libstdc++
trie_policy/node_metadata_selector.hpp
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1 // -*- C++ -*-
2 
3 // Copyright (C) 2005-2014 Free Software Foundation, Inc.
4 //
5 // This file is part of the GNU ISO C++ Library. This library is free
6 // software; you can redistribute it and/or modify it under the terms
7 // of the GNU General Public License as published by the Free Software
8 // Foundation; either version 3, or (at your option) any later
9 // version.
10 
11 // This library is distributed in the hope that it will be useful, but
12 // WITHOUT ANY WARRANTY; without even the implied warranty of
13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 // General Public License for more details.
15 
16 // Under Section 7 of GPL version 3, you are granted additional
17 // permissions described in the GCC Runtime Library Exception, version
18 // 3.1, as published by the Free Software Foundation.
19 
20 // You should have received a copy of the GNU General Public License and
21 // a copy of the GCC Runtime Library Exception along with this program;
22 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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24 
25 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
26 
27 // Permission to use, copy, modify, sell, and distribute this software
28 // is hereby granted without fee, provided that the above copyright
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35 
36 /**
37  * @file trie_policy/node_metadata_selector.hpp
38  * Contains an implementation class for tries.
39  */
40 
41 #ifndef PB_DS_TRIE_NODE_METADATA_DISPATCH_HPP
42 #define PB_DS_TRIE_NODE_METADATA_DISPATCH_HPP
43 
46 
47 namespace __gnu_pbds
48 {
49  namespace detail
50  {
51  /**
52  * @addtogroup traits Traits
53  * @{
54  */
55 
56  /// Trie metadata helper.
57  template<typename Node_Update, bool _BTp>
59 
60  /// Specialization, false.
61  template<typename Node_Update>
62  struct trie_metadata_helper<Node_Update, false>
63  {
64  typedef typename Node_Update::metadata_type type;
65  };
66 
67  /// Specialization, true.
68  template<typename Node_Update>
69  struct trie_metadata_helper<Node_Update, true>
70  {
71  typedef null_type type;
72  };
73 
74  /// Trie node metadata dispatch.
75  template<typename Key,
76  typename Data,
77  typename Cmp_Fn,
78  template<typename Node_CItr,
79  typename Const_Iterator,
80  typename Cmp_Fn_,
81  typename _Alloc_>
82  class Node_Update,
83  typename _Alloc>
85  {
86  private:
88  typedef Node_Update<__it_type, __it_type, Cmp_Fn, _Alloc> __node_u;
90 
91  enum
92  {
93  null_update = is_same<__node_u, __nnode_u>::value
94  };
95 
96  public:
98  };
99  //@}
100  } // namespace detail
101 } // namespace __gnu_pbds
102 
103 #endif // #ifndef PB_DS_TRIE_NODE_METADATA_DISPATCH_HPP
Represents no type, or absence of type, for template tricks.
A null node updator, indicating that no node updates are required.