libcxx/include/ext/hash_set

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_HASH_SET
#define _LIBCPP_HASH_SET

/*

    hash_set synopsis

namespace __gnu_cxx
{

template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
          class Alloc = allocator<Value>>
class hash_set
{
public:
    // types
    typedef Value                                                      key_type;
    typedef key_type                                                   value_type;
    typedef Hash                                                       hasher;
    typedef Pred                                                       key_equal;
    typedef Alloc                                                      allocator_type;
    typedef value_type&                                                reference;
    typedef const value_type&                                          const_reference;
    typedef typename allocator_traits<allocator_type>::pointer         pointer;
    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
    typedef typename allocator_traits<allocator_type>::size_type       size_type;
    typedef typename allocator_traits<allocator_type>::difference_type difference_type;

    typedef /unspecified/ iterator;
    typedef /unspecified/ const_iterator;

    explicit hash_set(size_type n = 193, const hasher& hf = hasher(),
                           const key_equal& eql = key_equal(),
                           const allocator_type& a = allocator_type());
    template <class InputIterator>
        hash_set(InputIterator f, InputIterator l,
                      size_type n = 193, const hasher& hf = hasher(),
                      const key_equal& eql = key_equal(),
                      const allocator_type& a = allocator_type());
    hash_set(const hash_set&);
    ~hash_set();
    hash_set& operator=(const hash_set&);

    allocator_type get_allocator() const;

    bool      empty() const;
    size_type size() const;
    size_type max_size() const;

    iterator       begin();
    iterator       end();
    const_iterator begin()  const;
    const_iterator end()    const;

    pair<iterator, bool> insert(const value_type& obj);
    template <class InputIterator>
        void insert(InputIterator first, InputIterator last);

    void erase(const_iterator position);
    size_type erase(const key_type& k);
    void erase(const_iterator first, const_iterator last);
    void clear();

    void swap(hash_set&);

    hasher hash_funct() const;
    key_equal key_eq() const;

    iterator       find(const key_type& k);
    const_iterator find(const key_type& k) const;
    size_type count(const key_type& k) const;
    pair<iterator, iterator>             equal_range(const key_type& k);
    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;

    size_type bucket_count() const;
    size_type max_bucket_count() const;

    size_type elems_in_bucket(size_type n) const;

    void resize(size_type n);
};

template <class Value, class Hash, class Pred, class Alloc>
    void swap(hash_set<Value, Hash, Pred, Alloc>& x,
              hash_set<Value, Hash, Pred, Alloc>& y);

template <class Value, class Hash, class Pred, class Alloc>
    bool
    operator==(const hash_set<Value, Hash, Pred, Alloc>& x,
               const hash_set<Value, Hash, Pred, Alloc>& y);

template <class Value, class Hash, class Pred, class Alloc>
    bool
    operator!=(const hash_set<Value, Hash, Pred, Alloc>& x,
               const hash_set<Value, Hash, Pred, Alloc>& y);

template <class Value, class Hash = hash<Value>, class Pred = equal_to<Value>,
          class Alloc = allocator<Value>>
class hash_multiset
{
public:
    // types
    typedef Value                                                      key_type;
    typedef key_type                                                   value_type;
    typedef Hash                                                       hasher;
    typedef Pred                                                       key_equal;
    typedef Alloc                                                      allocator_type;
    typedef value_type&                                                reference;
    typedef const value_type&                                          const_reference;
    typedef typename allocator_traits<allocator_type>::pointer         pointer;
    typedef typename allocator_traits<allocator_type>::const_pointer   const_pointer;
    typedef typename allocator_traits<allocator_type>::size_type       size_type;
    typedef typename allocator_traits<allocator_type>::difference_type difference_type;

    typedef /unspecified/ iterator;
    typedef /unspecified/ const_iterator;

    explicit hash_multiset(size_type n = 193, const hasher& hf = hasher(),
                           const key_equal& eql = key_equal(),
                           const allocator_type& a = allocator_type());
    template <class InputIterator>
        hash_multiset(InputIterator f, InputIterator l,
                      size_type n = 193, const hasher& hf = hasher(),
                      const key_equal& eql = key_equal(),
                      const allocator_type& a = allocator_type());
    hash_multiset(const hash_multiset&);
    ~hash_multiset();
    hash_multiset& operator=(const hash_multiset&);

    allocator_type get_allocator() const;

    bool      empty() const;
    size_type size() const;
    size_type max_size() const;

    iterator       begin();
    iterator       end();
    const_iterator begin()  const;
    const_iterator end()    const;

    iterator insert(const value_type& obj);
    template <class InputIterator>
        void insert(InputIterator first, InputIterator last);

    void erase(const_iterator position);
    size_type erase(const key_type& k);
    void erase(const_iterator first, const_iterator last);
    void clear();

    void swap(hash_multiset&);

    hasher hash_funct() const;
    key_equal key_eq() const;

    iterator       find(const key_type& k);
    const_iterator find(const key_type& k) const;
    size_type count(const key_type& k) const;
    pair<iterator, iterator>             equal_range(const key_type& k);
    pair<const_iterator, const_iterator> equal_range(const key_type& k) const;

    size_type bucket_count() const;
    size_type max_bucket_count() const;

    size_type elems_in_bucket(size_type n) const;

    void resize(size_type n);
};

template <class Value, class Hash, class Pred, class Alloc>
    void swap(hash_multiset<Value, Hash, Pred, Alloc>& x,
              hash_multiset<Value, Hash, Pred, Alloc>& y);

template <class Value, class Hash, class Pred, class Alloc>
    bool
    operator==(const hash_multiset<Value, Hash, Pred, Alloc>& x,
               const hash_multiset<Value, Hash, Pred, Alloc>& y);

template <class Value, class Hash, class Pred, class Alloc>
    bool
    operator!=(const hash_multiset<Value, Hash, Pred, Alloc>& x,
               const hash_multiset<Value, Hash, Pred, Alloc>& y);
}  // __gnu_cxx

*/

#include <__config>
#include <__hash_table>
#include <algorithm>
#include <ext/__hash>
#include <functional>

#if defined(__DEPRECATED) && __DEPRECATED
#  if defined(_LIBCPP_WARNING)
_LIBCPP_WARNING("Use of the header <ext/hash_set> is deprecated.  Migrate to <unordered_set>")
#  else
#    warning Use of the header <ext/hash_set> is deprecated.  Migrate to <unordered_set>
#  endif
#endif

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

namespace __gnu_cxx {

template <class _Value,
          class _Hash  = hash<_Value>,
          class _Pred  = std::equal_to<_Value>,
          class _Alloc = std::allocator<_Value> >
class _LIBCPP_TEMPLATE_VIS hash_set {
public:
  // types
  typedef _Value key_type;
  typedef key_type value_type;
  typedef _Hash hasher;
  typedef _Pred key_equal;
  typedef _Alloc allocator_type;
  typedef value_type& reference;
  typedef const value_type& const_reference;

private:
  typedef std::__hash_table<value_type, hasher, key_equal, allocator_type> __table;

  __table __table_;

public:
  typedef typename __table::pointer pointer;
  typedef typename __table::const_pointer const_pointer;
  typedef typename __table::size_type size_type;
  typedef typename __table::difference_type difference_type;

  typedef typename __table::const_iterator iterator;
  typedef typename __table::const_iterator const_iterator;

  _LIBCPP_HIDE_FROM_ABI hash_set() {}
  _LIBCPP_HIDE_FROM_ABI explicit hash_set(
      size_type __n, const hasher& __hf = hasher(), const key_equal& __eql = key_equal());
  _LIBCPP_HIDE_FROM_ABI hash_set(size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a);
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI hash_set(_InputIterator __first, _InputIterator __last);
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI
  hash_set(_InputIterator __first,
           _InputIterator __last,
           size_type __n,
           const hasher& __hf     = hasher(),
           const key_equal& __eql = key_equal());
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI
  hash_set(_InputIterator __first,
           _InputIterator __last,
           size_type __n,
           const hasher& __hf,
           const key_equal& __eql,
           const allocator_type& __a);
  _LIBCPP_HIDE_FROM_ABI hash_set(const hash_set& __u);

  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const { return allocator_type(__table_.__node_alloc()); }

  _LIBCPP_HIDE_FROM_ABI bool empty() const { return __table_.size() == 0; }
  _LIBCPP_HIDE_FROM_ABI size_type size() const { return __table_.size(); }
  _LIBCPP_HIDE_FROM_ABI size_type max_size() const { return __table_.max_size(); }

  _LIBCPP_HIDE_FROM_ABI iterator begin() { return __table_.begin(); }
  _LIBCPP_HIDE_FROM_ABI iterator end() { return __table_.end(); }
  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const { return __table_.begin(); }
  _LIBCPP_HIDE_FROM_ABI const_iterator end() const { return __table_.end(); }

  _LIBCPP_HIDE_FROM_ABI std::pair<iterator, bool> insert(const value_type& __x) {
    return __table_.__insert_unique(__x);
  }
  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, const value_type& __x) { return insert(__x).first; }
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __first, _InputIterator __last);

  _LIBCPP_HIDE_FROM_ABI void erase(const_iterator __p) { __table_.erase(__p); }
  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __table_.__erase_unique(__k); }
  _LIBCPP_HIDE_FROM_ABI void erase(const_iterator __first, const_iterator __last) { __table_.erase(__first, __last); }
  _LIBCPP_HIDE_FROM_ABI void clear() { __table_.clear(); }

  _LIBCPP_HIDE_FROM_ABI void swap(hash_set& __u) { __table_.swap(__u.__table_); }

  _LIBCPP_HIDE_FROM_ABI hasher hash_funct() const { return __table_.hash_function(); }
  _LIBCPP_HIDE_FROM_ABI key_equal key_eq() const { return __table_.key_eq(); }

  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __table_.find(__k); }
  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __table_.find(__k); }
  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __table_.__count_unique(__k); }
  _LIBCPP_HIDE_FROM_ABI std::pair<iterator, iterator> equal_range(const key_type& __k) {
    return __table_.__equal_range_unique(__k);
  }
  _LIBCPP_HIDE_FROM_ABI std::pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
    return __table_.__equal_range_unique(__k);
  }

  _LIBCPP_HIDE_FROM_ABI size_type bucket_count() const { return __table_.bucket_count(); }
  _LIBCPP_HIDE_FROM_ABI size_type max_bucket_count() const { return __table_.max_bucket_count(); }

  _LIBCPP_HIDE_FROM_ABI size_type elems_in_bucket(size_type __n) const { return __table_.bucket_size(__n); }

  _LIBCPP_HIDE_FROM_ABI void resize(size_type __n) { __table_.__rehash_unique(__n); }
};

template <class _Value, class _Hash, class _Pred, class _Alloc>
hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(size_type __n, const hasher& __hf, const key_equal& __eql)
    : __table_(__hf, __eql) {
  __table_.__rehash_unique(__n);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
    size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
    : __table_(__hf, __eql, __a) {
  __table_.__rehash_unique(__n);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(_InputIterator __first, _InputIterator __last) {
  insert(__first, __last);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
    _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const key_equal& __eql)
    : __table_(__hf, __eql) {
  __table_.__rehash_unique(__n);
  insert(__first, __last);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(
    _InputIterator __first,
    _InputIterator __last,
    size_type __n,
    const hasher& __hf,
    const key_equal& __eql,
    const allocator_type& __a)
    : __table_(__hf, __eql, __a) {
  __table_.__rehash_unique(__n);
  insert(__first, __last);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
hash_set<_Value, _Hash, _Pred, _Alloc>::hash_set(const hash_set& __u) : __table_(__u.__table_) {
  __table_.__rehash_unique(__u.bucket_count());
  insert(__u.begin(), __u.end());
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
inline void hash_set<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first, _InputIterator __last) {
  for (; __first != __last; ++__first)
    __table_.__insert_unique(*__first);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
inline _LIBCPP_HIDE_FROM_ABI void
swap(hash_set<_Value, _Hash, _Pred, _Alloc>& __x, hash_set<_Value, _Hash, _Pred, _Alloc>& __y) {
  __x.swap(__y);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
_LIBCPP_HIDE_FROM_ABI bool
operator==(const hash_set<_Value, _Hash, _Pred, _Alloc>& __x, const hash_set<_Value, _Hash, _Pred, _Alloc>& __y) {
  if (__x.size() != __y.size())
    return false;
  typedef typename hash_set<_Value, _Hash, _Pred, _Alloc>::const_iterator const_iterator;
  for (const_iterator __i = __x.begin(), __ex = __x.end(), __ey = __y.end(); __i != __ex; ++__i) {
    const_iterator __j = __y.find(*__i);
    if (__j == __ey || !(*__i == *__j))
      return false;
  }
  return true;
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
inline _LIBCPP_HIDE_FROM_ABI bool
operator!=(const hash_set<_Value, _Hash, _Pred, _Alloc>& __x, const hash_set<_Value, _Hash, _Pred, _Alloc>& __y) {
  return !(__x == __y);
}

template <class _Value,
          class _Hash  = hash<_Value>,
          class _Pred  = std::equal_to<_Value>,
          class _Alloc = std::allocator<_Value> >
class _LIBCPP_TEMPLATE_VIS hash_multiset {
public:
  // types
  typedef _Value key_type;
  typedef key_type value_type;
  typedef _Hash hasher;
  typedef _Pred key_equal;
  typedef _Alloc allocator_type;
  typedef value_type& reference;
  typedef const value_type& const_reference;

private:
  typedef std::__hash_table<value_type, hasher, key_equal, allocator_type> __table;

  __table __table_;

public:
  typedef typename __table::pointer pointer;
  typedef typename __table::const_pointer const_pointer;
  typedef typename __table::size_type size_type;
  typedef typename __table::difference_type difference_type;

  typedef typename __table::const_iterator iterator;
  typedef typename __table::const_iterator const_iterator;

  _LIBCPP_HIDE_FROM_ABI hash_multiset() {}
  explicit _LIBCPP_HIDE_FROM_ABI
  hash_multiset(size_type __n, const hasher& __hf = hasher(), const key_equal& __eql = key_equal());
  _LIBCPP_HIDE_FROM_ABI
  hash_multiset(size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a);
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI hash_multiset(_InputIterator __first, _InputIterator __last);
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI
  hash_multiset(_InputIterator __first,
                _InputIterator __last,
                size_type __n,
                const hasher& __hf     = hasher(),
                const key_equal& __eql = key_equal());
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI hash_multiset(
      _InputIterator __first,
      _InputIterator __last,
      size_type __n,
      const hasher& __hf,
      const key_equal& __eql,
      const allocator_type& __a);
  _LIBCPP_HIDE_FROM_ABI hash_multiset(const hash_multiset& __u);

  _LIBCPP_HIDE_FROM_ABI allocator_type get_allocator() const { return allocator_type(__table_.__node_alloc()); }

  _LIBCPP_HIDE_FROM_ABI bool empty() const { return __table_.size() == 0; }
  _LIBCPP_HIDE_FROM_ABI size_type size() const { return __table_.size(); }
  _LIBCPP_HIDE_FROM_ABI size_type max_size() const { return __table_.max_size(); }

  _LIBCPP_HIDE_FROM_ABI iterator begin() { return __table_.begin(); }
  _LIBCPP_HIDE_FROM_ABI iterator end() { return __table_.end(); }
  _LIBCPP_HIDE_FROM_ABI const_iterator begin() const { return __table_.begin(); }
  _LIBCPP_HIDE_FROM_ABI const_iterator end() const { return __table_.end(); }

  _LIBCPP_HIDE_FROM_ABI iterator insert(const value_type& __x) { return __table_.__insert_multi(__x); }
  _LIBCPP_HIDE_FROM_ABI iterator insert(const_iterator, const value_type& __x) { return insert(__x); }
  template <class _InputIterator>
  _LIBCPP_HIDE_FROM_ABI void insert(_InputIterator __first, _InputIterator __last);

  _LIBCPP_HIDE_FROM_ABI void erase(const_iterator __p) { __table_.erase(__p); }
  _LIBCPP_HIDE_FROM_ABI size_type erase(const key_type& __k) { return __table_.__erase_multi(__k); }
  _LIBCPP_HIDE_FROM_ABI void erase(const_iterator __first, const_iterator __last) { __table_.erase(__first, __last); }
  _LIBCPP_HIDE_FROM_ABI void clear() { __table_.clear(); }

  _LIBCPP_HIDE_FROM_ABI void swap(hash_multiset& __u) { __table_.swap(__u.__table_); }

  _LIBCPP_HIDE_FROM_ABI hasher hash_funct() const { return __table_.hash_function(); }
  _LIBCPP_HIDE_FROM_ABI key_equal key_eq() const { return __table_.key_eq(); }

  _LIBCPP_HIDE_FROM_ABI iterator find(const key_type& __k) { return __table_.find(__k); }
  _LIBCPP_HIDE_FROM_ABI const_iterator find(const key_type& __k) const { return __table_.find(__k); }
  _LIBCPP_HIDE_FROM_ABI size_type count(const key_type& __k) const { return __table_.__count_multi(__k); }
  _LIBCPP_HIDE_FROM_ABI std::pair<iterator, iterator> equal_range(const key_type& __k) {
    return __table_.__equal_range_multi(__k);
  }
  _LIBCPP_HIDE_FROM_ABI std::pair<const_iterator, const_iterator> equal_range(const key_type& __k) const {
    return __table_.__equal_range_multi(__k);
  }

  _LIBCPP_HIDE_FROM_ABI size_type bucket_count() const { return __table_.bucket_count(); }
  _LIBCPP_HIDE_FROM_ABI size_type max_bucket_count() const { return __table_.max_bucket_count(); }

  _LIBCPP_HIDE_FROM_ABI size_type elems_in_bucket(size_type __n) const { return __table_.bucket_size(__n); }

  _LIBCPP_HIDE_FROM_ABI void resize(size_type __n) { __table_.__rehash_multi(__n); }
};

template <class _Value, class _Hash, class _Pred, class _Alloc>
hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(size_type __n, const hasher& __hf, const key_equal& __eql)
    : __table_(__hf, __eql) {
  __table_.__rehash_multi(__n);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
    size_type __n, const hasher& __hf, const key_equal& __eql, const allocator_type& __a)
    : __table_(__hf, __eql, __a) {
  __table_.__rehash_multi(__n);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(_InputIterator __first, _InputIterator __last) {
  insert(__first, __last);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
    _InputIterator __first, _InputIterator __last, size_type __n, const hasher& __hf, const key_equal& __eql)
    : __table_(__hf, __eql) {
  __table_.__rehash_multi(__n);
  insert(__first, __last);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(
    _InputIterator __first,
    _InputIterator __last,
    size_type __n,
    const hasher& __hf,
    const key_equal& __eql,
    const allocator_type& __a)
    : __table_(__hf, __eql, __a) {
  __table_.__rehash_multi(__n);
  insert(__first, __last);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
hash_multiset<_Value, _Hash, _Pred, _Alloc>::hash_multiset(const hash_multiset& __u) : __table_(__u.__table_) {
  __table_.__rehash_multi(__u.bucket_count());
  insert(__u.begin(), __u.end());
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
template <class _InputIterator>
inline void hash_multiset<_Value, _Hash, _Pred, _Alloc>::insert(_InputIterator __first, _InputIterator __last) {
  for (; __first != __last; ++__first)
    __table_.__insert_multi(*__first);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
inline _LIBCPP_HIDE_FROM_ABI void
swap(hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x, hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y) {
  __x.swap(__y);
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
_LIBCPP_HIDE_FROM_ABI bool operator==(const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
                                      const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y) {
  if (__x.size() != __y.size())
    return false;
  typedef typename hash_multiset<_Value, _Hash, _Pred, _Alloc>::const_iterator const_iterator;
  typedef std::pair<const_iterator, const_iterator> _EqRng;
  for (const_iterator __i = __x.begin(), __ex = __x.end(); __i != __ex;) {
    _EqRng __xeq = __x.equal_range(*__i);
    _EqRng __yeq = __y.equal_range(*__i);
    if (std::distance(__xeq.first, __xeq.second) != std::distance(__yeq.first, __yeq.second) ||
        !std::is_permutation(__xeq.first, __xeq.second, __yeq.first))
      return false;
    __i = __xeq.second;
  }
  return true;
}

template <class _Value, class _Hash, class _Pred, class _Alloc>
inline _LIBCPP_HIDE_FROM_ABI bool operator!=(const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __x,
                                             const hash_multiset<_Value, _Hash, _Pred, _Alloc>& __y) {
  return !(__x == __y);
}

} // namespace __gnu_cxx

#if !defined(_LIBCPP_REMOVE_TRANSITIVE_INCLUDES) && _LIBCPP_STD_VER <= 20
#  include <concepts>
#  include <iterator>
#  include <type_traits>
#endif

#endif // _LIBCPP_HASH_SET