/in/foo.cc: In function 'int main()':
/in/foo.cc:14:12: error: unable to find numeric literal operator 'operator""\U0000ff1b'
   14 |     return 0；
      |            ^~~
/in/foo.cc:14:12: note: use '-fext-numeric-literals' to enable more built-in suffixes
/in/foo.cc:14:15: error: expected ';' before '}' token
   14 |     return 0；
      |               ^
      |               ;
   15 | }
      | ~