/in/foo.cc: In function 'bool is_prime(int)':
/in/foo.cc:22:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'bool is_palindrome(int)':
/in/foo.cc:47:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^