hashtable_policy.h
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// Internal policy header for unordered_set and unordered_map -*- C++ -*-
// Copyright (C) 2010-2018 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
#include <tuple> // for std::tuple, std::forward_as_tuple
#include <cstdint> // for std::uint_fast64_t
#include <bits/stl_algobase.h> // for std::min.
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;
namespace __detail
{
/**
* @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 0/1 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 __first != __last ? 1 : 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)
{ return __distance_fw(__first, __last,
std::__iterator_category(__first)); }
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)); }
};
template<typename _NodeAlloc>
struct _Hashtable_alloc;
// Functor recycling a pool of nodes and using allocation once the pool is
// empty.
template<typename _NodeAlloc>
struct _ReuseOrAllocNode
{
private:
using __node_alloc_type = _NodeAlloc;
using __hashtable_alloc = _Hashtable_alloc<__node_alloc_type>;
using __node_alloc_traits =
typename __hashtable_alloc::__node_alloc_traits;
using __node_type = typename __hashtable_alloc::__node_type;
public:
_ReuseOrAllocNode(__node_type* __nodes, __hashtable_alloc& __h)
: _M_nodes(__nodes), _M_h(__h) { }
_ReuseOrAllocNode(const _ReuseOrAllocNode&) = delete;
~_ReuseOrAllocNode()
{ _M_h._M_deallocate_nodes(_M_nodes); }
template<typename _Arg>
__node_type*
operator()(_Arg&& __arg) const
{
if (_M_nodes)
{
__node_type* __node = _M_nodes;
_M_nodes = _M_nodes->_M_next();
__node->_M_nxt = nullptr;
auto& __a = _M_h._M_node_allocator();
__node_alloc_traits::destroy(__a, __node->_M_valptr());
__try
{
__node_alloc_traits::construct(__a, __node->_M_valptr(),
std::forward<_Arg>(__arg));
}
__catch(...)
{
__node->~__node_type();
__node_alloc_traits::deallocate(__a, __node, 1);
__throw_exception_again;
}
return __node;
}
return _M_h._M_allocate_node(std::forward<_Arg>(__arg));
}
private:
mutable __node_type* _M_nodes;
__hashtable_alloc& _M_h;
};
// Functor similar to the previous one but without any pool of nodes to
// recycle.
template<typename _NodeAlloc>
struct _AllocNode
{
private:
using __hashtable_alloc = _Hashtable_alloc<_NodeAlloc>;
using __node_type = typename __hashtable_alloc::__node_type;
public:
_AllocNode(__hashtable_alloc& __h)
: _M_h(__h) { }
template<typename _Arg>
__node_type*
operator()(_Arg&& __arg) const
{ return _M_h._M_allocate_node(std::forward<_Arg>(__arg)); }
private:
__hashtable_alloc& _M_h;
};
// 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
{
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() noexcept : _M_nxt() { }
_Hash_node_base(_Hash_node_base* __next) noexcept : _M_nxt(__next) { }
};
/**
* struct _Hash_node_value_base
*
* Node type with the value to store.
*/
template<typename _Value>
struct _Hash_node_value_base : _Hash_node_base
{
typedef _Value value_type;
__gnu_cxx::__aligned_buffer<_Value> _M_storage;
_Value*
_M_valptr() noexcept
{ return _M_storage._M_ptr(); }
const _Value*
_M_valptr() const noexcept
{ return _M_storage._M_ptr(); }
_Value&
_M_v() noexcept
{ return *_M_valptr(); }
const _Value&
_M_v() const noexcept
{ return *_M_valptr(); }
};
/**
* 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_value_base.
*/
template<typename _Value>
struct _Hash_node<_Value, true> : _Hash_node_value_base<_Value>
{
std::size_t _M_hash_code;
_Hash_node*
_M_next() const noexcept
{ return static_cast<_Hash_node*>(this->_M_nxt); }
};
/**
* Specialization for nodes without caches, struct _Hash_node.
*
* Base class is __detail::_Hash_node_value_base.
*/
template<typename _Value>
struct _Hash_node<_Value, false> : _Hash_node_value_base<_Value>
{
_Hash_node*
_M_next() const noexcept
{ return static_cast<_Hash_node*>(this->_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) noexcept
: _M_cur(__p) { }
void
_M_incr() noexcept
{ _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)
noexcept
{ 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)
noexcept
{ 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() noexcept
: __base_type(0) { }
explicit
_Node_iterator(__node_type* __p) noexcept
: __base_type(__p) { }
reference
operator*() const noexcept
{ return this->_M_cur->_M_v(); }
pointer
operator->() const noexcept
{ return this->_M_cur->_M_valptr(); }
_Node_iterator&
operator++() noexcept
{
this->_M_incr();
return *this;
}
_Node_iterator
operator++(int) noexcept
{
_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() noexcept
: __base_type(0) { }
explicit
_Node_const_iterator(__node_type* __p) noexcept
: __base_type(__p) { }
_Node_const_iterator(const _Node_iterator<_Value, __constant_iterators,
__cache>& __x) noexcept
: __base_type(__x._M_cur) { }
reference
operator*() const noexcept
{ return this->_M_cur->_M_v(); }
pointer
operator->() const noexcept
{ return this->_M_cur->_M_valptr(); }
_Node_const_iterator&
operator++() noexcept
{
this->_M_incr();
return *this;
}
_Node_const_iterator
operator++(int) noexcept
{
_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 noexcept
{ 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
{
using __has_load_factor = std::true_type;
_Prime_rehash_policy(float __z = 1.0) noexcept
: _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() noexcept
{ _M_next_resize = 0; }
void
_M_reset(_State __state)
{ _M_next_resize = __state; }
static const std::size_t _S_growth_factor = 2;
float _M_max_load_factor;
mutable std::size_t _M_next_resize;
};
/// Range hashing function assuming that second arg is a power of 2.
struct _Mask_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 noexcept
{ return __num & (__den - 1); }
};
/// Compute closest power of 2.
_GLIBCXX14_CONSTEXPR
inline std::size_t
__clp2(std::size_t __n) noexcept
{
#if __SIZEOF_SIZE_T__ >= 8
std::uint_fast64_t __x = __n;
#else
std::uint_fast32_t __x = __n;
#endif
// Algorithm from Hacker's Delight, Figure 3-3.
__x = __x - 1;
__x = __x | (__x >> 1);
__x = __x | (__x >> 2);
__x = __x | (__x >> 4);
__x = __x | (__x >> 8);
__x = __x | (__x >>16);
#if __SIZEOF_SIZE_T__ >= 8
__x = __x | (__x >>32);
#endif
return __x + 1;
}
/// Rehash policy providing power of 2 bucket numbers. Avoids modulo
/// operations.
struct _Power2_rehash_policy
{
using __has_load_factor = std::true_type;
_Power2_rehash_policy(float __z = 1.0) noexcept
: _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 (as long as n is not above the
// highest power of 2).
std::size_t
_M_next_bkt(std::size_t __n) noexcept
{
const auto __max_width = std::min<size_t>(sizeof(size_t), 8);
const auto __max_bkt = size_t(1) << (__max_width * __CHAR_BIT__ - 1);
std::size_t __res = __clp2(__n);
if (__res == __n)
__res <<= 1;
if (__res == 0)
__res = __max_bkt;
if (__res == __max_bkt)
// Set next resize to the max value so that we never try to rehash again
// as we already reach the biggest possible bucket number.
// Note that it might result in max_load_factor not being respected.
_M_next_resize = std::size_t(-1);
else
_M_next_resize
= __builtin_ceil(__res * (long double)_M_max_load_factor);
return __res;
}
// Return a bucket count appropriate for n elements
std::size_t
_M_bkt_for_elements(std::size_t __n) const noexcept
{ 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) noexcept
{
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(std::max<std::size_t>(__builtin_floor(__min_bkts) + 1,
__n_bkt * _S_growth_factor)));
_M_next_resize
= __builtin_floor(__n_bkt * (long double)_M_max_load_factor);
return std::make_pair(false, 0);
}
else
return std::make_pair(false, 0);
}
typedef std::size_t _State;
_State
_M_state() const noexcept
{ return _M_next_resize; }
void
_M_reset() noexcept
{ _M_next_resize = 0; }
void
_M_reset(_State __state) noexcept
{ _M_next_resize = __state; }
static const std::size_t _S_growth_factor = 2;
float _M_max_load_factor;
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>
auto
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
operator[](const key_type& __k)
-> mapped_type&
{
__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>
auto
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
operator[](key_type&& __k)
-> mapped_type&
{
__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>
auto
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
at(const key_type& __k)
-> mapped_type&
{
__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>
auto
_Map_base<_Key, _Pair, _Alloc, _Select1st, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits, true>::
at(const key_type& __k) const
-> const mapped_type&
{
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.
*
* Defines @c 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
{
protected:
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 __node_type = _Hash_node<_Value, _Traits::__hash_cached::value>;
using __node_alloc_type = __alloc_rebind<_Alloc, __node_type>;
using __node_gen_type = _AllocNode<__node_alloc_type>;
__hashtable&
_M_conjure_hashtable()
{ return *(static_cast<__hashtable*>(this)); }
template<typename _InputIterator, typename _NodeGetter>
void
_M_insert_range(_InputIterator __first, _InputIterator __last,
const _NodeGetter&, true_type);
template<typename _InputIterator, typename _NodeGetter>
void
_M_insert_range(_InputIterator __first, _InputIterator __last,
const _NodeGetter&, false_type);
public:
__ireturn_type
insert(const value_type& __v)
{
__hashtable& __h = _M_conjure_hashtable();
__node_gen_type __node_gen(__h);
return __h._M_insert(__v, __node_gen, __unique_keys());
}
iterator
insert(const_iterator __hint, const value_type& __v)
{
__hashtable& __h = _M_conjure_hashtable();
__node_gen_type __node_gen(__h);
return __h._M_insert(__hint, __v, __node_gen, __unique_keys());
}
void
insert(initializer_list<value_type> __l)
{ this->insert(__l.begin(), __l.end()); }
template<typename _InputIterator>
void
insert(_InputIterator __first, _InputIterator __last)
{
__hashtable& __h = _M_conjure_hashtable();
__node_gen_type __node_gen(__h);
return _M_insert_range(__first, __last, __node_gen, __unique_keys());
}
};
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
template<typename _InputIterator, typename _NodeGetter>
void
_Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>::
_M_insert_range(_InputIterator __first, _InputIterator __last,
const _NodeGetter& __node_gen, true_type)
{
size_type __n_elt = __detail::__distance_fw(__first, __last);
if (__n_elt == 0)
return;
__hashtable& __h = _M_conjure_hashtable();
for (; __first != __last; ++__first)
{
if (__h._M_insert(*__first, __node_gen, __unique_keys(),
__n_elt).second)
__n_elt = 1;
else if (__n_elt != 1)
--__n_elt;
}
}
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
template<typename _InputIterator, typename _NodeGetter>
void
_Insert_base<_Key, _Value, _Alloc, _ExtractKey, _Equal, _H1, _H2, _Hash,
_RehashPolicy, _Traits>::
_M_insert_range(_InputIterator __first, _InputIterator __last,
const _NodeGetter& __node_gen, false_type)
{
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);
if (__n_elt == 0)
return;
__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)
__h._M_insert(*__first, __node_gen, __unique_keys());
}
/**
* Primary class template _Insert.
*
* Defines @c insert member functions that depend on _Hashtable policies,
* via partial specializations.
*/
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>
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>
: 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 __hashtable_base = _Hashtable_base<_Key, _Value, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_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 __ireturn_type = typename __hashtable_base::__ireturn_type;
using __hashtable = typename __base_type::__hashtable;
using __node_gen_type = typename __base_type::__node_gen_type;
using __base_type::insert;
__ireturn_type
insert(value_type&& __v)
{
__hashtable& __h = this->_M_conjure_hashtable();
__node_gen_type __node_gen(__h);
return __h._M_insert(std::move(__v), __node_gen, __unique_keys());
}
iterator
insert(const_iterator __hint, value_type&& __v)
{
__hashtable& __h = this->_M_conjure_hashtable();
__node_gen_type __node_gen(__h);
return __h._M_insert(__hint, std::move(__v), __node_gen,
__unique_keys());
}
};
/// 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, 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 __ireturn_type = typename __base_type::__ireturn_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 __hint, _Pair&& __v)
{
__hashtable& __h = this->_M_conjure_hashtable();
return __h._M_emplace(__hint, __unique_keys(),
std::forward<_Pair>(__v));
}
};
template<typename _Policy>
using __has_load_factor = typename _Policy::__has_load_factor;
/**
* Primary class template _Rehash_base.
*
* Give hashtable the max_load_factor functions and reserve iff the
* rehash policy supports it.
*/
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits,
typename =
__detected_or_t<std::false_type, __has_load_factor, _RehashPolicy>>
struct _Rehash_base;
/// Specialization when rehash policy doesn't provide load factor management.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits,
std::false_type>
{
};
/// Specialization when rehash policy provide load factor management.
template<typename _Key, typename _Value, typename _Alloc,
typename _ExtractKey, typename _Equal,
typename _H1, typename _H2, typename _Hash,
typename _RehashPolicy, typename _Traits>
struct _Rehash_base<_Key, _Value, _Alloc, _ExtractKey, _Equal,
_H1, _H2, _Hash, _RehashPolicy, _Traits,
std::true_type>
{
using __hashtable = _Hashtable<_Key, _Value, _Alloc, _ExtractKey,
_Equal, _H1, _H2, _Hash,
_RehashPolicy, _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(_RehashPolicy(__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 (the type is not
* final) and when it is worth it (the 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;
template<typename _OtherTp>
_Hashtable_ebo_helper(_OtherTp&& __tp)
: _Tp(std::forward<_OtherTp>(__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;
template<typename _OtherTp>
_Hashtable_ebo_helper(_OtherTp&& __tp)
: _M_tp(std::forward<_OtherTp>(__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 and _Hashtable
// default constructor.
_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
noexcept( noexcept(declval<const _Hash&>()(declval<const _Key&>(),
(std::size_t)0)) )
{ 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>;
// Gives the local iterator implementation access to _M_bucket_index().
friend struct _Local_iterator_base<_Key, _Value, _ExtractKey, _H1, _H2,
_Default_ranged_hash, false>;
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 and _Hashtable
// default constructor.
_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
{
static_assert(__is_invocable<const _H1&, const _Key&>{},
"hash function must be invocable with an argument of key type");
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
noexcept( noexcept(declval<const _H1&>()(declval<const _Key&>()))
&& noexcept(declval<const _H2&>()((__hash_code)0,
(std::size_t)0)) )
{ 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 the local iterator implementation access to _M_h2().
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;
// We need the default constructor for _Hashtable default constructor.
_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
{
static_assert(__is_invocable<const _H1&, const _Key&>{},
"hash function must be invocable with an argument of key type");
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
noexcept( noexcept(declval<const _H2&>()((__hash_code)0,
(std::size_t)0)) )
{ 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())); }
};
/// Partial specialization used when nodes contain a cached hash code.
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>;
_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;
public:
const void*
_M_curr() const { return _M_cur; } // for equality ops
std::size_t
_M_get_bucket() const { return _M_bucket; } // for debug mode
};
// Uninitialized storage for a _Hash_code_base.
// This type is DefaultConstructible and Assignable even if the
// _Hash_code_base type isn't, so that _Local_iterator_base<..., false>
// can be DefaultConstructible and Assignable.
template<typename _Tp, bool _IsEmpty = std::is_empty<_Tp>::value>
struct _Hash_code_storage
{
__gnu_cxx::__aligned_buffer<_Tp> _M_storage;
_Tp*
_M_h() { return _M_storage._M_ptr(); }
const _Tp*
_M_h() const { return _M_storage._M_ptr(); }
};
// Empty partial specialization for empty _Hash_code_base types.
template<typename _Tp>
struct _Hash_code_storage<_Tp, true>
{
static_assert( std::is_empty<_Tp>::value, "Type must be empty" );
// As _Tp is an empty type there will be no bytes written/read through
// the cast pointer, so no strict-aliasing violation.
_Tp*
_M_h() { return reinterpret_cast<_Tp*>(this); }
const _Tp*
_M_h() const { return reinterpret_cast<const _Tp*>(this); }
};
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash>
using __hash_code_for_local_iter
= _Hash_code_storage<_Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>>;
// Partial specialization used when hash codes are not cached
template<typename _Key, typename _Value, typename _ExtractKey,
typename _H1, typename _H2, typename _Hash>
struct _Local_iterator_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>
: __hash_code_for_local_iter<_Key, _Value, _ExtractKey, _H1, _H2, _Hash>
{
protected:
using __hash_code_base = _Hash_code_base<_Key, _Value, _ExtractKey,
_H1, _H2, _Hash, false>;
_Local_iterator_base() : _M_bucket_count(-1) { }
_Local_iterator_base(const __hash_code_base& __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)
{ _M_init(__base); }
~_Local_iterator_base()
{
if (_M_bucket_count != -1)
_M_destroy();
}
_Local_iterator_base(const _Local_iterator_base& __iter)
: _M_cur(__iter._M_cur), _M_bucket(__iter._M_bucket),
_M_bucket_count(__iter._M_bucket_count)
{
if (_M_bucket_count != -1)
_M_init(*__iter._M_h());
}
_Local_iterator_base&
operator=(const _Local_iterator_base& __iter)
{
if (_M_bucket_count != -1)
_M_destroy();
_M_cur = __iter._M_cur;
_M_bucket = __iter._M_bucket;
_M_bucket_count = __iter._M_bucket_count;
if (_M_bucket_count != -1)
_M_init(*__iter._M_h());
return *this;
}
void
_M_incr()
{
_M_cur = _M_cur->_M_next();
if (_M_cur)
{
std::size_t __bkt = this->_M_h()->_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;
void
_M_init(const __hash_code_base& __base)
{ ::new(this->_M_h()) __hash_code_base(__base); }
void
_M_destroy() { this->_M_h()->~__hash_code_base(); }
public:
const void*
_M_curr() const { return _M_cur; } // for equality ops and debug mode
std::size_t
_M_get_bucket() const { return _M_bucket; } // for debug mode
};
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_curr() == __y._M_curr(); }
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_curr() != __y._M_curr(); }
/// 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 this->_M_cur->_M_valptr(); }
_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 this->_M_cur->_M_valptr(); }
_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;
private:
using _EqualEBO = _Hashtable_ebo_helper<0, _Equal>;
using _EqualHelper = _Equal_helper<_Key, _Value, _ExtractKey, _Equal,
__hash_code, __hash_cached::value>;
protected:
_Hashtable_base() = default;
_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
{
static_assert(__is_invocable<const _Equal&, const _Key&, const _Key&>{},
"key equality predicate must be invocable with two arguments of "
"key type");
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 deals with all allocation and keeps an allocator instance through
* inheritance to benefit from EBO when possible.
*/
template<typename _NodeAlloc>
struct _Hashtable_alloc : private _Hashtable_ebo_helper<0, _NodeAlloc>
{
private:
using __ebo_node_alloc = _Hashtable_ebo_helper<0, _NodeAlloc>;
public:
using __node_type = typename _NodeAlloc::value_type;
using __node_alloc_type = _NodeAlloc;
// Use __gnu_cxx to benefit from _S_always_equal and al.
using __node_alloc_traits = __gnu_cxx::__alloc_traits<__node_alloc_type>;
using __value_alloc_traits = typename __node_alloc_traits::template
rebind_traits<typename __node_type::value_type>;
using __node_base = __detail::_Hash_node_base;
using __bucket_type = __node_base*;
using __bucket_alloc_type =
__alloc_rebind<__node_alloc_type, __bucket_type>;
using __bucket_alloc_traits = std::allocator_traits<__bucket_alloc_type>;
_Hashtable_alloc() = default;
_Hashtable_alloc(const _Hashtable_alloc&) = default;
_Hashtable_alloc(_Hashtable_alloc&&) = default;
template<typename _Alloc>
_Hashtable_alloc(_Alloc&& __a)
: __ebo_node_alloc(std::forward<_Alloc>(__a))
{ }
__node_alloc_type&
_M_node_allocator()
{ return __ebo_node_alloc::_S_get(*this); }
const __node_alloc_type&
_M_node_allocator() const
{ return __ebo_node_alloc::_S_cget(*this); }
template<typename... _Args>
__node_type*
_M_allocate_node(_Args&&... __args);
void
_M_deallocate_node(__node_type* __n);
// Deallocate the linked list of nodes pointed to by __n
void
_M_deallocate_nodes(__node_type* __n);
__bucket_type*
_M_allocate_buckets(std::size_t __n);
void
_M_deallocate_buckets(__bucket_type*, std::size_t __n);
};
// Definitions of class template _Hashtable_alloc's out-of-line member
// functions.
template<typename _NodeAlloc>
template<typename... _Args>
typename _Hashtable_alloc<_NodeAlloc>::__node_type*
_Hashtable_alloc<_NodeAlloc>::_M_allocate_node(_Args&&... __args)
{
auto __nptr = __node_alloc_traits::allocate(_M_node_allocator(), 1);
__node_type* __n = std::__to_address(__nptr);
__try
{
::new ((void*)__n) __node_type;
__node_alloc_traits::construct(_M_node_allocator(),
__n->_M_valptr(),
std::forward<_Args>(__args)...);
return __n;
}
__catch(...)
{
__node_alloc_traits::deallocate(_M_node_allocator(), __nptr, 1);
__throw_exception_again;
}
}
template<typename _NodeAlloc>
void
_Hashtable_alloc<_NodeAlloc>::_M_deallocate_node(__node_type* __n)
{
typedef typename __node_alloc_traits::pointer _Ptr;
auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__n);
__node_alloc_traits::destroy(_M_node_allocator(), __n->_M_valptr());
__n->~__node_type();
__node_alloc_traits::deallocate(_M_node_allocator(), __ptr, 1);
}
template<typename _NodeAlloc>
void
_Hashtable_alloc<_NodeAlloc>::_M_deallocate_nodes(__node_type* __n)
{
while (__n)
{
__node_type* __tmp = __n;
__n = __n->_M_next();
_M_deallocate_node(__tmp);
}
}
template<typename _NodeAlloc>
typename _Hashtable_alloc<_NodeAlloc>::__bucket_type*
_Hashtable_alloc<_NodeAlloc>::_M_allocate_buckets(std::size_t __n)
{
__bucket_alloc_type __alloc(_M_node_allocator());
auto __ptr = __bucket_alloc_traits::allocate(__alloc, __n);
__bucket_type* __p = std::__to_address(__ptr);
__builtin_memset(__p, 0, __n * sizeof(__bucket_type));
return __p;
}
template<typename _NodeAlloc>
void
_Hashtable_alloc<_NodeAlloc>::_M_deallocate_buckets(__bucket_type* __bkts,
std::size_t __n)
{
typedef typename __bucket_alloc_traits::pointer _Ptr;
auto __ptr = std::pointer_traits<_Ptr>::pointer_to(*__bkts);
__bucket_alloc_type __alloc(_M_node_allocator());
__bucket_alloc_traits::deallocate(__alloc, __ptr, __n);
}
//@} hashtable-detail
} // namespace __detail
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // _HASHTABLE_POLICY_H
std::tuple_element
tuple_element
Definition: array:359
std::iterator
Common iterator class.
Definition: stl_iterator_base_types.h:118
std::__detail::_Prime_rehash_policy
Default value for rehash policy. Bucket size is (usually) the smallest prime that keeps the load fact...
Definition: hashtable_policy.h:446
stl_algobase.h
std::__detail::_Insert
Definition: hashtable_policy.h:929
std::__detail::_Local_const_iterator
local const_iterators
Definition: hashtable_policy.h:1712
std::__detail::_Hash_node< _Value, true >
Definition: hashtable_policy.h:265
std::pair
Struct holding two objects of arbitrary type.
Definition: stl_pair.h:208
std::true_type
integral_constant< bool, true > true_type
The type used as a compile-time boolean with true value.
Definition: type_traits:75
std::input_iterator_tag
Marking input iterators.
Definition: stl_iterator_base_types.h:89
std::__detail::_Power2_rehash_policy
Rehash policy providing power of 2 bucket numbers. Avoids modulo operations.
Definition: hashtable_policy.h:532
std::__detail::_Default_ranged_hash
Default ranged hash function H. In principle it should be a function object composed from objects of ...
Definition: hashtable_policy.h:442
std::__detail::_Hashtable_ebo_helper
Definition: hashtable_policy.h:1099
std::__detail::_Equality
Definition: hashtable_policy.h:1934
std::__detail::_Insert_base
Definition: hashtable_policy.h:792
std::_Hashtable
Definition: bits/hashtable.h:173
std::piecewise_construct
constexpr _GLIBCXX17_INLINE piecewise_construct_t piecewise_construct
piecewise_construct
Definition: stl_pair.h:79
std::is_constructible
is_constructible
Definition: type_traits:872
std::distance
_GLIBCXX17_CONSTEXPR iterator_traits< _InputIterator >::difference_type distance(_InputIterator __first, _InputIterator __last)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:138
std::make_pair
constexpr pair< typename __decay_and_strip< _T1 >::__type, typename __decay_and_strip< _T2 >::__type > make_pair(_T1 &&__x, _T2 &&__y)
A convenience wrapper for creating a pair from two objects.
Definition: stl_pair.h:524
std::__detail::_Node_iterator_base
Base class for node iterators.
Definition: hashtable_policy.h:289
std::is_empty
is_empty
Definition: type_traits:692
std::__detail::_Hash_node_base
Definition: hashtable_policy.h:215
std::forward_iterator_tag
Forward iterators support a superset of input iterator operations.
Definition: stl_iterator_base_types.h:95
std::initializer_list
initializer_list
Definition: initializer_list:47
std::__detail::_Node_const_iterator
Node const_iterators, used to iterate through all the hashtable.
Definition: hashtable_policy.h:370
tuple
std::__detail::_Hash_node< _Value, false >
Definition: hashtable_policy.h:280
std::__detail::_Mask_range_hashing
Range hashing function assuming that second arg is a power of 2.
Definition: hashtable_policy.h:495
std::tuple
Primary class template, tuple.
Definition: tuple:53
std::false_type
integral_constant< bool, false > false_type
The type used as a compile-time boolean with false value.
Definition: type_traits:78
std::operator*
complex< _Tp > operator*(const complex< _Tp > &__x, const complex< _Tp > &__y)
Return new complex value x times y.
Definition: complex:386
std::forward
constexpr _Tp && forward(typename std::remove_reference< _Tp >::type &__t) noexcept
Forward an lvalue.
Definition: move.h:74
std::__detail::_Hashtable_base
Definition: hashtable_policy.h:58
std::__detail::_Hash_code_base
Definition: hashtable_policy.h:1179
std::__detail::_Hash_node
Definition: hashtable_policy.h:257
std::__detail::_Hashtable_traits
Definition: hashtable_policy.h:200
std::__detail::_Equal_helper
Definition: hashtable_policy.h:1450
std::__detail::_Node_iterator
Node iterators, used to iterate through all the hashtable.
Definition: hashtable_policy.h:319
std::allocator_traits
Uniform interface to all allocator types.
Definition: bits/alloc_traits.h:83
std::__detail::_Local_iterator
local iterators
Definition: hashtable_policy.h:1657
std::__detail::_Map_base
Definition: hashtable_policy.h:643
std::__detail::_Local_iterator_base
Definition: hashtable_policy.h:1154
std::__detail::_Hash_node_value_base
Definition: hashtable_policy.h:230
std::conditional
Define a member typedef type to one of two argument types.
Definition: type_traits:92
std::__iterator_category
constexpr iterator_traits< _Iter >::iterator_category __iterator_category(const _Iter &)
Definition: stl_iterator_base_types.h:205
std::__detail::_Mod_range_hashing
Default range hashing function: use division to fold a large number into the range [0,...
Definition: hashtable_policy.h:425
std::pointer_traits
Uniform interface to all pointer-like types.
Definition: ptr_traits.h:78
__gnu_cxx::__alloc_traits
Uniform interface to C++98 and C++11 allocators.
Definition: ext/alloc_traits.h:50
std::__detail::_Hashtable_alloc
Definition: hashtable_policy.h:98
std::__detail::_Rehash_base
Definition: hashtable_policy.h:1043
std::enable_if
Define a member typedef type only if a boolean constant is true.
Definition: type_traits:1913
std::integral_constant
integral_constant
Definition: type_traits:57
cstdint
std::__detail::__clp2
_GLIBCXX14_CONSTEXPR std::size_t __clp2(std::size_t __n) noexcept
Compute closest power of 2.
Definition: hashtable_policy.h:510
std::__detail::_Equality_base
Definition: hashtable_policy.h:1867
std::advance
_GLIBCXX17_CONSTEXPR void advance(_InputIterator &__i, _Distance __n)
A generalization of pointer arithmetic.
Definition: stl_iterator_base_funcs.h:202
std
ISO C++ entities toplevel namespace is std.