foo.cc: In function ‘int main()’:
foo.cc:16:12: error: unable to find numeric literal operator ‘operator""；’
   16 |     return 0；
      |            ^~~
foo.cc:16:12: note: use ‘-fext-numeric-literals’ to enable more built-in suffixes
foo.cc:16:15: error: expected ‘;’ before ‘}’ token
   16 |     return 0；
      |               ^
      |               ;
   17 | }
      | ~