struct psi_plist *psi_plist_ins(struct psi_plist *list, size_t index, void *ptr);
struct psi_plist *psi_plist_ins_r(struct psi_plist *list, size_t offset_start, size_t num_eles, void **eles);
+bool psi_plist_unset(struct psi_plist *list, size_t index);
+
bool psi_plist_shift(struct psi_plist *list, void *ptr);
bool psi_plist_pop(struct psi_plist *list, void *ptr);
bool psi_plist_top(struct psi_plist *list, void *ptr);