1 // -*- C++ -*-
2 
3 // Copyright (C) 2005, 2006 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 2, 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 // You should have received a copy of the GNU General Public License
17 // along with this library; see the file COPYING.  If not, write to
18 // the Free Software Foundation, 59 Temple Place - Suite 330, Boston,
19 // MA 02111-1307, USA.
20 
21 // As a special exception, you may use this file as part of a free
22 // software library without restriction.  Specifically, if other files
23 // instantiate templates or use macros or inline functions from this
24 // file, or you compile this file and link it with other files to
25 // produce an executable, this file does not by itself cause the
26 // resulting executable to be covered by the GNU General Public
27 // License.  This exception does not however invalidate any other
28 // reasons why the executable file might be covered by the GNU General
29 // Public License.
30 
31 // Copyright (C) 2004 Ami Tavory and Vladimir Dreizin, IBM-HRL.
32 
33 // Permission to use, copy, modify, sell, and distribute this software
34 // is hereby granted without fee, provided that the above copyright
35 // notice appears in all copies, and that both that copyright notice
36 // and this permission notice appear in supporting documentation. None
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38 // representation about the suitability of this software for any
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40 // warranty.
41 
42 /**
43  * @file node_metadata_selector.hpp
44  * Contains an implementation class for tries.
45  */
46 
47 #ifndef PB_DS_TRIE_NODE_METADATA_SELECTOR_HPP
48 #define PB_DS_TRIE_NODE_METADATA_SELECTOR_HPP
49 
50 #include <ext/pb_ds/detail/basic_tree_policy/null_node_metadata.hpp>
51 #include <ext/pb_ds/detail/types_traits.hpp>
52 
53 namespace pb_ds
54 {
55   namespace detail
56   {
57 
58     template<typename Node_Update, bool Null>
59     struct trie_metadata_helper
60     {
61       typedef typename Node_Update::metadata_type type;
62     };
63 
64     template<typename Node_Update>
65     struct trie_metadata_helper<
66       Node_Update,
67       true>
68     {
69       typedef null_node_metadata type;
70     };
71 
72     template<typename Key,
73 	     typename Data,
74 	     class Cmp_Fn,
75 	     template<typename Const_Node_Iterator,
76 		      class Const_Iterator,
77 		      class Cmp_Fn_,
78 		      class Allocator_>
79     class Node_Update,
80 	     class Allocator>
81     struct trie_node_metadata_selector
82     {
83     private:
84       typedef
85       dumconst_node_iterator<
86       Key,
87       Data,
88       Allocator>
89       dumconst_node_it;
90 
91       enum
92 	{
93 	  null_update =
94 	  is_same<
95 	  Node_Update<
96 	  dumconst_node_it,
97 	  dumconst_node_it,
98 	  Cmp_Fn,
99 	  Allocator>,
100 	  null_trie_node_update<
101 	  dumconst_node_it,
102 	  dumconst_node_it,
103 	  Cmp_Fn,
104 	  Allocator> >::value
105 	};
106 
107     public:
108       typedef
109       typename trie_metadata_helper<
110       Node_Update<
111       dumconst_node_it,
112       dumconst_node_it,
113       Cmp_Fn,
114       Allocator>,
115       null_update>::type
116       type;
117     };
118 
119   } // namespace detail
120 } // namespace pb_ds
121 
122 #endif // #ifndef PB_DS_TRIE_NODE_METADATA_SELECTOR_HPP
123