(  style == default_rounding_style() && style != r_indeterminate
(  a_style == default_rounding_style() && a_style != r_indeterminate
round_to<RealType>::select_rounding_function(rounding_style style) const{    if        (  style == default_rounding_style()        && style != r_indeterminate        )        {        return detail::perform_rint;        }    switch(style)        {        case r_toward_zero:            {            return detail::round_trunc;            }        case r_to_nearest:            {            return detail::round_near;            }        case r_upward:            {            return detail::round_up;            }        case r_downward:            {            return detail::round_down;            }        case r_current:            {            return detail::perform_rint;            }        case r_not_at_all:            {            return detail::round_not;            }        default:            {            throw std::domain_error("Invalid rounding style.");            }        }}