- route_cache_element_t elm = nullptr;
- if (not routeCache_.empty()) { /* cache mode */
- auto it = routeCache_.find(src_id);
- elm = (it == routeCache_.end()) ? nullptr : it->second;
- }
-
- if (elm) { /* cached mode and cache hit */
- pred_arr = elm->pred_arr;
- } else { /* not cached mode, or cache miss */
+ auto elm = routeCache_.emplace(src_id, std::vector<int>());
+ std::vector<int>& pred_arr = elm.first->second;