foo.cc: In function 'bool is_prime(int)':
foo.cc:19:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
foo.cc: In function 'bool is_palindrome(int)':
foo.cc:41:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^

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