/in/foo.cc: In function 'bool f(int)':
/in/foo.cc:9:41: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
  if (year % 400 == 0 || year % 100 != 0 && year % 4 == 0) return true;
                         ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~
/in/foo.cc: In function 'bool operator<(person&, person&)':
/in/foo.cc:126:2: warning: control reaches end of non-void function [-Wreturn-type]
  }
  ^