-void (*signal(int sig, void (*func)(int)))(int); +typeof(void (int)) *signal(int sig, typeof(void (int)) *func); Much better honestly. The original took m

-void (*signal(int sig, void (*func)(int)))(int); +typeof(void (int)) *signal(int sig, typeof(void (int)) *func); Much better honestly. The original took me a few reads to understand, until I noticed the outer (int) is part of the return type.