1 extern int printf(const char *, ...); 2 3 /* Brought up by Harald van Dijk */ 4 int main()5 main() { 6 int (*f)(const char *msg); 7 8 puts("hello"); 9 printf("%d\n", (int)sizeof &puts); 10 (f = puts)("world"); 11 return 0; 12 } 13 14 15