unordered_set

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// <unordered_set> -*- C++ -*-

// Copyright (C) 2007-2026 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/>.

/** @file include/unordered_set
 *  This is a Standard C++ Library header.
 */

#ifndef _GLIBCXX_UNORDERED_SET
#define _GLIBCXX_UNORDERED_SET 1

#ifdef _GLIBCXX_SYSHDR
#pragma GCC system_header
#endif

#include <bits/requires_hosted.h> // containers

#if __cplusplus < 201103L
# include <bits/c++0x_warning.h>
#else

#include <initializer_list>
#include <bits/unordered_set.h>
#include <bits/range_access.h>
#include <bits/erase_if.h>

#ifdef _GLIBCXX_DEBUG
# include <debug/unordered_set>
#endif

#define __glibcxx_want_allocator_traits_is_always_equal
#define __glibcxx_want_containers_ranges
#define __glibcxx_want_erase_if
#define __glibcxx_want_generic_unordered_lookup
#define __glibcxx_want_node_extract
#define __glibcxx_want_nonmember_container_access
#define __glibcxx_want_associative_heterogeneous_erasure
#define __glibcxx_want_associative_heterogeneous_insertion
#include <bits/version.h>

#if __cplusplus >= 201703L
#include <bits/memory_resource.h>
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
  namespace pmr
  {
    template<typename _Key, typename _Hash = std::hash<_Key>,
             typename _Pred = std::equal_to<_Key>>
      using unordered_set
        = std::unordered_set<_Key, _Hash, _Pred,
                             polymorphic_allocator<_Key>>;
    template<typename _Key, typename _Hash = std::hash<_Key>,
             typename _Pred = std::equal_to<_Key>>
      using unordered_multiset
        = std::unordered_multiset<_Key, _Hash, _Pred,
                                  polymorphic_allocator<_Key>>;
  } // namespace pmr
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // C++17

#ifdef __cpp_lib_erase_if // C++ >= 20 && HOSTED
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
  template<typename _Key, typename _Hash, typename _CPred, typename _Alloc,
           typename _Predicate>
    inline typename _GLIBCXX_STD_C::unordered_set<_Key, _Hash,
                                                  _CPred, _Alloc>::size_type
    erase_if(_GLIBCXX_STD_C::unordered_set<_Key, _Hash, _CPred, _Alloc>& __cont,
             _Predicate __pred)
    { return __detail::__erase_nodes_if(__cont, __cont, __pred); }

  template<typename _Key, typename _Hash, typename _CPred, typename _Alloc,
           typename _Predicate>
    inline typename _GLIBCXX_STD_C::unordered_multiset<_Key, _Hash,
                                                      _CPred, _Alloc>::size_type
    erase_if(_GLIBCXX_STD_C::unordered_multiset<_Key, _Hash, _CPred, _Alloc>& __cont,
             _Predicate __pred)
    { return __detail::__erase_nodes_if(__cont, __cont, __pred); }
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace std
#endif // __cpp_lib_erase_if

#endif // C++11

#endif // _GLIBCXX_UNORDERED_SET