ov_tree_map_/split_join_fn_imps.hpp

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// -*- C++ -*-

// Copyright (C) 2005-2018 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 ov_tree_map_/split_join_fn_imps.hpp
 * Contains an implementation class for ov_tree_.
 */

PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
split(key_const_reference r_key, PB_DS_CLASS_C_DEC& other)
{
  PB_DS_ASSERT_VALID((*this))
  PB_DS_ASSERT_VALID(other)

  if (m_size == 0)
    {
      other.clear();
      return;
    }

  if (Cmp_Fn::operator()(r_key, PB_DS_V2F(*begin())))
    {
      value_swap(other);
      PB_DS_ASSERT_VALID((*this))
      PB_DS_ASSERT_VALID(other)
      return;
    }

  if (!Cmp_Fn::operator()(r_key, PB_DS_V2F(*(end() - 1))))
    {
      return;
    }

  if (m_size == 1)
    {
      value_swap(other);
      PB_DS_ASSERT_VALID((*this))
      PB_DS_ASSERT_VALID(other)
      return;
    }

  iterator it = upper_bound(r_key);
  PB_DS_CLASS_C_DEC new_other(other, other);
  new_other.copy_from_ordered_range(it, end());
  PB_DS_CLASS_C_DEC new_this(*this, *this);
  new_this.copy_from_ordered_range(begin(), it);

  // No exceptions from this point.
  other.update(other.node_begin(), (node_update*)(&other));
  update(node_begin(), (node_update*)this);
  other.value_swap(new_other);
  value_swap(new_this);
  PB_DS_ASSERT_VALID((*this))
  PB_DS_ASSERT_VALID(other)
}

PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
join(PB_DS_CLASS_C_DEC& other)
{
  PB_DS_ASSERT_VALID((*this))
  PB_DS_ASSERT_VALID(other)
  if (other.m_size == 0)
    return;

  if (m_size == 0)
    {
      value_swap(other);
      PB_DS_ASSERT_VALID((*this))
      PB_DS_ASSERT_VALID(other)
      return;
    }

  const bool greater = Cmp_Fn::operator()(PB_DS_V2F(*(end() - 1)),
                                          PB_DS_V2F(*other.begin()));

  const bool lesser = Cmp_Fn::operator()(PB_DS_V2F(*(other.end() - 1)),
                                         PB_DS_V2F(*begin()));

  if (!greater && !lesser)
    __throw_join_error();

  PB_DS_CLASS_C_DEC new_this(*this, *this);

  if (greater)
    new_this.copy_from_ordered_range(begin(), end(),
                                     other.begin(), other.end());
  else
    new_this.copy_from_ordered_range(other.begin(), other.end(),
                                     begin(), end());

  // No exceptions from this point.
  value_swap(new_this);
  other.clear();
  PB_DS_ASSERT_VALID((*this))
  PB_DS_ASSERT_VALID(other)
}