foo.cc: In function ‘int year(int)’:
foo.cc:5:26: error: unable to find numeric literal operator ‘operator""）’
    5 | return （(y%4==0&&y%100!=0）||y%400==0)?1:0;
      |                          ^~~
foo.cc:5:26: note: use ‘-fext-numeric-literals’ to enable more built-in suffixes
foo.cc:5:8: error: ‘（’ was not declared in this scope
    5 | return （(y%4==0&&y%100!=0）||y%400==0)?1:0;
      |        ^~