+/**
+ * Wrapper to free(3), hides const compilation noise, permit NULL, return NULL.
+ * @param p memory to free
+ * @retval NULL always
+ */
+/*@unused@*/ static inline /*@null@*/ void *
+_free(/*@only@*/ /*@null@*/ const void * p)
+ /*@modifies p @*/
+{
+ if (p != NULL) free((void *)p);
+ return NULL;
+}
+