zero?

/*
 *  call-seq:
 *     num.zero?    => true or false
 *
 *  Returns <code>true</code> if <i>num</i> has a zero value.
 */

static VALUE
num_zero_p(num)
    VALUE num;
{
    if (rb_equal(num, INT2FIX(0))) {
        return Qtrue;
    }
    return Qfalse;
}