-bool hash_rehash (Hash_table *, size_t);
-void *hash_insert (Hash_table *, const void *);
+bool hash_rehash (Hash_table *, size_t) _GL_ATTRIBUTE_WUR;
+void *hash_insert (Hash_table *, const void *) _GL_ATTRIBUTE_WUR;
+int hash_insert0 (Hash_table *table, const void *entry,
+ const void **matched_ent);