/in/foo.cc: In function 'int GetLevel(char)':
/in/foo.cc:58:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'double Operate(double, char, double)':
/in/foo.cc:74:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^