stats_ctor_vsd_numeric
iv = stats_ctor_vsd_numeric(0);
.lb = stats_ctor_vsd_numeric(lbd), \
.ub = stats_ctor_vsd_numeric(ubd), \
#define DRBKT(lb, ub) { stats_ctor_vsd_numeric(lb), stats_ctor_vsd_numeric(ub) }