void
ft(integer a, text &s)
{
    if (a & 1) {
	s = "odd";
	error("bad number");
    } elif (a & a - 1) {
	s = "not a power of two";
	error("bad number");
    }
}

void
fc(integer a)
{
    text e;

    if (trap(ft, a, e)) {
	v_text("exception of type `");
	v_text(e);
	v_text("' thrown for ");
	v_integer(a);
	v_newline();
    } else {
	v_text("no exception thrown for ");
	v_integer(a);
	v_newline();
    }
}

integer
main(void)
{
    fc(5);
    fc(6);
    fc(8);

    return 0;
}