michael@0: function testObjectToNumber() {
michael@0:     var o = {valueOf: function()-3};
michael@0:     var x = 0;
michael@0:     for (var i = 0; i < 10; i++)
michael@0:         x -= o;
michael@0:     return x;
michael@0: }
michael@0: assertEq(testObjectToNumber(), 30);