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
37// of the above authors, nor IBM Haifa Research Laboratories, make any
38// representation about the suitability of this software for any
39// purpose. It is provided "as is" without express or implied
40// warranty.
41
42/**
43 * @file sample_update_policy.hpp
44 * Contains a sample policy for list update containers.
45 */
46
47#ifndef PB_DS_SAMPLE_UPDATE_POLICY_HPP
48#define PB_DS_SAMPLE_UPDATE_POLICY_HPP
49
50// A sample list-update policy.
51struct sample_update_policy
52{
53  // Default constructor.
54  sample_update_policy();
55
56  // Copy constructor.
57  sample_update_policy(const sample_update_policy&);
58
59  // Swaps content.
60  inline void
61  swap(sample_update_policy& other);
62
63protected:
64  // Metadata on which this functor operates.
65  typedef some_metadata_type metadata_type;
66
67  // Creates a metadata object.
68  metadata_type
69  operator()() const;
70
71  // Decides whether a metadata object should be moved to the front of
72  // the list. A list-update based containers object will call this
73  // method to decide whether to move a node to the front of the
74  // list. The method shoule return true if the node should be moved
75  // to the front of the list.
76  bool
77  operator()(metadata_reference) const;
78};
79
80#endif
81