// <forward_list> -*- C++ -*-

// Copyright (C) 2010-2022 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/forward_list
 *  This file is a GNU debug extension to the Standard C++ Library.
 */

#ifndef _GLIBCXX_DEBUG_FORWARD_LIST
#define _GLIBCXX_DEBUG_FORWARD_LIST 1

#pragma GCC system_header

#include <bits/c++config.h>
namespace std _GLIBCXX_VISIBILITY(default) { namespace __debug {
  template<typename _Tp, typename _Allocator> class forward_list;
} } // namespace std::__debug

#include <forward_list>
#include <debug/safe_sequence.h>
#include <debug/safe_container.h>
#include <debug/safe_iterator.h>

// Special validity check for forward_list ranges.
#define __glibcxx_check_valid_fl_range(_First,_Last,_Dist)		\
_GLIBCXX_DEBUG_VERIFY(_First._M_valid_range(_Last, _Dist, false),	\
		      _M_message(__gnu_debug::__msg_valid_range)	\
		      ._M_iterator(_First, #_First)			\
		      ._M_iterator(_Last, #_Last))

namespace __gnu_debug
{
  /// Special iterators swap and invalidation for forward_list because of the
  /// before_begin iterator.
  template<typename _SafeSequence>
    class _Safe_forward_list
    : public _Safe_sequence<_SafeSequence>
    {
      _SafeSequence&
      _M_this() noexcept
      { return *static_cast<_SafeSequence*>(this); }

      static void
      _M_swap_aux(_Safe_sequence_base& __lhs,
		  _Safe_iterator_base*& __lhs_iterators,
		  _Safe_sequence_base& __rhs,
		  _Safe_iterator_base*& __rhs_iterators);

      void _M_swap_single(_Safe_sequence_base&) noexcept;

    protected:
      void
      _M_invalidate_all()
      {
	using _Base_const_iterator = __decltype(_M_this()._M_base().cend());
	this->_M_invalidate_if([this](_Base_const_iterator __it)
	{
	  return __it != _M_this()._M_base().cbefore_begin()
	    && __it != _M_this()._M_base().cend(); });
      }

      void _M_swap(_Safe_sequence_base&) noexcept;
    };

   template<typename _SafeSequence>
    void
    _Safe_forward_list<_SafeSequence>::
    _M_swap_aux(_Safe_sequence_base& __lhs,
		_Safe_iterator_base*& __lhs_iterators,
		_Safe_sequence_base& __rhs,
		_Safe_iterator_base*& __rhs_iterators)
    {
      using const_iterator = typename _SafeSequence::const_iterator;
      _Safe_iterator_base* __bbegin_its = 0;
      _Safe_iterator_base* __last_bbegin = 0;
      _SafeSequence& __rseq = static_cast<_SafeSequence&>(__rhs);

      for (_Safe_iterator_base* __iter = __lhs_iterators; __iter;)
	{
	  // Even iterator is cast to const_iterator, not a problem.
	  _Safe_iterator_base* __victim_base = __iter;
	  const_iterator* __victim =
	    static_cast<const_iterator*>(__victim_base)                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                             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