
this->_M_incr();
return *this;
}
_Node_iterator
operator++(int)
{
_Node_iterator __tmp(*this);
this->_M_incr();
return __tmp;
}
};
/// Node const_iterators, used to iterate through all the hashtable.
template<typename _Value, bool __constant_iterators, bool __cache>
struct _Node_const_iterator
: public _Node_iterator_base<_Value, __cache>
{
private:
using __base_type = _Node_iterator_base<_Value, __cache>;
using __node_type = typename __base_type::__node_type;
public:
typedef _Value value_type;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
typedef const _Value* pointer;
typedef const _Value& reference;
_Node_const_iterator()
: __base_type(0) { }
explicit
_Node_const_iterator(__node_type* __p)
: __base_type(__p) { }
_Node_const_iterator(const _Node_iterator<_Value, __constant_iterators,
__cache>& __x)
: __base_type(__x._M_cur) { }
reference
operator*() const
{ return this->_M_cur->_M_v; }
pointer
operator->() const
{ return std::__addressof(this->_M_cur->_M_v); }
_Node_const_iterator&
operator++()
{
this->_M_incr();
return *this;
}
_Node_const_iterator
operator++(int)
{
_Node_const_iterator __tmp(*this);
this->_M_incr();
return __tmp;
}
};
// Many of class template _Hashtable's template parameters are policy
// classes. These are defaults for the policies.
/// Default range hashing function: use division to fold a large number
/// into the range [0, N).
struct _Mod_range_hashing
{
typedef std::size_t first_argument_type;
typedef std::size_t second_argument_type;
typedef std::size_t result_type;
result_type
operator()(first_argument_type __num, second_argument_type __den) const
{ return __num % __den; }
};
/// Default ranged hash function H. In principle it should be a
/// function object composed from objects of type H1 and H2 such that
/// h(k, N) = h2(h1(k), N), but that would mean making extra copies of
/// h1 and h2. So instead we'll just use a tag to tell class template
/// hashtable to do that composition.
struct _Default_ranged_hash { };
/// Default value for rehash policy. Bucket size is (usually) the
/// smallest prime that keeps the load factor small enough.
struct _Prime_rehash_policy
{
_Prime_rehash_policy(float __z = 1.0)
: _M_max_load_factor(__z), _M_next_resize(0) { }
float
max_load_factor() const noexcept
{ return _M_max_load_factor; }
// Return a bucket size no smaller than n.
std::size_t
_M_next_bkt(std::size_t __n) const;
// Return a bucket count appropriate for n elements
std::size_t
_M_bkt_for_elements(std::size_t __n) const
{ return __builtin_ceil(__n / (long double)_M_max_load_factor); }
// __n_bkt is current bucket count, __n_elt is current element count,
// and __n_ins is number of elements to be inserted. Do we need to
// increase bucket count? If so, return make_pair(true, n), where n
// is the new bucket count. If not, return make_pair(false, 0).
std::pair<bool, std::size_t>
_M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
std::size_t __n_ins) const;
typedef std::size_t _State;
_State
_M_state() const
{ return _M_next_resize; }
void
_M_reset(_State __state)
{ _M_next_resize = __state; }
enum { _S_n_primes = sizeof(unsigned long) != 8 ? 256 : 256 + 48 };
static const std::size_t _S_growth_factor = 2;
float _M_max_load_factor;
mutable std::size_t _M_next_resize;
};
// Base classes for std::_Hashtable. We define these base classes
// because in some cases we want to do different things depending on
// the value of a policy class. In some cases the policy class
// affects which member functions and nested typedefs are defined;
// we handle that by specializing base class templates. Several of
// the base class templates need to access other members of class
// template _Hashtable, so we use a variant of the "Curiously
// Recurring Template Pattern" (CRTP) technique.
/**
* Primary class template _Map_base.
*
* If the hashtable has a value type of the form pair<T1, T2> and a
* key extraction policy (_ExtractKey) that returns the first part
* of the pair, the hashtable gets a mapped_type typedef. If it
* satisfies those criteria and also has unique keys, then it also
* gets an operator[].
*/
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits,
bool _Unique_keys = _Traits::__unique_keys::value>
struct _Map_base { };
/// Partial specialization, __unique_keys set to false.
template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, false>
{
using mapped_type = typename std::tuple_element<1, _Pair>::type;
};
/// Partial specialization, __unique_keys set to true.
template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>
{
private:
using __hashtable_base = __detail::_Hashtable_base<_Key, _Pair,
_Select1st,
_Equal, _H1, _H2, _Hash,
_Traits>;
using __hashtable = _Hashtable<_Key, _Pair, _Alloc,
_Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits>;
using __hash_code = typename __hashtable_base::__hash_code;
using __node_type = typename __hashtable_base::__node_type;
public:
using key_type = typename __hashtable_base::key_type;
using iterator = typename __hashtable_base::iterator;
using mapped_type = typename std::tuple_element<1, _Pair>::type;
mapped_type&
operator[](const key_type& __k);
mapped_type&
operator[](key_type&& __k);
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 761. unordered_map needs an at() member function.
mapped_type&
at(const key_type& __k);
const mapped_type&
at(const key_type& __k) const;
};
template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
typename _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>
::mapped_type&
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
operator[](const key_type& __k)
{
__hashtable* __h = static_cast<__hashtable*>(this);
__hash_code __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
__node_type* __p = __h->_M_find_node(__n, __k, __code);
if (!__p)
{
__p = __h->_M_allocate_node(std::piecewise_construct,
std::tuple<const key_type&>(__k),
std::tuple<>());
return __h->_M_insert_unique_node(__n, __code, __p)->second;
}
return (__p->_M_v).second;
}
template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
typename _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>
::mapped_type&
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
operator[](key_type&& __k)
{
__hashtable* __h = static_cast<__hashtable*>(this);
__hash_code __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
__node_type* __p = __h->_M_find_node(__n, __k, __code);
if (!__p)
{
__p = __h->_M_allocate_node(std::piecewise_construct,
std::forward_as_tuple(std::move(__k)),
std::tuple<>());
return __h->_M_insert_unique_node(__n, __code, __p)->second;
}
return (__p->_M_v).second;
}
template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
typename _Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>
::mapped_type&
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
at(const key_type& __k)
{
__hashtable* __h = static_cast<__hashtable*>(this);
__hash_code __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
__node_type* __p = __h->_M_find_node(__n, __k, __code);
if (!__p)
__throw_out_of_range(__N("_Map_base::at"));
return (__p->_M_v).second;
}
template<typename _Key, typename _Pair, typename _Alloc, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
const typename _Map_base<_Key, _Pair, _Alloc, _Select1st,
_Equal, _H1, _H2, _Hash, _RehashPolicy,
_Traits, true>::mapped_type&
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
at(const key_type& __k) const
{
const __hashtable* __h = static_cast<const __hashtable*>(this);
__hash_code __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
__node_type* __p = __h->_M_find_node(__n, __k, __code);
if (!__p)
__throw_out_of_range(__N("_Map_base::at"));
return (__p->_M_v).second;
}
/**
* Primary class template _Insert_base.
*
* insert member functions appropriate to all _Hashtables.
*/
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Insert_base
{
using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>;
using __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_Traits>;
using value_type = typename __hashtable_base::value_type;
using iterator = typename __hashtable_base::iterator;
using const_iterator = typename __hashtable_base::const_iterator;
using size_type = typename __hashtable_base::size_type;
using __unique_keys = typename __hashtable_base::__unique_keys;
using __ireturn_type = typename __hashtable_base::__ireturn_type;
using __iconv_type = typename __hashtable_base::__iconv_type;
__hashtable&
_M_conjure_hashtable()
{ return *(static_cast<__hashtable*>(this)); }
__ireturn_type
insert(const value_type& __v)
{
__hashtable& __h = _M_conjure_hashtable();
return __h._M_insert(__v, __unique_keys());
}
iterator
insert(const_iterator, const value_type& __v)
{ return __iconv_type()(insert(__v)); }
void
insert(initializer_list<value_type> __l)
{ this->insert(__l.begin(), __l.end()); }
template<typename _InputIterator>
void
insert(_InputIterator __first, _InputIterator __last);
};
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
template<typename _InputIterator>
void
_Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>::
insert(_InputIterator __first, _InputIterator __last)
{
using __rehash_type = typename __hashtable::__rehash_type;
using __rehash_state = typename __hashtable::__rehash_state;
using pair_type = std::pair<bool, std::size_t>;
size_type __n_elt = __detail::__distance_fw(__first, __last);
__hashtable& __h = _M_conjure_hashtable();
__rehash_type& __rehash = __h._M_rehash_policy;
const __rehash_state& __saved_state = __rehash._M_state();
pair_type __do_rehash = __rehash._M_need_rehash(__h._M_bucket_count,
__h._M_element_count,
__n_elt);
if (__do_rehash.first)
__h._M_rehash(__do_rehash.second, __saved_state);
for (; __first != __last; ++__first)
this->insert(*__first);
}
/**
* Primary class template _Insert.
*
* Select insert member functions appropriate to _Hashtable policy choices.
*/
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits,
bool _Constant_iterators = _Traits::__constant_iterators::value,
bool _Unique_keys = _Traits::__unique_keys::value>
struct _Insert;
/// Specialization.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits, true, true>
: public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits>
{
using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>;
using value_type = typename __base_type::value_type;
using iterator = typename __base_type::iterator;
using const_iterator = typename __base_type::const_iterator;
using __unique_keys = typename __base_type::__unique_keys;
using __hashtable = typename __base_type::__hashtable;
using __base_type::insert;
std::pair<iterator, bool>
insert(value_type&& __v)
{
__hashtable& __h = this->_M_conjure_hashtable();
return __h._M_insert(std::move(__v), __unique_keys());
}
iterator
insert(const_iterator, value_type&& __v)
{ return insert(std::move(__v)).first; }
};
/// Specialization.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits, true, false>
: public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits>
{
using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>;
using value_type = typename __base_type::value_type;
using iterator = typename __base_type::iterator;
using const_iterator = typename __base_type::const_iterator;
using __unique_keys = typename __base_type::__unique_keys;
using __hashtable = typename __base_type::__hashtable;
using __base_type::insert;
iterator
insert(value_type&& __v)
{
__hashtable& __h = this->_M_conjure_hashtable();
return __h._M_insert(std::move(__v), __unique_keys());
}
iterator
insert(const_iterator, value_type&& __v)
{ return insert(std::move(__v)); }
};
/// Specialization.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits, bool _Unique_keys>
struct _Insert<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits, false, _Unique_keys>
: public _Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits>
{
using __base_type = _Insert_base<_Key, _Value, _Alloc, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>;
using value_type = typename __base_type::value_type;
using iterator = typename __base_type::iterator;
using const_iterator = typename __base_type::const_iterator;
using __unique_keys = typename __base_type::__unique_keys;
using __hashtable = typename __base_type::__hashtable;
using __ireturn_type = typename __base_type::__ireturn_type;
using __iconv_type = typename __base_type::__iconv_type;
using __base_type::insert;
template<typename _Pair>
using __is_cons = std::is_constructible<value_type, _Pair&&>;
template<typename _Pair>
using _IFcons = std::enable_if<__is_cons<_Pair>::value>;
template<typename _Pair>
using _IFconsp = typename _IFcons<_Pair>::type;
template<typename _Pair, typename = _IFconsp<_Pair>>
__ireturn_type
insert(_Pair&& __v)
{
__hashtable& __h = this->_M_conjure_hashtable();
return __h._M_emplace(__unique_keys(), std::forward<_Pair>(__v));
}
template<typename _Pair, typename = _IFconsp<_Pair>>
iterator
insert(const_iterator, _Pair&& __v)
{ return __iconv_type()(insert(std::forward<_Pair>(__v))); }
};
/**
* Primary class template _Rehash_base.
*
* Give hashtable the max_load_factor functions and reserve iff the
* rehash policy is _Prime_rehash_policy.
*/
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Rehash_base;
/// Specialization.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash, typename _Traits>
struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _Prime_rehash_policy, _Traits>
{
using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_Prime_rehash_policy, _Traits>;
float
max_load_factor() const noexcept
{
const __hashtable* __this = static_cast<const __hashtable*>(this);
return __this->__rehash_policy().max_load_factor();
}
void
max_load_factor(float __z)
{
__hashtable* __this = static_cast<__hashtable*>(this);
__this->__rehash_policy(_Prime_rehash_policy(__z));
}
void
reserve(std::size_t __n)
{
__hashtable* __this = static_cast<__hashtable*>(this);
__this->rehash(__builtin_ceil(__n / max_load_factor()));
}
};
/**
* Primary class template _Hashtable_ebo_helper.
*
* Helper class using EBO when it is not forbidden, type is not
* final, and when it worth it, type is empty.
*/
template<int _Nm, typename _Tp,
bool __use_ebo = !__is_final(_Tp) && __is_empty(_Tp)>
struct _Hashtable_ebo_helper;
/// Specialization using EBO.
template<int _Nm, typename _Tp>
struct _Hashtable_ebo_helper<_Nm, _Tp, true>
: private _Tp
{
_Hashtable_ebo_helper() = default;
_Hashtable_ebo_helper(const _Tp& __tp) : _Tp(__tp)
{ }
static const _Tp&
_S_cget(const _Hashtable_ebo_helper& __eboh)
{ return static_cast<const _Tp&>(__eboh); }
static _Tp&
_S_get(_Hashtable_ebo_helper& __eboh)
{ return static_cast<_Tp&>(__eboh); }
};
/// Specialization not using EBO.
template<int _Nm, typename _Tp>
struct _Hashtable_ebo_helper<_Nm, _Tp, false>
{
_Hashtable_ebo_helper() = default;
_Hashtable_ebo_helper(const _Tp& __tp) : _M_tp(__tp)
{ }
static const _Tp&
_S_cget(const _Hashtable_ebo_helper& __eboh)
{ return __eboh._M_tp; }
static _Tp&
_S_get(_Hashtable_ebo_helper& __eboh)
{ return __eboh._M_tp; }
private:
_Tp _M_tp;
};
/**
* Primary class template _Local_iterator_base.
*
* Base class for local iterators, used to iterate within a bucket
* but not between buckets.
*/
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash,
bool __cache_hash_code>
struct _Local_iterator_base;
/**
* Primary class template _Hash_code_base.
*
* Encapsulates two policy issues that aren't quite orthogonal.
* (1) the difference between using a ranged hash function and using
* the combination of a hash function and a range-hashing function.
* In the former case we don't have such things as hash codes, so
* we have a dummy type as placeholder.
* (2) Whether or not we cache hash codes. Caching hash codes is
* meaningless if we have a ranged hash function.
*
* We also put the key extraction objects here, for convenience.
* Each specialization derives from one or more of the template
* parameters to benefit from Ebo. This is important as this type
* is inherited in some cases by the _Local_iterator_base type used
* to implement local_iterator and const_local_iterator. As with
* any iterator type we prefer to make it as small as possible.
*
* Primary template is unused except as a hook for specializations.
*/
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash,
bool __cache_hash_code>
struct _Hash_code_base;
/// Specialization: ranged hash function, no caching hash codes. H1
/// and H2 are provided but ignored. We define a dummy hash code type.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash>
struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, false>
: private _Hashtable_ebo_helper<0, _ExtractKey>,
private _Hashtable_ebo_helper<1, _Hash>
{
private:
using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
using __ebo_hash = _Hashtable_ebo_helper<1, _Hash>;
protected:
typedef void* __hash_code;
typedef _Hash_node<_Value, false> __node_type;
// We need the default constructor for the local iterators.
_Hash_code_base() = default;
_Hash_code_base(const _ExtractKey& __ex, const _H1&, const _H2&,
const _Hash& __h)
: __ebo_extract_key(__ex), __ebo_hash(__h) { }
__hash_code
_M_hash_code(const _Key& __key) const
{ return 0; }
std::size_t
_M_bucket_index(const _Key& __k, __hash_code, std::size_t __n) const
{ return _M_ranged_hash()(__k, __n); }
std::size_t
_M_bucket_index(const __node_type* __p, std::size_t __n) const
{ return _M_ranged_hash()(_M_extract()(__p->_M_v), __n); }
void
_M_store_code(__node_type*, __hash_code) const
{ }
void
_M_copy_code(__node_type*, const __node_type*) const
{ }
void
_M_swap(_Hash_code_base& __x)
{
std::swap(_M_extract(), __x._M_extract());
std::swap(_M_ranged_hash(), __x._M_ranged_hash());
}
const _ExtractKey&
_M_extract() const { return __ebo_extract_key::_S_cget(*this); }
_ExtractKey&
_M_extract() { return __ebo_extract_key::_S_get(*this); }
const _Hash&
_M_ranged_hash() const { return __ebo_hash::_S_cget(*this); }
_Hash&
_M_ranged_hash() { return __ebo_hash::_S_get(*this); }
};
// No specialization for ranged hash function while caching hash codes.
// That combination is meaningless, and trying to do it is an error.
/// Specialization: ranged hash function, cache hash codes. This
/// combination is meaningless, so we provide only a declaration
/// and no definition.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash>
struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash, true>;
/// Specialization: hash function and range-hashing function, no
/// caching of hash codes.
/// Provides typedef and accessor required by C++ 11.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2>
struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
_Default_ranged_hash, false>
: private _Hashtable_ebo_helper<0, _ExtractKey>,
private _Hashtable_ebo_helper<1, _H1>,
private _Hashtable_ebo_helper<2, _H2>
{
private:
using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
public:
typedef _H1 hasher;
hasher
hash_function() const
{ return _M_h1(); }
protected:
typedef std::size_t __hash_code;
typedef _Hash_node<_Value, false> __node_type;
// We need the default constructor for the local iterators.
_Hash_code_base() = default;
_Hash_code_base(const _ExtractKey& __ex,
const _H1& __h1, const _H2& __h2,
const _Default_ranged_hash&)
: __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
__hash_code
_M_hash_code(const _Key& __k) const
{ return _M_h1()(__k); }
std::size_t
_M_bucket_index(const _Key&, __hash_code __c, std::size_t __n) const
{ return _M_h2()(__c, __n); }
std::size_t
_M_bucket_index(const __node_type* __p,
std::size_t __n) const
{ return _M_h2()(_M_h1()(_M_extract()(__p->_M_v)), __n); }
void
_M_store_code(__node_type*, __hash_code) const
{ }
void
_M_copy_code(__node_type*, const __node_type*) const
{ }
void
_M_swap(_Hash_code_base& __x)
{
std::swap(_M_extract(), __x._M_extract());
std::swap(_M_h1(), __x._M_h1());
std::swap(_M_h2(), __x._M_h2());
}
const _ExtractKey&
_M_extract() const { return __ebo_extract_key::_S_cget(*this); }
_ExtractKey&
_M_extract() { return __ebo_extract_key::_S_get(*this); }
const _H1&
_M_h1() const { return __ebo_h1::_S_cget(*this); }
_H1&
_M_h1() { return __ebo_h1::_S_get(*this); }
const _H2&
_M_h2() const { return __ebo_h2::_S_cget(*this); }
_H2&
_M_h2() { return __ebo_h2::_S_get(*this); }
};
/// Specialization: hash function and range-hashing function,
/// caching hash codes. H is provided but ignored. Provides
/// typedef and accessor required by C++ 11.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2>
struct _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2,
_Default_ranged_hash, true>
: private _Hashtable_ebo_helper<0, _ExtractKey>,
private _Hashtable_ebo_helper<1, _H1>,
private _Hashtable_ebo_helper<2, _H2>
{
private:
// Gives access to _M_h2() to the local iterator implementation.
friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2,
_Default_ranged_hash, true>;
using __ebo_extract_key = _Hashtable_ebo_helper<0, _ExtractKey>;
using __ebo_h1 = _Hashtable_ebo_helper<1, _H1>;
using __ebo_h2 = _Hashtable_ebo_helper<2, _H2>;
public:
typedef _H1 hasher;
hasher
hash_function() const
{ return _M_h1(); }
protected:
typedef std::size_t __hash_code;
typedef _Hash_node<_Value, true> __node_type;
_Hash_code_base(const _ExtractKey& __ex,
const _H1& __h1, const _H2& __h2,
const _Default_ranged_hash&)
: __ebo_extract_key(__ex), __ebo_h1(__h1), __ebo_h2(__h2) { }
__hash_code
_M_hash_code(const _Key& __k) const
{ return _M_h1()(__k); }
std::size_t
_M_bucket_index(const _Key&, __hash_code __c,
std::size_t __n) const
{ return _M_h2()(__c, __n); }
std::size_t
_M_bucket_index(const __node_type* __p, std::size_t __n) const
{ return _M_h2()(__p->_M_hash_code, __n); }
void
_M_store_code(__node_type* __n, __hash_code __c) const
{ __n->_M_hash_code = __c; }
void
_M_copy_code(__node_type* __to, const __node_type* __from) const
{ __to->_M_hash_code = __from->_M_hash_code; }
void
_M_swap(_Hash_code_base& __x)
{
std::swap(_M_extract(), __x._M_extract());
std::swap(_M_h1(), __x._M_h1());
std::swap(_M_h2(), __x._M_h2());
}
const _ExtractKey&
_M_extract() const { return __ebo_extract_key::_S_cget(*this); }
_ExtractKey&
_M_extract() { return __ebo_extract_key::_S_get(*this); }
const _H1&
_M_h1() const { return __ebo_h1::_S_cget(*this); }
_H1&
_M_h1() { return __ebo_h1::_S_get(*this); }
const _H2&
_M_h2() const { return __ebo_h2::_S_cget(*this); }
_H2&
_M_h2() { return __ebo_h2::_S_get(*this); }
};
/**
* Primary class template _Equal_helper.
*
*/
template <typename _Key, typename _Value, typename _ExtractKey,
typename _Equal, typename _HashCodeType,
bool __cache_hash_code>
struct _Equal_helper;
/// Specialization.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _Equal, typename _HashCodeType>
struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, true>
{
static bool
_S_equals(const _Equal& __eq, const _ExtractKey& __extract,
const _Key& __k, _HashCodeType __c, _Hash_node<_Value, true>* __n)
{ return __c == __n->_M_hash_code && __eq(__k, __extract(__n->_M_v)); }
};
/// Specialization.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _Equal, typename _HashCodeType>
struct _Equal_helper<_Key, _Value, _ExtractKey, _Equal, _HashCodeType, false>
{
static bool
_S_equals(const _Equal& __eq, const _ExtractKey& __extract,
const _Key& __k, _HashCodeType, _Hash_node<_Value, false>* __n)
{ return __eq(__k, __extract(__n->_M_v)); }
};
/// Specialization.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash>
struct _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, true>
: private _Hashtable_ebo_helper<0, _H2>
{
protected:
using __base_type = _Hashtable_ebo_helper<0, _H2>;
using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, true>;
public:
_Local_iterator_base() = default;
_Local_iterator_base(const __hash_code_base& __base,
_Hash_node<_Value, true>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: __base_type(__base._M_h2()),
_M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
void
_M_incr()
{
_M_cur = _M_cur->_M_next();
if (_M_cur)
{
std::size_t __bkt
= __base_type::_S_get(*this)(_M_cur->_M_hash_code,
_M_bucket_count);
if (__bkt != _M_bucket)
_M_cur = nullptr;
}
}
_Hash_node<_Value, true>* _M_cur;
std::size_t _M_bucket;
std::size_t _M_bucket_count;
};
/// Specialization.
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash>
struct _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>
: private _Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>
{
protected:
using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>;
public:
_Local_iterator_base() = default;
_Local_iterator_base(const __hash_code_base& __base,
_Hash_node<_Value, false>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: __hash_code_base(__base),
_M_cur(__p), _M_bucket(__bkt), _M_bucket_count(__bkt_count) { }
void
_M_incr()
{
_M_cur = _M_cur->_M_next();
if (_M_cur)
{
std::size_t __bkt = this->_M_bucket_index(_M_cur, _M_bucket_count);
if (__bkt != _M_bucket)
_M_cur = nullptr;
}
}
_Hash_node<_Value, false>* _M_cur;
std::size_t _M_bucket;
std::size_t _M_bucket_count;
};
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash, bool __cache>
inline bool
operator==(const _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>& __x,
const _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>& __y)
{ return __x._M_cur == __y._M_cur; }
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash, bool __cache>
inline bool
operator!=(const _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>& __x,
const _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>& __y)
{ return __x._M_cur != __y._M_cur; }
/// local iterators
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash,
bool __constant_iterators, bool __cache>
struct _Local_iterator
: public _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>
{
private:
using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>;
using __hash_code_base = typename __base_type::__hash_code_base;
public:
typedef _Value value_type;
typedef typename std::conditional<__constant_iterators,
const _Value*, _Value*>::type
pointer;
typedef typename std::conditional<__constant_iterators,
const _Value&, _Value&>::type
reference;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
_Local_iterator() = default;
_Local_iterator(const __hash_code_base& __base,
_Hash_node<_Value, __cache>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: __base_type(__base, __p, __bkt, __bkt_count)
{ }
reference
operator*() const
{ return this->_M_cur->_M_v; }
pointer
operator->() const
{ return std::__addressof(this->_M_cur->_M_v); }
_Local_iterator&
operator++()
{
this->_M_incr();
return *this;
}
_Local_iterator
operator++(int)
{
_Local_iterator __tmp(*this);
this->_M_incr();
return __tmp;
}
};
/// local const_iterators
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash,
bool __constant_iterators, bool __cache>
struct _Local_const_iterator
: public _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>
{
private:
using __base_type = _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache>;
using __hash_code_base = typename __base_type::__hash_code_base;
public:
typedef _Value value_type;
typedef const _Value* pointer;
typedef const _Value& reference;
typedef std::ptrdiff_t difference_type;
typedef std::forward_iterator_tag iterator_category;
_Local_const_iterator() = default;
_Local_const_iterator(const __hash_code_base& __base,
_Hash_node<_Value, __cache>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: __base_type(__base, __p, __bkt, __bkt_count)
{ }
_Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash,
__constant_iterators,
__cache>& __x)
: __base_type(__x)
{ }
reference
operator*() const
{ return this->_M_cur->_M_v; }
pointer
operator->() const
{ return std::__addressof(this->_M_cur->_M_v); }
_Local_const_iterator&
operator++()
{
this->_M_incr();
return *this;
}
_Local_const_iterator
operator++(int)
{
_Local_const_iterator __tmp(*this);
this->_M_incr();
return __tmp;
}
};
/**
* Primary class template _Hashtable_base.
*
* Helper class adding management of _Equal functor to
* _Hash_code_base type.
*
* Base class templates are:
* - __detail::_Hash_code_base
* - __detail::_Hashtable_ebo_helper
*/
template<typename _Key, typename _Value,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash, typename _Traits>
struct _Hashtable_base
: public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
_Traits::__hash_cached::value>,
private _Hashtable_ebo_helper<0, _Equal>
{
public:
typedef _Key key_type;
typedef _Value value_type;
typedef _Equal key_equal;
typedef std::size_t size_type;
typedef std::ptrdiff_t difference_type;
using __traits_type = _Traits;
using __hash_cached = typename __traits_type::__hash_cached;
using __constant_iterators = typename __traits_type::__constant_iterators;
using __unique_keys = typename __traits_type::__unique_keys;
using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash,
__hash_cached::value>;
using __hash_code = typename __hash_code_base::__hash_code;
using __node_type = typename __hash_code_base::__node_type;
using iterator = __detail::_Node_iterator<value_type,
__constant_iterators::value,
__hash_cached::value>;
using const_iterator = __detail::_Node_const_iterator<value_type,
__constant_iterators::value,
__hash_cached::value>;
using local_iterator = __detail::_Local_iterator<key_type, value_type,
_ExtractKey, _H1, _H2, _Hash,
__constant_iterators::value,
__hash_cached::value>;
using const_local_iterator = __detail::_Local_const_iterator<key_type,
value_type,
_ExtractKey, _H1, _H2, _Hash,
__constant_iterators::value,
__hash_cached::value>;
using __ireturn_type = typename std::conditional<__unique_keys::value,
std::pair<iterator, bool>,
iterator>::type;
using __iconv_type = typename std::conditional<__unique_keys::value,
_Select1st, _Identity
>::type;
private:
using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>;
using _EqualHelper = _Equal_helper<_Key, _Value, _ExtractKey, _Equal,
__hash_code, __hash_cached::value>;
protected:
using __node_base = __detail::_Hash_node_base;
using __bucket_type = __node_base*;
_Hashtable_base(const _ExtractKey& __ex, const _H1& __h1, const _H2& __h2,
const _Hash& __hash, const _Equal& __eq)
: __hash_code_base(__ex, __h1, __h2, __hash), _EqualEBO(__eq)
{ }
bool
_M_equals(const _Key& __k, __hash_code __c, __node_type* __n) const
{
return _EqualHelper::_S_equals(_M_eq(), this->_M_extract(),
__k, __c, __n);
}
void
_M_swap(_Hashtable_base& __x)
{
__hash_code_base::_M_swap(__x);
std::swap(_M_eq(), __x._M_eq());
}
const _Equal&
_M_eq() const { return _EqualEBO::_S_cget(*this); }
_Equal&
_M_eq() { return _EqualEBO::_S_get(*this); }
};
/**
* struct _Equality_base.
*
* Common types and functions for class _Equality.
*/
struct _Equality_base
{
protected:
template<typename _Uiterator>
static bool
_S_is_permutation(_Uiterator, _Uiterator, _Uiterator);
};
// See std::is_permutation in N3068.
template<typename _Uiterator>
bool
_Equality_base::
_S_is_permutation(_Uiterator __first1, _Uiterator __last1,
_Uiterator __first2)
{
for (; __first1 != __last1; ++__first1, ++__first2)
if (!(*__first1 == *__first2))
break;
if (__first1 == __last1)
return true;
_Uiterator __last2 = __first2;
std::advance(__last2, std::distance(__first1, __last1));
for (_Uiterator __it1 = __first1; __it1 != __last1; ++__it1)
{
_Uiterator __tmp = __first1;
while (__tmp != __it1 && !bool(*__tmp == *__it1))
++__tmp;
// We've seen this one before.
if (__tmp != __it1)
continue;
std::ptrdiff_t __n2 = 0;
for (__tmp = __first2; __tmp != __last2; ++__tmp)
if (*__tmp == *__it1)
++__n2;
if (!__n2)
return false;
std::ptrdiff_t __n1 = 0;
for (__tmp = __it1; __tmp != __last1; ++__tmp)
if (*__tmp == *__it1)
++__n1;
if (__n1 != __n2)
return false;
}
return true;
}
/**
* Primary class template _Equality.
*
* This is for implementing equality comparison for unordered
* containers, per N3068, by John Lakos and Pablo Halpern.
* Algorithmically, we follow closely the reference implementations
* therein.
*/
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits,
bool _Unique_keys = _Traits::__unique_keys::value>
struct _Equality;
/// Specialization.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>
{
using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits>;
bool
_M_equal(const __hashtable&) const;
};
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
bool
_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
_M_equal(const __hashtable& __other) const
{
const __hashtable* __this = static_cast<const __hashtable*>(this);
if (__this->size() != __other.size())
return false;
for (auto __itx = __this->begin(); __itx != __this->end(); ++__itx)
{
const auto __ity = __other.find(_ExtractKey()(*__itx));
if (__ity == __other.end() || !bool(*__ity == *__itx))
return false;
}
return true;
}
/// Specialization.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, false>
: public _Equality_base
{
using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits>;
bool
_M_equal(const __hashtable&) const;
};
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
bool
_Equality<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, false>::
_M_equal(const __hashtable& __other) const
{
const __hashtable* __this = static_cast<const __hashtable*>(this);
if (__this->size() != __other.size())
return false;
for (auto __itx = __this->begin(); __itx != __this->end();)
{
const auto __xrange = __this->equal_range(_ExtractKey()(*__itx));
const auto __yrange = __other.equal_range(_ExtractKey()(*__itx));
if (std::distance(__xrange.first, __xrange.second)
!= std::distance(__yrange.first, __yrange.second))
return false;
if (!_S_is_permutation(__xrange.first, __xrange.second,
__yrange.first))
return false;
__itx = __xrange.second;
}
return true;
}
/**
* This type is to combine a _Hash_node_base instance with an allocator
* instance through inheritance to benefit from EBO when possible.
*/
template<typename _NodeAlloc>
struct _Before_begin : public _NodeAlloc
{
_Hash_node_base _M_node;
_Before_begin(const _Before_begin&) = default;
_Before_begin(_Before_begin&&) = default;
template<typename _Alloc>
_Before_begin(_Alloc&& __a)
: _NodeAlloc(std::forward<_Alloc>(__a))
{ }
};
//@} hashtable-detail
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace __detail
} // namespace std
#endif // _HASHTABLE_POLICY_H