hash_map
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// Hashing map implementation -*- C++ -*-
// Copyright (C) 2001-2026 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/>.
/*
* Copyright (c) 1996
* Silicon Graphics Computer Systems, Inc.
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Silicon Graphics makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*
* Copyright (c) 1994
* Hewlett-Packard Company
*
* Permission to use, copy, modify, distribute and sell this software
* and its documentation for any purpose is hereby granted without fee,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation. Hewlett-Packard Company makes no
* representations about the suitability of this software for any
* purpose. It is provided "as is" without express or implied warranty.
*
*/
/** @file backward/hash_map
* This file is a GNU extension to the Standard C++ Library (possibly
* containing extensions from the HP/SGI STL subset).
*/
#ifndef _BACKWARD_HASH_MAP
#define _BACKWARD_HASH_MAP 1
#ifndef _GLIBCXX_PERMIT_BACKWARD_HASH
#include <backward/backward_warning.h>
#endif
#include <bits/c++config.h>
#include <backward/hashtable.h>
#include <bits/concept_check.h>
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
using std::equal_to;
using std::allocator;
using std::pair;
using std::_Select1st;
/**
* This is an SGI extension.
* @ingroup SGIextensions
* @doctodo
*/
template<class _Key, class _Tp, class _HashFn = hash<_Key>,
class _EqualKey = equal_to<_Key>, class _Alloc = allocator<_Tp> >
class hash_map
{
private:
typedef hashtable<pair<const _Key, _Tp>,_Key, _HashFn,
_Select1st<pair<const _Key, _Tp> >,
_EqualKey, _Alloc> _Ht;
_Ht _M_ht;
public:
typedef typename _Ht::key_type key_type;
typedef _Tp data_type;
typedef _Tp mapped_type;
typedef typename _Ht::value_type value_type;
typedef typename _Ht::hasher hasher;
typedef typename _Ht::key_equal key_equal;
typedef typename _Ht::size_type size_type;
typedef typename _Ht::difference_type difference_type;
typedef typename _Ht::pointer pointer;
typedef typename _Ht::const_pointer const_pointer;
typedef typename _Ht::reference reference;
typedef typename _Ht::const_reference const_reference;
typedef typename _Ht::iterator iterator;
typedef typename _Ht::const_iterator const_iterator;
typedef typename _Ht::allocator_type allocator_type;
hasher
hash_funct() const
{ return _M_ht.hash_funct(); }
key_equal
key_eq() const
{ return _M_ht.key_eq(); }
allocator_type
get_allocator() const
{ return _M_ht.get_allocator(); }
hash_map()
: _M_ht(100, hasher(), key_equal(), allocator_type()) {}
explicit
hash_map(size_type __n)
: _M_ht(__n, hasher(), key_equal(), allocator_type()) {}
hash_map(size_type __n, const hasher& __hf)
: _M_ht(__n, __hf, key_equal(), allocator_type()) {}
hash_map(size_type __n, const hasher& __hf, const key_equal& __eql,
const allocator_type& __a = allocator_type())
: _M_ht(__n, __hf, __eql, __a) {}
template<class _InputIterator>
hash_map(_InputIterator __f, _InputIterator __l)
: _M_ht(100, hasher(), key_equal(), allocator_type())
{ _M_ht.insert_unique(__f, __l); }
template<class _InputIterator>
hash_map(_InputIterator __f, _InputIterator __l, size_type __n)
: _M_ht(__n, hasher(), key_equal(), allocator_type())
{ _M_ht.insert_unique(__f, __l); }
template<class _InputIterator>
hash_map(_InputIterator __f, _InputIterator __l, size_type __n,
const hasher& __hf)
: _M_ht(__n, __hf, key_equal(), allocator_type())
{ _M_ht.insert_unique(__f, __l); }
template<class _InputIterator>
hash_map(_InputIterator __f, _InputIterator __l, size_type __n,
const hasher& __hf, const key_equal& __eql,
const allocator_type& __a = allocator_type())
: _M_ht(__n, __hf, __eql, __a)
{ _M_ht.insert_unique(__f, __l); }
size_type
size() const
{ return _M_ht.size(); }
size_type
max_size() const
{ return _M_ht.max_size(); }
_GLIBCXX_NODISCARD bool
empty() const
{ return _M_ht.empty(); }
void
swap(hash_map& __hs)
{ _M_ht.swap(__hs._M_ht); }
template<class _K1, class _T1, class _HF, class _EqK, class _Al>
friend bool
operator== (const hash_map<_K1, _T1, _HF, _EqK, _Al>&,
const hash_map<_K1, _T1, _HF, _EqK, _Al>&);
iterator
begin()
{ return _M_ht.begin(); }
iterator
end()
{ return _M_ht.end(); }
const_iterator
begin() const
{ return _M_ht.begin(); }
const_iterator
end() const
{ return _M_ht.end(); }
pair<iterator, bool>
insert(const value_type& __obj)
{ return _M_ht.insert_unique(__obj); }
template<class _InputIterator>
void
insert(_InputIterator __f, _InputIterator __l)
{ _M_ht.insert_unique(__f, __l); }
pair<iterator, bool>
insert_noresize(const value_type& __obj)
{ return _M_ht.insert_unique_noresize(__obj); }
iterator
find(const key_type& __key)
{ return _M_ht.find(__key); }
const_iterator
find(const key_type& __key) const
{ return _M_ht.find(__key); }
_Tp&
operator[](const key_type& __key)
{ return _M_ht.find_or_insert(value_type(__key, _Tp())).second; }
size_type
count(const key_type& __key) const
{ return _M_ht.count(__key); }
pair<iterator, iterator>
equal_range(const key_type& __key)
{ return _M_ht.equal_range(__key); }
pair<const_iterator, const_iterator>
equal_range(const key_type& __key) const
{ return _M_ht.equal_range(__key); }
size_type
erase(const key_type& __key)
{return _M_ht.erase(__key); }
void
erase(iterator __it)
{ _M_ht.erase(__it); }
void
erase(iterator __f, iterator __l)
{ _M_ht.erase(__f, __l); }
void
clear()
{ _M_ht.clear(); }
void
resize(size_type __hint)
{ _M_ht.resize(__hint); }
size_type
bucket_count() const
{ return _M_ht.bucket_count(); }
size_type
max_bucket_count() const
{ return _M_ht.max_bucket_count(); }
size_type
elems_in_bucket(size_type __n) const
{ return _M_ht.elems_in_bucket(__n); }
};
template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
inline bool
operator==(const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
{ return __hm1._M_ht == __hm2._M_ht; }
template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
inline bool
operator!=(const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
{ return !(__hm1 == __hm2); }
template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
inline void
swap(hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
{ __hm1.swap(__hm2); }
/**
* This is an SGI extension.
* @ingroup SGIextensions
* @doctodo
*/
template<class _Key, class _Tp,
class _HashFn = hash<_Key>,
class _EqualKey = equal_to<_Key>,
class _Alloc = allocator<_Tp> >
class hash_multimap
{
// concept requirements
__glibcxx_class_requires(_Key, _SGIAssignableConcept)
__glibcxx_class_requires(_Tp, _SGIAssignableConcept)
__glibcxx_class_requires3(_HashFn, size_t, _Key, _UnaryFunctionConcept)
__glibcxx_class_requires3(_EqualKey, _Key, _Key, _BinaryPredicateConcept)
private:
typedef hashtable<pair<const _Key, _Tp>, _Key, _HashFn,
_Select1st<pair<const _Key, _Tp> >, _EqualKey, _Alloc>
_Ht;
_Ht _M_ht;
public:
typedef typename _Ht::key_type key_type;
typedef _Tp data_type;
typedef _Tp mapped_type;
typedef typename _Ht::value_type value_type;
typedef typename _Ht::hasher hasher;
typedef typename _Ht::key_equal key_equal;
typedef typename _Ht::size_type size_type;
typedef typename _Ht::difference_type difference_type;
typedef typename _Ht::pointer pointer;
typedef typename _Ht::const_pointer const_pointer;
typedef typename _Ht::reference reference;
typedef typename _Ht::const_reference const_reference;
typedef typename _Ht::iterator iterator;
typedef typename _Ht::const_iterator const_iterator;
typedef typename _Ht::allocator_type allocator_type;
hasher
hash_funct() const
{ return _M_ht.hash_funct(); }
key_equal
key_eq() const
{ return _M_ht.key_eq(); }
allocator_type
get_allocator() const
{ return _M_ht.get_allocator(); }
hash_multimap()
: _M_ht(100, hasher(), key_equal(), allocator_type()) {}
explicit
hash_multimap(size_type __n)
: _M_ht(__n, hasher(), key_equal(), allocator_type()) {}
hash_multimap(size_type __n, const hasher& __hf)
: _M_ht(__n, __hf, key_equal(), allocator_type()) {}
hash_multimap(size_type __n, const hasher& __hf, const key_equal& __eql,
const allocator_type& __a = allocator_type())
: _M_ht(__n, __hf, __eql, __a) {}
template<class _InputIterator>
hash_multimap(_InputIterator __f, _InputIterator __l)
: _M_ht(100, hasher(), key_equal(), allocator_type())
{ _M_ht.insert_equal(__f, __l); }
template<class _InputIterator>
hash_multimap(_InputIterator __f, _InputIterator __l, size_type __n)
: _M_ht(__n, hasher(), key_equal(), allocator_type())
{ _M_ht.insert_equal(__f, __l); }
template<class _InputIterator>
hash_multimap(_InputIterator __f, _InputIterator __l, size_type __n,
const hasher& __hf)
: _M_ht(__n, __hf, key_equal(), allocator_type())
{ _M_ht.insert_equal(__f, __l); }
template<class _InputIterator>
hash_multimap(_InputIterator __f, _InputIterator __l, size_type __n,
const hasher& __hf, const key_equal& __eql,
const allocator_type& __a = allocator_type())
: _M_ht(__n, __hf, __eql, __a)
{ _M_ht.insert_equal(__f, __l); }
size_type
size() const
{ return _M_ht.size(); }
size_type
max_size() const
{ return _M_ht.max_size(); }
_GLIBCXX_NODISCARD bool
empty() const
{ return _M_ht.empty(); }
void
swap(hash_multimap& __hs)
{ _M_ht.swap(__hs._M_ht); }
template<class _K1, class _T1, class _HF, class _EqK, class _Al>
friend bool
operator==(const hash_multimap<_K1, _T1, _HF, _EqK, _Al>&,
const hash_multimap<_K1, _T1, _HF, _EqK, _Al>&);
iterator
begin()
{ return _M_ht.begin(); }
iterator
end()
{ return _M_ht.end(); }
const_iterator
begin() const
{ return _M_ht.begin(); }
const_iterator
end() const
{ return _M_ht.end(); }
iterator
insert(const value_type& __obj)
{ return _M_ht.insert_equal(__obj); }
template<class _InputIterator>
void
insert(_InputIterator __f, _InputIterator __l)
{ _M_ht.insert_equal(__f,__l); }
iterator
insert_noresize(const value_type& __obj)
{ return _M_ht.insert_equal_noresize(__obj); }
iterator
find(const key_type& __key)
{ return _M_ht.find(__key); }
const_iterator
find(const key_type& __key) const
{ return _M_ht.find(__key); }
size_type
count(const key_type& __key) const
{ return _M_ht.count(__key); }
pair<iterator, iterator>
equal_range(const key_type& __key)
{ return _M_ht.equal_range(__key); }
pair<const_iterator, const_iterator>
equal_range(const key_type& __key) const
{ return _M_ht.equal_range(__key); }
size_type
erase(const key_type& __key)
{ return _M_ht.erase(__key); }
void
erase(iterator __it)
{ _M_ht.erase(__it); }
void
erase(iterator __f, iterator __l)
{ _M_ht.erase(__f, __l); }
void
clear()
{ _M_ht.clear(); }
void
resize(size_type __hint)
{ _M_ht.resize(__hint); }
size_type
bucket_count() const
{ return _M_ht.bucket_count(); }
size_type
max_bucket_count() const
{ return _M_ht.max_bucket_count(); }
size_type
elems_in_bucket(size_type __n) const
{ return _M_ht.elems_in_bucket(__n); }
};
template<class _Key, class _Tp, class _HF, class _EqKey, class _Alloc>
inline bool
operator==(const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm1,
const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm2)
{ return __hm1._M_ht == __hm2._M_ht; }
template<class _Key, class _Tp, class _HF, class _EqKey, class _Alloc>
inline bool
operator!=(const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm1,
const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm2)
{ return !(__hm1 == __hm2); }
template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
inline void
swap(hash_multimap<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
hash_multimap<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
{ __hm1.swap(__hm2); }
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// Specialization of insert_iterator so that it will work for hash_map
// and hash_multimap.
template<class _Key, class _Tp, class _HashFn, class _EqKey, class _Alloc>
class insert_iterator<__gnu_cxx::hash_map<_Key, _Tp, _HashFn,
_EqKey, _Alloc> >
{
protected:
typedef __gnu_cxx::hash_map<_Key, _Tp, _HashFn, _EqKey, _Alloc>
_Container;
_Container* container;
public:
typedef _Container container_type;
typedef output_iterator_tag iterator_category;
typedef void value_type;
typedef void difference_type;
typedef void pointer;
typedef void reference;
insert_iterator(_Container& __x)
: container(&__x) {}
insert_iterator(_Container& __x, typename _Container::iterator)
: container(&__x) {}
insert_iterator<_Container>&
operator=(const typename _Container::value_type& __value)
{
container->insert(__value);
return *this;
}
insert_iterator<_Container>&
operator*()
{ return *this; }
insert_iterator<_Container>&
operator++() { return *this; }
insert_iterator<_Container>&
operator++(int)
{ return *this; }
};
template<class _Key, class _Tp, class _HashFn, class _EqKey, class _Alloc>
class insert_iterator<__gnu_cxx::hash_multimap<_Key, _Tp, _HashFn,
_EqKey, _Alloc> >
{
protected:
typedef __gnu_cxx::hash_multimap<_Key, _Tp, _HashFn, _EqKey, _Alloc>
_Container;
_Container* container;
typename _Container::iterator iter;
public:
typedef _Container container_type;
typedef output_iterator_tag iterator_category;
typedef void value_type;
typedef void difference_type;
typedef void pointer;
typedef void reference;
insert_iterator(_Container& __x)
: container(&__x) {}
insert_iterator(_Container& __x, typename _Container::iterator)
: container(&__x) {}
insert_iterator<_Container>&
operator=(const typename _Container::value_type& __value)
{
container->insert(__value);
return *this;
}
insert_iterator<_Container>&
operator*()
{ return *this; }
insert_iterator<_Container>&
operator++()
{ return *this; }
insert_iterator<_Container>&
operator++(int)
{ return *this; }
};
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif
concept_check.h
c++config.h
backward_warning.h
std::pair::pair
pair(_T1, _T2) -> pair< _T1, _T2 >
Two pairs are equal iff their members are equal.
std
ISO C++ entities toplevel namespace is std.
__gnu_cxx
GNU extensions for public use.
std::allocator
The standard allocator, as per C++03 [20.4.1].
Definition allocator.h:134
std::equal_to
One of the comparison functors.
Definition stl_function.h:374
std::insert_iterator
Turns assignment into insertion.
Definition bits/stl_iterator.h:885
std::insert_iterator::operator*
constexpr insert_iterator & operator*()
Simply returns *this.
Definition bits/stl_iterator.h:965
std::insert_iterator::container_type
_Container container_type
A nested typedef for the type of whatever container you used.
Definition bits/stl_iterator.h:897
std::insert_iterator::operator=
constexpr insert_iterator & operator=(const typename _Container::value_type &__value)
Definition bits/stl_iterator.h:945
std::insert_iterator::operator++
constexpr insert_iterator & operator++()
Simply returns *this. (This iterator does not move.).
Definition bits/stl_iterator.h:971
std::insert_iterator::insert_iterator
constexpr insert_iterator(_Container &__x, _Iter __i)
Definition bits/stl_iterator.h:908
std::pair
Struct holding two objects (or references) of arbitrary type.
Definition stl_pair.h:307
std::pair::second
_T2 second
The second member.
Definition stl_pair.h:312
std::iterator< output_iterator_tag, void, void, void, void >::iterator_category
output_iterator_tag iterator_category
Definition stl_iterator_base_types.h:132
std::iterator< output_iterator_tag, void, void, void, void >::pointer
void pointer
Definition stl_iterator_base_types.h:138
std::iterator< output_iterator_tag, void, void, void, void >::reference
void reference
Definition stl_iterator_base_types.h:140
std::iterator< output_iterator_tag, void, void, void, void >::value_type
void value_type
Definition stl_iterator_base_types.h:134
__gnu_cxx::hash_map
Definition hash_map:84
__gnu_cxx::hash_multimap
Definition hash_map:297
hashtable.h