Salastil/ncmpcpp
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

song list: get rid of boost::zip_iterator and improve {Const,}SongIterator

Browse Source
This commit is contained in:
Andrzej Rybczak
2016-12-08 04:28:43 +01:00
parent 612f8c3145
commit b7386c4fa6
15 changed files with 244 additions and 161 deletions
Download Patch File Download Diff File Expand all files Collapse all files

48
src/helpers/song_iterator_maker.h
View File

@@ -22,26 +22,48 @@
#define NCMPCPP_HELPERS_SONG_ITERATOR_MAKER_H
#include <boost/iterator/transform_iterator.hpp>
#include <boost/iterator/zip_iterator.hpp>
#include "menu.h"
#include "song_list.h"
template <typename ItemT, typename TransformT>
SongIterator makeSongIterator_(typename NC::Menu<ItemT>::Iterator it, TransformT &&map)
template <typename SongT>
struct SongPropertiesExtractor
{
return SongIterator(boost::make_zip_iterator(boost::make_tuple(
typename NC::Menu<ItemT>::PropertiesIterator(it),
boost::make_transform_iterator(it, std::forward<TransformT>(map))
)));
template <typename ItemT>
auto &operator()(ItemT &item) const
{
return m_cache.assign(&item.properties(), &item.value());
}
private:
mutable SongProperties m_cache;
};
template <typename IteratorT>
SongIterator makeSongIterator(IteratorT it)
{
typedef SongPropertiesExtractor<
typename IteratorT::value_type::Type
> Extractor;
static_assert(
std::is_convertible<
typename std::result_of<Extractor(typename IteratorT::reference)>::type,
SongProperties &
>::value, "invalid result type of SongPropertiesExtractor");
return SongIterator(boost::make_transform_iterator(it, Extractor{}));
}
template <typename ItemT, typename TransformT>
ConstSongIterator makeConstSongIterator_(typename NC::Menu<ItemT>::ConstIterator it, TransformT &&map)
template <typename ConstIteratorT>
ConstSongIterator makeConstSongIterator(ConstIteratorT it)
{
return ConstSongIterator(boost::make_zip_iterator(boost::make_tuple(
typename NC::Menu<ItemT>::ConstPropertiesIterator(it),
boost::make_transform_iterator(it, std::forward<TransformT>(map))
)));
typedef SongPropertiesExtractor<
typename ConstIteratorT::value_type::Type
> Extractor;
static_assert(
std::is_convertible<
typename std::result_of<Extractor(typename ConstIteratorT::reference)>::type,
const SongProperties &
>::value, "invalid result type of SongPropertiesExtractor");
return ConstSongIterator(boost::make_transform_iterator(it, Extractor{}));
}
#endif // NCMPCPP_HELPERS_SONG_ITERATOR_MAKER_H