standard_policies.hpp

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// -*- C++ -*-

// Copyright (C) 2005, 2006, 2007, 2009 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 standard_policies.hpp
 * Contains standard policies for containers.
 */

#ifndef PB_DS_STANDARD_POLICIES_HPP
#define PB_DS_STANDARD_POLICIES_HPP

#include <memory>
#include <ext/pb_ds/hash_policy.hpp>
#include <ext/pb_ds/list_update_policy.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/detail/basic_tree_policy/null_node_metadata.hpp>
#include <ext/pb_ds/trie_policy.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
#include <tr1/functional>

namespace __gnu_pbds
{
  namespace detail
  {
    template<typename Key>
    struct default_hash_fn
    {
      typedef std::tr1::hash<Key> type;
    };

    template<typename Key>
    struct default_eq_fn
    {
      typedef std::equal_to<Key> type;
    };

    enum
      {
    default_store_hash = false
      };

    struct default_comb_hash_fn
    {
      typedef __gnu_pbds::direct_mask_range_hashing<> type;
    };

    template<typename Comb_Hash_Fn>
    struct default_resize_policy
    {
    private:
      typedef typename Comb_Hash_Fn::size_type size_type;

      typedef __gnu_pbds::direct_mask_range_hashing<size_type> default_fn;
      typedef is_same<default_fn, Comb_Hash_Fn> same_type;
      typedef __gnu_pbds::hash_exponential_size_policy<size_type> iftrue;
      typedef __gnu_pbds::hash_prime_size_policy iffalse;
      typedef __conditional_type<same_type::value, iftrue, iffalse> cond_type;
      typedef typename cond_type::__type size_policy_type;

      typedef __gnu_pbds::hash_load_check_resize_trigger<false, size_type> trigger;

    public:
      typedef __gnu_pbds::hash_standard_resize_policy<size_policy_type, trigger, false, size_type> type;
    };

    struct default_update_policy
    {
      typedef __gnu_pbds::move_to_front_lu_policy<> type;
    };

    template<typename Comb_Probe_Fn>
    struct default_probe_fn
    {
    private:
      typedef typename Comb_Probe_Fn::size_type size_type;

      typedef __gnu_pbds::direct_mask_range_hashing<size_type> default_fn;
      typedef is_same<default_fn, Comb_Probe_Fn> same_type;
      typedef __gnu_pbds::linear_probe_fn<size_type> iftrue;
      typedef __gnu_pbds::quadratic_probe_fn<size_type> iffalse;
      typedef __conditional_type<same_type::value, iftrue, iffalse> cond_type;

    public:
      typedef typename cond_type::__type type;
    };

    template<typename Key>
    struct default_trie_e_access_traits;

    template<typename Char, class Char_Traits>
    struct default_trie_e_access_traits<std::basic_string<Char, Char_Traits, std::allocator<char> > >
    {
    private:
      typedef std::basic_string<Char, Char_Traits, std::allocator<char> > string_type;

    public:
      typedef __gnu_pbds::string_trie_e_access_traits<string_type> type;
    };

  } // namespace detail
} // namespace __gnu_pbds

#endif // #ifndef PB_DS_STANDARD_POLICIES_HPP