hash_exponential_size_policy_imp.hpp

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// -*- C++ -*-

// Copyright (C) 2005-2017 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
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/**
 * @file hash_exponential_size_policy_imp.hpp
 * Contains a resize size policy implementation.
 */

PB_DS_CLASS_T_DEC
PB_DS_CLASS_C_DEC::
hash_exponential_size_policy(size_type start_size, size_type grow_factor) :
  m_start_size(start_size),
  m_grow_factor(grow_factor)
{ }

PB_DS_CLASS_T_DEC
void
PB_DS_CLASS_C_DEC::
swap(PB_DS_CLASS_C_DEC& other)
{
  std::swap(m_start_size, other.m_start_size);
  std::swap(m_grow_factor, other.m_grow_factor);
}

PB_DS_CLASS_T_DEC
typename PB_DS_CLASS_C_DEC::size_type
PB_DS_CLASS_C_DEC::
get_nearest_larger_size(size_type size) const
{
  size_type ret = m_start_size;
  while (ret <= size)
    {
      const size_type next_ret = ret*  m_grow_factor;
      if (next_ret < ret)
        __throw_insert_error();
      ret = next_ret;
    }
  return ret;
}

PB_DS_CLASS_T_DEC
typename PB_DS_CLASS_C_DEC::size_type
PB_DS_CLASS_C_DEC::
get_nearest_smaller_size(size_type size) const
{
  size_type ret = m_start_size;
  while (true)
    {
      const size_type next_ret = ret*  m_grow_factor;
      if (next_ret < ret)
        __throw_resize_error();
      if (next_ret >= size)
        return (ret);
      ret = next_ret;
    }
  return ret;
}