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d150390867
gcc/libstdc++-v3/include/bits/hashtable_policy.h
Paolo Carlini d150390867 re PR libstdc++/52309 ([c++0x] unordered_set illegally requires value_type::operator!=) 
2012-02-20  Paolo Carlini  <paolo.carlini@oracle.com>

	PR libstdc++/52309
	* include/bits/hashtable_policy.h (_Equality_base<, true,>::
    	_M_equal(const _Hashtable&)): Compare values with operator==.
	* testsuite/23_containers/unordered_set/operators/52309.cc: New.

From-SVN: r184388
2012-02-20 11:11:39 +00:00

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// Internal policy header for unordered_set and unordered_map -*- C++ -*-
// Copyright (C) 2010, 2011, 2012 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)
{
namespace __detail
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// 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 when the hash functor is noexcept qualified or
// not
template <typename _Key, typename _Hash>
struct __is_noexcept_hash : std::integral_constant<bool,
noexcept(declval<const _Hash&>()(declval<const _Key&>()))>
{};
// Auxiliary types used for all instantiations of _Hashtable: nodes
// and iterators.
// 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) { }
};
template<typename _Value, bool __cache_hash_code>
struct _Hash_node;
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); }
};
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); }
};
// Node iterators, used to iterate through all the hashtable.
template<typename _Value, bool __cache>
struct _Node_iterator_base
{
_Node_iterator_base(_Hash_node<_Value, __cache>* __p)
: _M_cur(__p) { }
void
_M_incr()
{ _M_cur = _M_cur->_M_next(); }
_Hash_node<_Value, __cache>* _M_cur;
};
template<typename _Value, bool __cache>
inline bool
operator==(const _Node_iterator_base<_Value, __cache>& __x,
const _Node_iterator_base<_Value, __cache>& __y)
{ return __x._M_cur == __y._M_cur; }
template<typename _Value, bool __cache>
inline bool
operator!=(const _Node_iterator_base<_Value, __cache>& __x,
const _Node_iterator_base<_Value, __cache>& __y)
{ return __x._M_cur != __y._M_cur; }
template<typename _Value, bool __constant_iterators, bool __cache>
struct _Node_iterator
: public _Node_iterator_base<_Value, __cache>
{
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;
_Node_iterator()
: _Node_iterator_base<_Value, __cache>(0) { }
explicit
_Node_iterator(_Hash_node<_Value, __cache>* __p)
: _Node_iterator_base<_Value, __cache>(__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;
}
};
template<typename _Value, bool __constant_iterators, bool __cache>
struct _Node_const_iterator
: public _Node_iterator_base<_Value, __cache>
{
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;
_Node_const_iterator()
: _Node_iterator_base<_Value, __cache>(0) { }
explicit
_Node_const_iterator(_Hash_node<_Value, __cache>* __p)
: _Node_iterator_base<_Value, __cache>(__p) { }
_Node_const_iterator(const _Node_iterator<_Value, __constant_iterators,
__cache>& __x)
: _Node_iterator_base<_Value, __cache>(__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_prev_resize(0), _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;
// __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::pair<std::size_t, std::size_t> _State;
_State
_M_state() const
{ return std::make_pair(_M_prev_resize, _M_next_resize); }
void
_M_reset(const _State& __state)
{
_M_prev_resize = __state.first;
_M_next_resize = __state.second;
}
enum { _S_n_primes = sizeof(unsigned long) != 8 ? 256 : 256 + 48 };
float _M_max_load_factor;
mutable std::size_t _M_prev_resize;
mutable std::size_t _M_next_resize;
};
extern const unsigned long __prime_list[];
// XXX This is a hack. There's no good reason for any of
// _Prime_rehash_policy's member functions to be inline.
// Return a prime no smaller than n.
inline std::size_t
_Prime_rehash_policy::
_M_next_bkt(std::size_t __n) const
{
// Optimize lookups involving the first elements of __prime_list.
// (useful to speed-up, eg, constructors)
static const unsigned char __fast_bkt[12]
= { 2, 2, 2, 3, 5, 5, 7, 7, 11, 11, 11, 11 };
if (__n <= 11)
{
_M_prev_resize = 0;
_M_next_resize
= __builtin_ceil(__fast_bkt[__n] * (long double)_M_max_load_factor);
return __fast_bkt[__n];
}
const unsigned long* __p
= std::lower_bound(__prime_list + 5, __prime_list + _S_n_primes, __n);
// Shrink will take place only if the number of elements is small enough
// so that the prime number 2 steps before __p is large enough to still
// conform to the max load factor:
_M_prev_resize
= __builtin_floor(*(__p - 2) * (long double)_M_max_load_factor);
// Let's guaranty that a minimal grow step of 11 is used
if (*__p - __n < 11)
__p = std::lower_bound(__p, __prime_list + _S_n_primes, __n + 11);
_M_next_resize = __builtin_ceil(*__p * (long double)_M_max_load_factor);
return *__p;
}
// Return the smallest prime p such that alpha p >= n, where alpha
// is the load factor.
inline std::size_t
_Prime_rehash_policy::
_M_bkt_for_elements(std::size_t __n) const
{ return _M_next_bkt(__builtin_ceil(__n / (long double)_M_max_load_factor)); }
// Finds the smallest prime p such that alpha p > __n_elt + __n_ins.
// If p > __n_bkt, return make_pair(true, p); otherwise return
// make_pair(false, 0). In principle this isn't very different from
// _M_bkt_for_elements.
// The only tricky part is that we're caching the element count at
// which we need to rehash, so we don't have to do a floating-point
// multiply for every insertion.
inline std::pair<bool, std::size_t>
_Prime_rehash_policy::
_M_need_rehash(std::size_t __n_bkt, std::size_t __n_elt,
std::size_t __n_ins) const
{
if (__n_elt + __n_ins >= _M_next_resize)
{
long double __min_bkts = (__n_elt + __n_ins)
/ (long double)_M_max_load_factor;
if (__min_bkts >= __n_bkt)
return std::make_pair(true,
_M_next_bkt(__builtin_floor(__min_bkts) + 1));
else
{
_M_next_resize
= __builtin_floor(__n_bkt * (long double)_M_max_load_factor);
return std::make_pair(false, 0);
}
}
else if (__n_elt + __n_ins < _M_prev_resize)
{
long double __min_bkts = (__n_elt + __n_ins)
/ (long double)_M_max_load_factor;
return std::make_pair(true,
_M_next_bkt(__builtin_floor(__min_bkts) + 1));
}
else
return std::make_pair(false, 0);
}
// 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 the "curiously recurring template
// pattern" for them.
// class template _Map_base. If the hashtable has a value type of
// the form pair<T1, T2> and a key extraction policy 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 _Ex, bool __unique,
typename _Hashtable>
struct _Map_base { };
template<typename _Key, typename _Pair, typename _Hashtable>
struct _Map_base<_Key, _Pair, std::_Select1st<_Pair>, false, _Hashtable>
{
typedef typename _Pair::second_type mapped_type;
};
template<typename _Key, typename _Pair, typename _Hashtable>
struct _Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>
{
typedef typename _Pair::second_type mapped_type;
mapped_type&
operator[](const _Key& __k);
mapped_type&
operator[](_Key&& __k);
// _GLIBCXX_RESOLVE_LIB_DEFECTS
// DR 761. unordered_map needs an at() member function.
mapped_type&
at(const _Key& __k);
const mapped_type&
at(const _Key& __k) const;
};
template<typename _Key, typename _Pair, typename _Hashtable>
typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>,
true, _Hashtable>::mapped_type&
_Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>::
operator[](const _Key& __k)
{
_Hashtable* __h = static_cast<_Hashtable*>(this);
typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
typename _Hashtable::_Node* __p = __h->_M_find_node(__n, __k, __code);
if (!__p)
return __h->_M_insert_bucket(std::make_pair(__k, mapped_type()),
__n, __code)->second;
return (__p->_M_v).second;
}
template<typename _Key, typename _Pair, typename _Hashtable>
typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>,
true, _Hashtable>::mapped_type&
_Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>::
operator[](_Key&& __k)
{
_Hashtable* __h = static_cast<_Hashtable*>(this);
typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
typename _Hashtable::_Node* __p = __h->_M_find_node(__n, __k, __code);
if (!__p)
return __h->_M_insert_bucket(std::make_pair(std::move(__k),
mapped_type()),
__n, __code)->second;
return (__p->_M_v).second;
}
template<typename _Key, typename _Pair, typename _Hashtable>
typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>,
true, _Hashtable>::mapped_type&
_Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>::
at(const _Key& __k)
{
_Hashtable* __h = static_cast<_Hashtable*>(this);
typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
typename _Hashtable::_Node* __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 _Hashtable>
const typename _Map_base<_Key, _Pair, std::_Select1st<_Pair>,
true, _Hashtable>::mapped_type&
_Map_base<_Key, _Pair, std::_Select1st<_Pair>, true, _Hashtable>::
at(const _Key& __k) const
{
const _Hashtable* __h = static_cast<const _Hashtable*>(this);
typename _Hashtable::_Hash_code_type __code = __h->_M_hash_code(__k);
std::size_t __n = __h->_M_bucket_index(__k, __code);
typename _Hashtable::_Node* __p = __h->_M_find_node(__n, __k, __code);
if (!__p)
__throw_out_of_range(__N("_Map_base::at"));
return (__p->_M_v).second;
}
// class template _Rehash_base. Give hashtable the max_load_factor
// functions and reserve iff the rehash policy is _Prime_rehash_policy.
template<typename _RehashPolicy, typename _Hashtable>
struct _Rehash_base { };
template<typename _Hashtable>
struct _Rehash_base<_Prime_rehash_policy, _Hashtable>
{
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()));
}
};
// 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;
};
// 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: 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:
typedef _Hashtable_ebo_helper<0, _ExtractKey> _EboExtractKey;
typedef _Hashtable_ebo_helper<1, _Hash> _EboHash;
protected:
// 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)
: _EboExtractKey(__ex), _EboHash(__h) { }
typedef void* _Hash_code_type;
_Hash_code_type
_M_hash_code(const _Key& __key) const
{ return 0; }
std::size_t
_M_bucket_index(const _Key& __k, _Hash_code_type,
std::size_t __n) const
{ return _M_ranged_hash()(__k, __n); }
std::size_t
_M_bucket_index(const _Hash_node<_Value, false>* __p,
std::size_t __n) const
{ return _M_ranged_hash()(_M_extract()(__p->_M_v), __n); }
void
_M_store_code(_Hash_node<_Value, false>*, _Hash_code_type) const
{ }
void
_M_copy_code(_Hash_node<_Value, false>*,
const _Hash_node<_Value, false>*) const
{ }
void
_M_swap(_Hash_code_base& __x)
{
std::swap(_M_extract(), __x._M_extract());
std::swap(_M_ranged_hash(), __x._M_ranged_hash());
}
protected:
const _ExtractKey&
_M_extract() const { return _EboExtractKey::_S_cget(*this); }
_ExtractKey&
_M_extract() { return _EboExtractKey::_S_get(*this); }
const _Hash&
_M_ranged_hash() const { return _EboHash::_S_cget(*this); }
_Hash&
_M_ranged_hash() { return _EboHash::_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 TR1.
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:
typedef _Hashtable_ebo_helper<0, _ExtractKey> _EboExtractKey;
typedef _Hashtable_ebo_helper<1, _H1> _EboH1;
typedef _Hashtable_ebo_helper<2, _H2> _EboH2;
public:
typedef _H1 hasher;
hasher
hash_function() const
{ return _M_h1(); }
protected:
// 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&)
: _EboExtractKey(__ex), _EboH1(__h1), _EboH2(__h2) { }
typedef std::size_t _Hash_code_type;
_Hash_code_type
_M_hash_code(const _Key& __k) const
{ return _M_h1()(__k); }
std::size_t
_M_bucket_index(const _Key&, _Hash_code_type __c,
std::size_t __n) const
{ return _M_h2()(__c, __n); }
std::size_t
_M_bucket_index(const _Hash_node<_Value, false>* __p,
std::size_t __n) const
{ return _M_h2()(_M_h1()(_M_extract()(__p->_M_v)), __n); }
void
_M_store_code(_Hash_node<_Value, false>*, _Hash_code_type) const
{ }
void
_M_copy_code(_Hash_node<_Value, false>*,
const _Hash_node<_Value, false>*) 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());
}
protected:
const _ExtractKey&
_M_extract() const { return _EboExtractKey::_S_cget(*this); }
_ExtractKey&
_M_extract() { return _EboExtractKey::_S_get(*this); }
const _H1&
_M_h1() const { return _EboH1::_S_cget(*this); }
_H1&
_M_h1() { return _EboH1::_S_get(*this); }
const _H2&
_M_h2() const { return _EboH2::_S_cget(*this); }
_H2&
_M_h2() { return _EboH2::_S_get(*this); }
};
// Specialization: hash function and range-hashing function,
// caching hash codes. H is provided but ignored. Provides
// typedef and accessor required by TR1.
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:
typedef _Hashtable_ebo_helper<0, _ExtractKey> _EboExtractKey;
typedef _Hashtable_ebo_helper<1, _H1> _EboH1;
typedef _Hashtable_ebo_helper<2, _H2> _EboH2;
public:
typedef _H1 hasher;
hasher
hash_function() const
{ return _M_h1(); }
protected:
_Hash_code_base(const _ExtractKey& __ex,
const _H1& __h1, const _H2& __h2,
const _Default_ranged_hash&)
: _EboExtractKey(__ex), _EboH1(__h1), _EboH2(__h2) { }
typedef std::size_t _Hash_code_type;
_Hash_code_type
_M_hash_code(const _Key& __k) const
{ return _M_h1()(__k); }
std::size_t
_M_bucket_index(const _Key&, _Hash_code_type __c,
std::size_t __n) const
{ return _M_h2()(__c, __n); }
std::size_t
_M_bucket_index(const _Hash_node<_Value, true>* __p,
std::size_t __n) const
{ return _M_h2()(__p->_M_hash_code, __n); }
void
_M_store_code(_Hash_node<_Value, true>* __n, _Hash_code_type __c) const
{ __n->_M_hash_code = __c; }
void
_M_copy_code(_Hash_node<_Value, true>* __to,
const _Hash_node<_Value, true>* __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());
}
protected:
const _ExtractKey&
_M_extract() const { return _EboExtractKey::_S_cget(*this); }
_ExtractKey&
_M_extract() { return _EboExtractKey::_S_get(*this); }
const _H1&
_M_h1() const { return _EboH1::_S_cget(*this); }
_H1&
_M_h1() { return _EboH1::_S_get(*this); }
const _H2&
_M_h2() const { return _EboH2::_S_cget(*this); }
_H2&
_M_h2() { return _EboH2::_S_get(*this); }
};
template <typename _Key, typename _Value, typename _ExtractKey,
typename _Equal, typename _HashCodeType,
bool __cache_hash_code>
struct _Equal_helper;
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)); }
};
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)); }
};
// Helper class adding management of _Equal functor to _Hash_code_base
// type.
template<typename _Key, typename _Value,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
bool __cache_hash_code>
struct _Hashtable_base
: public _Hash_code_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
__cache_hash_code>,
private _Hashtable_ebo_helper<0, _Equal>
{
private:
typedef _Hashtable_ebo_helper<0, _Equal> _EboEqual;
protected:
typedef _Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, __cache_hash_code> _HCBase;
typedef typename _HCBase::_Hash_code_type _Hash_code_type;
_Hashtable_base(const _ExtractKey& __ex,
const _H1& __h1, const _H2& __h2,
const _Hash& __hash, const _Equal& __eq)
: _HCBase(__ex, __h1, __h2, __hash), _EboEqual(__eq) { }
bool
_M_equals(const _Key& __k, _Hash_code_type __c,
_Hash_node<_Value, __cache_hash_code>* __n) const
{
typedef _Equal_helper<_Key, _Value, _ExtractKey,
_Equal, _Hash_code_type,
__cache_hash_code> _EqualHelper;
return _EqualHelper::_S_equals(_M_eq(), this->_M_extract(),
__k, __c, __n);
}
void
_M_swap(_Hashtable_base& __x)
{
_HCBase::_M_swap(__x);
std::swap(_M_eq(), __x._M_eq());
}
protected:
const _Equal&
_M_eq() const { return _EboEqual::_S_cget(*this); }
_Equal&
_M_eq() { return _EboEqual::_S_get(*this); }
};
// 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;
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 _H2
{
_Local_iterator_base() = default;
_Local_iterator_base(_Hash_node<_Value, true>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: _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 = _M_h2()(_M_cur->_M_hash_code, _M_bucket_count);
if (__bkt != _M_bucket)
_M_cur = nullptr;
}
}
const _H2& _M_h2() const
{ return *this; }
_Hash_node<_Value, true>* _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>
struct _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>
: private _Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>
{
_Local_iterator_base() = default;
_Local_iterator_base(_Hash_node<_Value, false>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: _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; }
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>
{
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;
explicit
_Local_iterator(_Hash_node<_Value, __cache>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
__cache>(__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;
}
};
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>
{
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;
explicit
_Local_const_iterator(_Hash_node<_Value, __cache>* __p,
std::size_t __bkt, std::size_t __bkt_count)
: _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
__cache>(__p, __bkt, __bkt_count)
{ }
_Local_const_iterator(const _Local_iterator<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash,
__constant_iterators,
__cache>& __x)
: _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2, _Hash,
__cache>(__x._M_cur, __x._M_bucket,
__x._M_bucket_count)
{ }
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;
}
};
// Class template _Equality_base. 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 _ExtractKey, bool __unique_keys,
typename _Hashtable>
struct _Equality_base;
template<typename _ExtractKey, typename _Hashtable>
struct _Equality_base<_ExtractKey, true, _Hashtable>
{
bool _M_equal(const _Hashtable&) const;
};
template<typename _ExtractKey, typename _Hashtable>
bool
_Equality_base<_ExtractKey, true, _Hashtable>::
_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;
}
template<typename _ExtractKey, typename _Hashtable>
struct _Equality_base<_ExtractKey, false, _Hashtable>
{
bool _M_equal(const _Hashtable&) const;
private:
template<typename _Uiterator>
static bool
_S_is_permutation(_Uiterator, _Uiterator, _Uiterator);
};
// See std::is_permutation in N3068.
template<typename _ExtractKey, typename _Hashtable>
template<typename _Uiterator>
bool
_Equality_base<_ExtractKey, false, _Hashtable>::
_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;
}
template<typename _ExtractKey, typename _Hashtable>
bool
_Equality_base<_ExtractKey, false, _Hashtable>::
_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;
}
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace __detail
} // namespace std
#endif // _HASHTABLE_POLICY_H
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