// Debugging multiset implementation -*- C++ -*-

// Copyright (C) 2003-2026 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 debug/multiset.h
 *  This file is a GNU debug extension to the Standard C++ Library.
 */

#ifndef _GLIBCXX_DEBUG_MULTISET_H
#define _GLIBCXX_DEBUG_MULTISET_H 1

#include <debug/safe_sequence.h>
#include <debug/safe_container.h>
#include <debug/safe_iterator.h>
#include <bits/stl_pair.h>

namespace std _GLIBCXX_VISIBILITY(default)
{
namespace __debug
{
  /// Class std::multiset with safety/checking/debug instrumentation.
  template<typename _Key, typename _Compare = std::less<_Key>,
	   typename _Allocator = std::allocator<_Key> >
    class multiset
    : public __gnu_debug::_Safe_container<
	multiset<_Key, _Compare, _Allocator>, _Allocator,
	__gnu_debug::_Safe_node_sequence>,
      public _GLIBCXX_STD_C::multiset<_Key, _Compare, _Allocator>
    {
      typedef _GLIBCXX_STD_C::multiset<_Key, _Compare, _Allocator>	_Base;
      typedef __gnu_debug::_Safe_container<
	multiset, _Allocator, __gnu_debug::_Safe_node_sequence>		_Safe;

      typedef typename _Base::const_iterator	_Base_const_iterator;
      typedef typename _Base::iterator		_Base_iterator;
      typedef __gnu_debug::_Equal_to<_Base_const_iterator> _Equal;

      template<typename _ItT, typename _SeqT, typename _CatT>
	friend class ::__gnu_debug::_Safe_iterator;

      // Reference wrapper for base class. Disambiguates multiset(const _Base&)
      // from copy constructor by requiring a user-defined conversion.
      // See PR libstdc++/90102.
      struct _Base_ref
      {
	_Base_ref(const _Base& __r) : _M_ref(__r) { }

	const _Base& _M_ref;
      };

    public:
      // types:
      typedef _Key					key_type;
      typedef _Key					value_type;
      typedef _Compare					key_compare;
      typedef _Compare					value_compare;
      typedef _Allocator				allocator_type;
      typedef typename _Base::reference			reference;
      typedef typename _Base::const_reference		const_reference;

      typedef __gnu_debug::_Safe_iterator<_Base_iterator, multiset>
							iterator;
      typedef __gnu_debug::_Safe_iterator<_Base_const_iterator,
					  multiset>	const_iterator;

      typedef typename _Base::size_type			size_type;
      typedef typename _Base::difference_type		difference_type;
      typedef typename _Base::pointer			pointer;
      typedef typename _Base::const_pointer		const_pointer;
      typedef std::reverse_iterator<iterator>		reverse_iterator;
      typedef std::reverse_iterator<const_iterator>	const_reverse_iterator;

      // 23.3.3.1 construct/copy/destroy:

#if __cplusplus < 201103L
      multiset() : _Base() { }

      multiset(const multiset& __x)
      : _Base(__x) { }

      ~multiset() { }
#else
      multiset() = default;
      multiset(const multiset&) = default;
      multiset(multiset&&) = default;

      multiset(initializer_list<value_type> __l,
	       const _Compare& __comp = _Compare(),
	       const allocator_type& __a = allocator_type())
      : _Base(__l, __comp, __a) { }

      explicit
      multiset(const allocator_type& __a)
      : _Base(__a) { }

      multiset(const multiset& __m,
	       const __type_identity_t<allocator_type>& __a)
      : _Base(__m, __a) { }

      multiset(multiset&& __m, const __type_identity_t<allocator_type>& __a)
      noexcept( noexcept(_Base(std::move(__m), __a)) )
      : _Safe(std::move(__m), __a),
	_Base(std::move(__m), __a) { }

      multiset(initializer_list<value_type> __l, const allocator_type& __a)
	: _Base(__l, __a)
      { }

      template<typename _InputIterator>
	multiset(_InputIterator __first, _InputIterator __last,
		 const allocator_type& __a)
	: _Base(__gnu_debug::__base(
		  __glibcxx_check_valid_constructor_range(__first, __last)),
		__gnu_debug::__base(__last), __a) { }

#if __glibcxx_containers_ranges // C++ >= 23
      /**
       * @brief Construct a multiset from a range.
       * @since C++23
       */
      template<std::__detail::__container_compatible_range<value_type> _Rg>
	multiset(std::from_range_t __t, _Rg&& __rg,
		 const _Compare& __c,
		 const allocator_type& __a = allocator_type())
	: _Base(__t, std::forward<_Rg>(__rg), __c, __a)
	{ }

      template<std::__detail::__container_compatible_range<value_type> _Rg>
	multiset(std::from_range_t __t, _Rg&& __rg,
		 const allocator_type& __a = allocator_type())
	: _Base(__t, std::forward<_Rg>(__rg), __a)
	{ }
#endif

      ~multiset() = default;
#endif

      explicit multiset(const _Compare& __comp,
			const _Allocator& __a = _Allocator())
      : _Base(__comp, __a) { }

      template<typename _InputIterator>
	multiset(_InputIterator __first, _InputIterator __last,
		 const _Compare& __comp = _Compare(),
		 const _Allocator& __a = _Allocator())
	: _Base(__gnu_debug::__base(
		  __glibcxx_check_valid_constructor_range(__first, __last)),
		__gnu_debug::__base(__last),
		__comp, __a) { }

      multiset(_Base_ref __x)
      : _Base(__x._M_ref) { }

#if __cplusplus >= 201103L
      multiset&
      operator=(const multiset&) = default;

      multiset&
      operator=(multiset&&) = default;

      multiset&
      operator=(initializer_list<value_type> __l)
      {
	_Base::operator=(__l);
	this->_M_invalidate_all();
	return *this;
      }
#endif

      using _Base::get_allocator;

      // iterators:
      iterator
      begin() _GLIBCXX_NOEXCEPT
      { return iterator(_Base::begin(), this); }

      const_iterator
      begin() const _GLIBCXX_NOEXCEPT
      { return const_iterator(_Base::begin(), this); }

      iterator
      end() _GLIBCXX_NOEXCEPT
      { return iterator(_Base::end(), this); }

      const_iterator
      end() const _GLIBCXX_NOEXCEPT
      { return const_iterator(_Base::end(), this); }

      reverse_iterator
      rbegin() _GLIBCXX_NOEXCEPT
      { return reverse_iterator(end()); }

      const_reverse_iterator
      rbegin() const _GLIBCXX_NOEXCEPT
      { return const_reverse_iterator(end()); }

      reverse_iterator
      rend() _GLIBCXX_NOEXCEPT
      { return reverse_iterator(begin()); }

      const_reverse_iterator
      rend() const _GLIBCXX_NOEXCEPT
      { return const_reverse_iterator(begin()); }

#if __cplusplus >= 201103L
      const_iterator
      cbegin() const noexcept
      { return const_iterator(_Base::begin(), this); }

      const_iterator
      cend() const noexcept
      { return const_iterator(_Base::end(), this); }

      const_reverse_iterator
      crbegin() const noexcept
      { return const_reverse_iterator(end()); }

      const_reverse_iterator
      crend() const noexcept
      { return const_reverse_iterator(begin()); }
#endif

      // capacity:
      using _Base::empty;
      using _Base::size;
      using _Base::max_size;

      // modifiers:
#if __cplusplus >= 201103L
      template<typename... _Args>
	iterator
	emplace(_Args&&... __args)
	{ return { _Base::emplace(std::forward<_Args>(__args)...), this }; }

      template<typename... _Args>
	iterator
	emplace_hint(const_iterator __pos, _Args&&... __args)
	{
	  __glibcxx_check_insert(__pos);
	  return
	    {
	      _Base::emplace_hint(__pos.base(), std::forward<_Args>(__args)...),
	      this
	    };
	}
#endif

      iterator
      insert(const value_type& __x)
      { return iterator(_Base::insert(__x), this); }

#if __cplusplus >= 201103L
      iterator
      insert(value_type&& __x)
      { return { _Base::insert(std::move(__x)), this }; }
#endif

      iterator
      insert(const_iterator __position, const value_type& __x)
      {
	__glibcxx_check_insert(__position);
	return iterator(_Base::insert(__position.base(), __x), this);
      }

#if __cplusplus >= 201103L
      iterator
      insert(const_iterator __position, value_type&& __x)
      {
	__glibcxx_check_insert(__position);
	return { _Base::insert(__position.base(), std::move(__x)), this };
      }
#endif

      template<typename _InputIterator>
	void
	insert(_InputIterator __first, _InputIterator __last)
	{
	  typename __gnu_debug::_Distance_traits<_InputIterator>::__type __dist;
	  __glibcxx_check_valid_range2(__first, __last, __dist);

	  if (__dist.second >= __gnu_debug::__dp_sign)
	    _Base::insert(__gnu_debug::__unsafe(__first),
			  __gnu_debug::__unsafe(__last));
	  else
	    _Base::insert(__first, __last);
	}

#if __cplusplus >= 201103L
      void
      insert(initializer_list<value_type> __l)
      { _Base::insert(__l); }
#endif

#ifdef __glibcxx_node_extract // >= C++17 && HOSTED
      using node_type = typename _Base::node_type;

      node_type
      extract(const_iterator __position)
      {
	__glibcxx_check_erase(__position);
	this->_M_invalidate_if(_Equal(__position.base()));
	return _Base::extract(__position.base());
      }

      node_type
      extract(const key_type& __key)
      {
	const auto __position = find(__key);
	if (__position != end())
	  return extract(__position);
	return {};
      }

# ifdef __glibcxx_associative_heterogeneous_erasure
      template <__heterogeneous_tree_key<multiset> _Kt>
	node_type
	extract(_Kt&& __key)
	{
	  const auto __position = find(__key);
	  if (__position != end())
	    return extract(__position);
	  return {};
	}
#endif

      iterator
      insert(node_type&& __nh)
      { return { _Base::insert(std::move(__nh)), this }; }

      iterator
      insert(const_iterator __hint, node_type&& __nh)
      {
	__glibcxx_check_insert(__hint);
	return { _Base::insert(__hint.base(), std::move(__nh)), this };
      }

      using _Base::merge;
#endif // C++17

#if __cplusplus >= 201103L
      _GLIBCXX_ABI_TAG_CXX11
      iterator
      erase(const_iterator __position)
      {
	__glibcxx_check_erase(__position);
	return { erase(__position.base()), this };
      }

      _Base_iterator
      erase(_Base_const_iterator __position)
      {
	__glibcxx_check_erase2(__position);
	this->_M_invalidate_if(_Equal(__position));
	return _Base::erase(__position);
      }
#else
      void
      erase(iterator __position)
      {
	__glibcxx_check_erase(__position);
	this->_M_invalidate_if(_Equal(__position.base()));
	_Base::erase(__position.base());
      }
#endif

      size_type
      erase(const key_type& __x)
      {
	std::pair<_Base_iterator, _Base_iterator> __victims =
	  _Base::equal_range(__x);
	size_type __count = 0;
	_Base_iterator __victim = __victims.first;
	while (__victim != __victims.second)
	  {
	    this->_M_invalidate_if(_Equal(__victim));
	    _Base::erase(__victim++);
	    ++__count;
	  }
	return __count;
      }

# ifdef __glibcxx_associative_heterogeneous_erasure
      template <__heterogeneous_tree_key<multiset> _Kt>
	size_type
	erase(_Kt&& __x)
	{
	  auto __victims = _Base::equal_range(__x);
	  size_type __count = 0;
	  for (auto __victim = __victims.first; __victim != __victims.second;)
	    {
	      this->_M_invalidate_if(_Equal(__victim));
	      _Base::erase(__victim++);
	      ++__count;
	    }
	  return __count;
	}
# endif

#if __cplusplus >= 201103L
      _GLIBCXX_ABI_TAG_CXX11
      iterator
      erase(const_iterator __first, const_iterator __last)
      {
	// _GLIBCXX_RESOLVE_LIB_DEFECTS
	// 151. can't currently clear() empty container
	__glibcxx_check_erase_range(__first, __last);
	for (_Base_const_iterator __victim = __first.base();
	     __victim != __last.base(); ++__victim)
	  {
	    _GLIBCXX_DEBUG_VERIFY(__victim != _Base::cend(),
				  _M_message(__gnu_debug::__msg_valid_range)
				  ._M_iterator(__first, "first")
				  ._M_iterator(__last, "last"));
	    this->_M_invalidate_if(_Equal(__victim));
	  }

	return { _Base::erase(__first.base(), __last.base()), this };
      }
#else
      void
      erase(iterator __first, iterator __last)
      {
	// _GLIBCXX_RESOLVE_LIB_DEFECTS
	// 151. can't currently clear() empty container
	__glibcxx_check_erase_range(__first, __last);
	for (_Base_iterator __victim = __first.base();
	     __victim != __last.base(); ++__victim)
	  {
	    _GLIBCXX_DEBUG_VERIFY(__victim != _Base::end(),
				  _M_message(__gnu_debug::__msg_valid_range)
				  ._M_iterator(__first, "first")
				  ._M_iterator(__last, "last"));
	    this->_M_invalidate_if(_Equal(__victim));
	  }
	_Base::erase(__first.base(), __last.base());
      }
#endif

      void
      swap(multiset& __x)
      _GLIBCXX_NOEXCEPT_IF( noexcept(declval<_Base&>().swap(__x)) )
      {
	_Safe::_M_swap(__x);
	_Base::swap(__x);
      }

      void
      clear() _GLIBCXX_NOEXCEPT
      {
	this->_M_invalidate_all();
	_Base::clear();
      }

      // observers:
      using _Base::key_comp;
      using _Base::value_comp;

      // multiset operations:
      iterator
      find(const key_type& __x)
      { return iterator(_Base::find(__x), this); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 214. set::find() missing const overload
      const_iterator
      find(const key_type& __x) const
      { return const_iterator(_Base::find(__x), this); }

#ifdef __glibcxx_generic_associative_lookup // C++ >= 14
      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	iterator
	find(const _Kt& __x)
	{ return { _Base::find(__x), this }; }

      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	const_iterator
	find(const _Kt& __x) const
	{ return { _Base::find(__x), this }; }
#endif

      using _Base::count;

      iterator
      lower_bound(const key_type& __x)
      { return iterator(_Base::lower_bound(__x), this); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 214. set::find() missing const overload
      const_iterator
      lower_bound(const key_type& __x) const
      { return const_iterator(_Base::lower_bound(__x), this); }

#ifdef __glibcxx_generic_associative_lookup // C++ >= 14
      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	iterator
	lower_bound(const _Kt& __x)
	{ return { _Base::lower_bound(__x), this }; }

      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	const_iterator
	lower_bound(const _Kt& __x) const
	{ return { _Base::lower_bound(__x), this }; }
#endif

      iterator
      upper_bound(const key_type& __x)
      { return iterator(_Base::upper_bound(__x), this); }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 214. set::find() missing const overload
      const_iterator
      upper_bound(const key_type& __x) const
      { return const_iterator(_Base::upper_bound(__x), this); }

#ifdef __glibcxx_generic_associative_lookup // C++ >= 14
      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	iterator
	upper_bound(const _Kt& __x)
	{ return { _Base::upper_bound(__x), this }; }

      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	const_iterator
	upper_bound(const _Kt& __x) const
	{ return { _Base::upper_bound(__x), this }; }
#endif

      std::pair<iterator,iterator>
      equal_range(const key_type& __x)
      {
	std::pair<_Base_iterator, _Base_iterator> __res =
	  _Base::equal_range(__x);
	return std::make_pair(iterator(__res.first, this),
			      iterator(__res.second, this));
      }

      // _GLIBCXX_RESOLVE_LIB_DEFECTS
      // 214. set::find() missing const overload
      std::pair<const_iterator,const_iterator>
      equal_range(const key_type& __x) const
      {
	std::pair<_Base_const_iterator, _Base_const_iterator> __res =
	  _Base::equal_range(__x);
	return std::make_pair(const_iterator(__res.first, this),
			      const_iterator(__res.second, this));
      }

#ifdef __glibcxx_generic_associative_lookup // C++ >= 14
      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	std::pair<iterator, iterator>
	equal_range(const _Kt& __x)
	{
	  auto __res = _Base::equal_range(__x);
	  return { { __res.first, this }, { __res.second, this } };
	}

      template<typename _Kt,
	       typename _Req =
		 typename __has_is_transparent<_Compare, _Kt>::type>
	std::pair<const_iterator, const_iterator>
	equal_range(const _Kt& __x) const
	{
	  auto __res = _Base::equal_range(__x);
	  return { { __res.first, this }, { __res.second, this } };
	}
#endif

      _Base&
      _M_base() _GLIBCXX_NOEXCEPT { return *this; }

      const _Base&
      _M_base() const _GLIBCXX_NOEXCEPT { return *this; }
    };

#if __cpp_deduction_guides >= 201606

  template<typename _InputIterator,
	   typename _Compare =
	     less<typename iterator_traits<_InputIterator>::value_type>,
	   typename _Allocator =
	     allocator<typename iterator_traits<_InputIterator>::value_type>,
	   typename = _RequireInputIter<_InputIterator>,
	   typename = _RequireNotAllocator<_Compare>,
	   typename = _RequireAllocator<_Allocator>>
    multiset(_InputIterator, _InputIterator,
	     _Compare = _Compare(), _Allocator = _Allocator())
    -> multiset<typename iterator_traits<_InputIterator>::value_type,
		_Compare, _Allocator>;

  template<typename _Key,
	   typename _Compare = less<_Key>,
	   typename _Allocator = allocator<_Key>,
	   typename = _RequireNotAllocator<_Compare>,
	   typename = _RequireAllocator<_Allocator>>
    multiset(initializer_list<_Key>,
	     _Compare = _Compare(), _Allocator = _Allocator())
    -> multiset<_Key, _Compare, _Allocator>;

  template<typename _InputIterator, typename _Allocator,
	   typename = _RequireInputIter<_InputIterator>,
	   typename = _RequireAllocator<_Allocator>>
    multiset(_InputIterator, _InputIterator, _Allocator)
    -> multiset<typename iterator_traits<_InputIterator>::value_type,
		less<typename iterator_traits<_InputIterator>::value_type>,
		_Allocator>;

  template<typename _Key, typename _Allocator,
	   typename = _RequireAllocator<_Allocator>>
    multiset(initializer_list<_Key>, _Allocator)
    -> multiset<_Key, less<_Key>, _Allocator>;

#if __glibcxx_containers_ranges // C++ >= 23
  template<ranges::input_range _Rg,
	   __not_allocator_like _Compare = less<ranges::range_value_t<_Rg>>,
	   __allocator_like _Alloc = std::allocator<ranges::range_value_t<_Rg>>>
    multiset(from_range_t, _Rg&&, _Compare = _Compare(), _Alloc = _Alloc())
      -> multiset<ranges::range_value_t<_Rg>, _Compare, _Alloc>;

  template<ranges::input_range _Rg, __allocator_like _Alloc>
    multiset(from_range_t, _Rg&&, _Alloc)
      -> multiset<ranges::range_value_t<_Rg>, less<ranges::range_value_t<_Rg>>, _Alloc>;
#endif
#endif // deduction guides

  template<typename _Key, typename _Compare, typename _Allocator>
    inline bool
    operator==(const multiset<_Key, _Compare, _Allocator>& __lhs,
	       const multiset<_Key, _Compare, _Allocator>& __rhs)
    { return __lhs._M_base() == __rhs._M_base(); }

#if __cpp_lib_three_way_comparison
  template<typename _Key, typename _Compare, typename _Alloc>
    inline __detail::__synth3way_t<_Key>
    operator<=>(const multiset<_Key, _Compare, _Alloc>& __lhs,
		const multiset<_Key, _Compare, _Alloc>& __rhs)
    { return __lhs._M_base() <=> __rhs._M_base(); }
#else
  template<typename _Key, typename _Compare, typename _Allocator>
    inline bool
    operator!=(const multiset<_Key, _Compare, _Allocator>& __lhs,
	       const multiset<_Key, _Compare, _Allocator>& __rhs)
    { return __lhs._M_base() != __rhs._M_base(); }

  template<typename _Key, typename _Compare, typename _Allocator>
    inline bool
    operator<(const multiset<_Key, _Compare, _Allocator>& __lhs,
	      const multiset<_Key, _Compare, _Allocator>& __rhs)
    { return __lhs._M_base() < __rhs._M_base(); }

  template<typename _Key, typename _Compare, typename _Allocator>
    inline bool
    operator<=(const multiset<_Key, _Compare, _Allocator>& __lhs,
	       const multiset<_Key, _Compare, _Allocator>& __rhs)
    { return __lhs._M_base() <= __rhs._M_base(); }

  template<typename _Key, typename _Compare, typename _Allocator>
    inline bool
    operator>=(const multiset<_Key, _Compare, _Allocator>& __lhs,
	       const multiset<_Key, _Compare, _Allocator>& __rhs)
    { return __lhs._M_base() >= __rhs._M_base(); }

  template<typename _Key, typename _Compare, typename _Allocator>
    inline bool
    operator>(const multiset<_Key, _Compare, _Allocator>& __lhs,
	      const multiset<_Key, _Compare, _Allocator>& __rhs)
    { return __lhs._M_base() > __rhs._M_base(); }
#endif // three-way comparison

  template<typename _Key, typename _Compare, typename _Allocator>
    void
    swap(multiset<_Key, _Compare, _Allocator>& __x,
	 multiset<_Key, _Compare, _Allocator>& __y)
    _GLIBCXX_NOEXCEPT_IF(noexcept(__x.swap(__y)))
    { return __x.swap(__y); }

} // namespace __debug
} // namespace std

#endif