pc_idx
pc->pc_idx = idx;
? prop_array_get(o, pc->pc_idx)
return prop_array_set(po, pc->pc_idx, v) ? 0 : ENOMEM;
return prop_array_set(po, pc->pc_idx, v) ? 0 : ENOMEM;
prop_array_remove(po, pc->pc_idx);
? (prop_array_remove(npo, pc->pc_idx), true)
: prop_array_set(npo, pc->pc_idx, v);
return pc->pc_idx;