/in/foo.cc:57:6: warning: multi-character character constant [-Wmultichar]
  case'（':return 4;
      ^~~~~
/in/foo.cc:58:6: warning: multi-character character constant [-Wmultichar]
  case'）':return 5;
      ^~~~~
/in/foo.cc: In function 'int ch_to_i(char)':
/in/foo.cc:57:2: warning: case label value exceeds maximum value for type
  case'（':return 4;
  ^~~~
/in/foo.cc:58:2: warning: case label value exceeds maximum value for type
  case'）':return 5;
  ^~~~
/in/foo.cc:61:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int Operate(int, char, int)':
/in/foo.cc:77:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^