/* * Copyright 2003-2018 The Music Player Daemon Project * http://www.musicpd.org * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2 of the License, or * (at your option) any later version. * * This program 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., * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. */ #ifndef MPD_TAG_FALLBACK_HXX #define MPD_TAG_FALLBACK_HXX #include template bool ApplyTagFallback(TagType type, F &&f) noexcept { if (type == TAG_ALBUM_ARTIST_SORT) { /* fall back to "AlbumArtist", "ArtistSort" and "Artist" if no "AlbumArtistSort" was found */ if (f(TAG_ALBUM_ARTIST)) return true; return ApplyTagFallback(TAG_ARTIST_SORT, std::forward(f)); } if (type == TAG_ALBUM_ARTIST || type == TAG_ARTIST_SORT) /* fall back to "Artist" if no "AlbumArtist"/"ArtistSort" was found */ return f(TAG_ARTIST); return false; } template bool ApplyTagWithFallback(TagType type, F &&f) noexcept { return f(type) || ApplyTagFallback(type, std::forward(f)); } #endif