static private void errInfoSetter(object val, uint id, GlobalEntry gb, NetRuby rb)
{
RThread th = rb.GetCurrentContext();
if (val != null)
{
RBasic b = rb.InstanceOf(val);
if (b.IsKindOf(rb.eException) == false)
throw new eTypeError("assigning non-exception to $!");
}
th.errInfo = (RException)val;
}
