static char *opt_hash= NULL;
/* Print the keys and counter how many were found */
-static memcached_return_t key_printer(memcached_st *ptr __attribute__((unused)),
+static memcached_return_t key_printer(const memcached_st *ptr __attribute__((unused)),
const char *key, size_t key_length,
void *context __attribute__((unused)))
{