/in/foo.cc: In function 'int main()':
/in/foo.cc:10:15: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   d=28+(y%4==0&&y%100||y%400=0);
         ~~~~~~^~~~~~~
/in/foo.cc:10:30: error: lvalue required as left operand of assignment
   d=28+(y%4==0&&y%100||y%400=0);
                              ^