DateTime#to_date

static VALUE
datetime_to_date(VALUE self)
{
    get_d1a(self);

    if (simple_dat_p(adat)) {
        VALUE new = d_lite_s_alloc_simple(cDate);
        {
            get_d1b(new);
            bdat->s = adat->s;
            bdat->s.jd = m_local_jd(adat);
            return new;
        }
    }
    else {
        VALUE new = d_lite_s_alloc_simple(cDate);
        {
            get_d1b(new);
            copy_complex_to_simple(new, &bdat->s, &adat->c);
            bdat->s.jd = m_local_jd(adat);
            bdat->s.flags &= ~(HAVE_DF | HAVE_TIME | COMPLEX_DAT);
            return new;
        }
    }
}