standard_policies.hpp

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// -*- 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 detail/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/detail/branch_policy/null_node_metadata.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/trie_policy.hpp>
#include <ext/pb_ds/tag_and_trait.hpp>
#include <tr1/functional>
 
namespace __gnu_pbds
{
  namespace detail
  {
    /// Primary template, default_hash_fn.
    template<typename Key>
    struct default_hash_fn
    {
        /// Dispatched type.
      typedef std::tr1::hash<Key>                               type;
    };
 
    /// Primary template, default_eq_fn.
    template<typename Key>
    struct default_eq_fn
    {
        /// Dispatched type.
      typedef std::equal_to<Key>                                type;
    };
 
    /// Enumeration for default behavior of stored hash data.
    enum
      {
        default_store_hash = false
      };
 
    /// Primary template, default_comb_hash_fn.
    struct default_comb_hash_fn
    {
        /// Dispatched type.
      typedef direct_mask_range_hashing<>                       type;
    };
 
    /// Primary template, default_resize_policy.
    template<typename Comb_Hash_Fn>
    struct default_resize_policy
    {
    private:
      typedef typename Comb_Hash_Fn::size_type                  size_type;
 
      typedef direct_mask_range_hashing<size_type>              default_fn;
      typedef is_same<default_fn, Comb_Hash_Fn>                 same_type;
      typedef hash_exponential_size_policy<size_type>           iftrue;
      typedef hash_prime_size_policy                            iffalse;
      typedef __conditional_type<same_type::value, iftrue, iffalse> cond_type;
      typedef typename cond_type::__type                       size_policy_type;
 
      typedef hash_load_check_resize_trigger<false, size_type>  trigger;
 
    public:
        /// Dispatched type.
      typedef hash_standard_resize_policy<size_policy_type, trigger, 
                                          false, size_type>     type;
    };
 
    /// Default update policy.
    struct default_update_policy
    {
        /// Dispatched type.
      typedef lu_move_to_front_policy<>                         type;
    };
 
    /// Primary template, default_probe_fn.
    template<typename Comb_Probe_Fn>
    struct default_probe_fn
    {
    private:
      typedef typename Comb_Probe_Fn::size_type                 size_type;
      typedef direct_mask_range_hashing<size_type>              default_fn;
      typedef is_same<default_fn, Comb_Probe_Fn>                same_type;
      typedef linear_probe_fn<size_type>                        iftrue;
      typedef quadratic_probe_fn<size_type>                     iffalse;
      typedef __conditional_type<same_type::value, iftrue, iffalse> cond_type;
 
    public:
        /// Dispatched type.
      typedef typename cond_type::__type                        type;
    };
 
 
    /// Primary template, default_trie_access_traits.
    template<typename Key>
      struct default_trie_access_traits;
 
#define __dtrie_alloc std::allocator<char>  
#define __dtrie_string std::basic_string<Char, Char_Traits, __dtrie_alloc> 
 
    /// Partial specialization, default_trie_access_traits.
    template<typename Char, typename Char_Traits>
      struct default_trie_access_traits<__dtrie_string>
      {
      private:
        typedef __dtrie_string                                  string_type;
 
      public:
        /// Dispatched type.
        typedef trie_string_access_traits<string_type>          type;
      };
 
#undef __dtrie_alloc
#undef __dtrie_string
 
  } // namespace detail
} // namespace __gnu_pbds
 
#endif // #ifndef PB_DS_STANDARD_POLICIES_HPP