var u30 uint64 = 0;

var u31 uint64 = 1;

_, _ = u30, u31;

var u32 uint64 = 18446744073709551615;

var u33 uint64 = +18446744073709551615;

if u32 != (1<<64)-1 { panic("u32\n"); }

if u33 != (1<<64)-1 { panic("u33\n"); }

var i34 int64 = ^0; // note: 2's complement means ^0 == -1

if i34 != -1 { panic("i34") }