paludis  Version 2.6.0
metadata_key_holder.hh
1 /* vim: set sw=4 sts=4 et foldmethod=syntax : */
2 
3 /*
4  * Copyright (c) 2008, 2009, 2010, 2011 Ciaran McCreesh
5  *
6  * This file is part of the Paludis package manager. Paludis is free software;
7  * you can redistribute it and/or modify it under the terms of the GNU General
8  * Public License version 2, as published by the Free Software Foundation.
9  *
10  * Paludis is distributed in the hope that it will be useful, but WITHOUT ANY
11  * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
12  * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
13  * details.
14  *
15  * You should have received a copy of the GNU General Public License along with
16  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
17  * Place, Suite 330, Boston, MA 02111-1307 USA
18  */
19 
20 #ifndef PALUDIS_GUARD_PALUDIS_METADATA_KEY_HOLDER_HH
21 #define PALUDIS_GUARD_PALUDIS_METADATA_KEY_HOLDER_HH 1
22 
23 #include <paludis/metadata_key_holder-fwd.hh>
24 #include <paludis/util/pimp.hh>
25 #include <paludis/util/wrapped_forward_iterator.hh>
27 #include <memory>
28 
29 namespace paludis
30 {
31  /**
32  * Generic interface for any class that holds a number of MetadataKey
33  * instances.
34  *
35  * \since 0.26
36  * \ingroup g_metadata_key
37  */
39  {
40  private:
42 
43  protected:
44  /**
45  * Add a new MetadataKey, which must not use the same raw name as
46  * any previous MetadataKey added to this ID.
47  */
48  virtual void add_metadata_key(const std::shared_ptr<const MetadataKey> &) const;
49 
50  /**
51  * Clear all MetadataKey instances added using add_metadata_key.
52  */
53  virtual void clear_metadata_keys() const;
54 
55  /**
56  * This method will be called before any of the metadata key
57  * iteration methods does its work. It can be used by subclasses to
58  * implement as-needed loading of keys.
59  */
60  virtual void need_keys_added() const = 0;
61 
62  public:
64  virtual ~MetadataKeyHolder() = 0;
65 
66  ///\name Finding and iterating over metadata keys
67  ///\{
68 
69  struct MetadataConstIteratorTag;
71 
72  MetadataConstIterator begin_metadata() const PALUDIS_ATTRIBUTE((warn_unused_result));
73  MetadataConstIterator end_metadata() const PALUDIS_ATTRIBUTE((warn_unused_result));
74  MetadataConstIterator find_metadata(const std::string &) const PALUDIS_ATTRIBUTE((warn_unused_result));
75 
76  ///\}
77  };
78 
80 }
81 
82 #endif
Definition: pimp.hh:51
Definition: about_metadata-fwd.hh:23
Definition: wrapped_forward_iterator-fwd.hh:26
Definition: metadata_key_holder.hh:38
#define PALUDIS_ATTRIBUTE(x)
Definition: attributes.hh:53
#define PALUDIS_VISIBLE
Definition: attributes.hh:59