Exheredludis/paludis/metadata_key_holder.hh
2012-04-15 14:51:19 +01:00

83 lines
2.9 KiB
C++

/* vim: set sw=4 sts=4 et foldmethod=syntax : */
/*
* Copyright (c) 2008, 2009, 2010, 2011 Ciaran McCreesh
*
* This file is part of the Paludis package manager. Paludis is free software;
* you can redistribute it and/or modify it under the terms of the GNU General
* Public License version 2, as published by the Free Software Foundation.
*
* Paludis 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.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef PALUDIS_GUARD_PALUDIS_METADATA_KEY_HOLDER_HH
#define PALUDIS_GUARD_PALUDIS_METADATA_KEY_HOLDER_HH 1
#include <paludis/metadata_key_holder-fwd.hh>
#include <paludis/util/pimp.hh>
#include <paludis/util/wrapped_forward_iterator.hh>
#include <paludis/metadata_key-fwd.hh>
#include <memory>
namespace paludis
{
/**
* Generic interface for any class that holds a number of MetadataKey
* instances.
*
* \since 0.26
* \ingroup g_metadata_key
*/
class PALUDIS_VISIBLE MetadataKeyHolder
{
private:
Pimp<MetadataKeyHolder> _imp;
protected:
/**
* Add a new MetadataKey, which must not use the same raw name as
* any previous MetadataKey added to this ID.
*/
virtual void add_metadata_key(const std::shared_ptr<const MetadataKey> &) const;
/**
* Clear all MetadataKey instances added using add_metadata_key.
*/
virtual void clear_metadata_keys() const;
/**
* This method will be called before any of the metadata key
* iteration methods does its work. It can be used by subclasses to
* implement as-needed loading of keys.
*/
virtual void need_keys_added() const = 0;
public:
MetadataKeyHolder();
virtual ~MetadataKeyHolder() = 0;
///\name Finding and iterating over metadata keys
///\{
struct MetadataConstIteratorTag;
typedef WrappedForwardIterator<MetadataConstIteratorTag, const std::shared_ptr<const MetadataKey> > MetadataConstIterator;
MetadataConstIterator begin_metadata() const PALUDIS_ATTRIBUTE((warn_unused_result));
MetadataConstIterator end_metadata() const PALUDIS_ATTRIBUTE((warn_unused_result));
MetadataConstIterator find_metadata(const std::string &) const PALUDIS_ATTRIBUTE((warn_unused_result));
///\}
};
extern template class PALUDIS_VISIBLE WrappedForwardIterator<MetadataKeyHolder::MetadataConstIteratorTag, const std::shared_ptr<const MetadataKey> >;
}
#endif