Static initialized map

enum class Type : int {
    Song,
    Artist,
    Release,
    Playlist
};

static const std::map< Type, std::string > TypeStrings{
    { Type::Song,       "song"      },
    { Type::Artist,     "artist"    },
    { Type::Release,    "release"   },
    { Type::Playlist,   "playlist"  }
};