text: // -*- C++ -*-
  
  // Copyright (C) 2005-2021 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) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
  
  // Permission to use, copy, modify, sell, and distribute this software
  // is hereby granted without fee, provided that the above copyright
  // notice appears in all copies, and that both that copyright notice
  // and this permission notice appear in supporting documentation. None
  // of the above authors, nor IBM Haifa Research Laboratories, make any
  // representation about the suitability of this software for any
  // purpose. It is provided "as is" without express or implied
  // warranty.
  
  /**
   * @file splay_tree_/erase_fn_imps.hpp
   * Contains an implementation class for splay_tree_.
   */
  
  #ifdef PB_DS_CLASS_C_DEC
  
  PB_DS_CLASS_T_DEC
  inline bool
  PB_DS_CLASS_C_DEC::
  erase(key_const_reference r_key)
  {
    point_iterator it = find(r_key);
    if (it == base_type::end())
      return false;
    erase(it);
    return true;
  }
  
  PB_DS_CLASS_T_DEC
  inline typename PB_DS_CLASS_C_DEC::iterator
  PB_DS_CLASS_C_DEC::
  erase(iterator it)
  {
    PB_DS_ASSERT_VALID((*this))
    if (it == base_type::end())
      return it;
    iterator ret_it = it;
    ++ret_it;
    erase_node(it.m_p_nd);
    PB_DS_ASSERT_VALID((*this))
    return ret_it;
  }
  
  PB_DS_CLASS_T_DEC
  inline typename PB_DS_CLASS_C_DEC::reverse_iterator
  PB_DS_CLASS_C_DEC::
  erase(reverse_iterator it)
  {
    PB_DS_ASSERT_VALID((*this))
    if (it.m_p_nd == base_type::m_p_head)
      return (it);
    reverse_iterator ret_it = it;
    ++ret_it;
    erase_node(it.m_p_nd);
    PB_DS_ASSERT_VALID((*this))
    return ret_it;
  }
  
  PB_DS_CLASS_T_DEC
  template<typename Pred>
  inline typename PB_DS_CLASS_C_DEC::size_type
  PB_DS_CLASS_C_DEC::
  erase_if(Pred pred)
  {
    PB_DS_ASSERT_VALID((*this))
    size_type num_ersd = 0;
    iterator it = base_type::begin();
    while (it != base_type::end())
      {
        if (pred(*it))
          {
  	  ++num_ersd;
  	  it = erase(it);
          }
        else
  	++it;
      }
    PB_DS_ASSERT_VALID((*this))
    return num_ersd;
  }
  
  PB_DS_CLASS_T_DEC
  void
  PB_DS_CLASS_C_DEC::
  erase_node(node_pointer p_nd)
  {
    _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
    splay(p_nd);
  
    PB_DS_ASSERT_VALID((*this))
    _GLIBCXX_DEBUG_ASSERT(p_nd == this->m_p_head->m_p_parent);
  
    node_pointer p_l = p_nd->m_p_left;
    node_pointer p_r = p_nd->m_p_right;
  
    base_type::update_min_max_for_erased_node(p_nd);
    base_type::actual_erase_node(p_nd);
    if (p_r == 0)
      {
        base_type::m_p_head->m_p_parent = p_l;
        if (p_l != 0)
  	p_l->m_p_parent = base_type::m_p_head;
        PB_DS_ASSERT_VALID((*this))
        return;
      }
  
    node_pointer p_target_r = leftmost(p_r);
    _GLIBCXX_DEBUG_ASSERT(p_target_r != 0);
    p_r->m_p_parent = base_type::m_p_head;
    base_type::m_p_head->m_p_parent = p_r;
    splay(p_target_r);
  
    _GLIBCXX_DEBUG_ONLY(p_target_r->m_p_left = 0);
    _GLIBCXX_DEBUG_ASSERT(p_target_r->m_p_parent == this->m_p_head);
    _GLIBCXX_DEBUG_ASSERT(this->m_p_head->m_p_parent == p_target_r);
  
    p_target_r->m_p_left = p_l;
    if (p_l != 0)
      p_l->m_p_parent = p_target_r;
    PB_DS_ASSERT_VALID((*this))
    this->apply_update(p_target_r, (node_update*)this);
  }
  
  PB_DS_CLASS_T_DEC
  inline typename PB_DS_CLASS_C_DEC::node_pointer
  PB_DS_CLASS_C_DEC::
  leftmost(node_pointer p_nd)
  {
    _GLIBCXX_DEBUG_ASSERT(p_nd != 0);
    while (p_nd->m_p_left != 0)
      p_nd = p_nd->m_p_left;
    return p_nd;
  }
  #endif
  