function f (v, i) {
    var c = v[i];
    switch (c) {
    case 0:
        assertEq(v[i], 0);
        break;
    case 1:
        assertEq(v[i], 1);
        break;
    default:
        assertEq(c === 0 || c === 1, false);
    }
}

var v = [
  0, 0.0, 0.1, 1, 1.0, 1.1,
  null, undefined, true, false, {}, "", "0", "1",
  { valueOf: function () { return 0; } },
  { valueOf: function () { return 1; } }
];
for (var i = 0; i < 100; i++)
    f(v, i % v.length);