* functions are wrapped in cmp_a_## and cmp_d_## functions that do
* void * to const playlist_item_t * casting and dereferencing and
* cmp_d_## inverts the result, too. proto_## are static inline,
* functions are wrapped in cmp_a_## and cmp_d_## functions that do
* void * to const playlist_item_t * casting and dereferencing and
* cmp_d_## inverts the result, too. proto_## are static inline,