Method GetOrCreate

Bcore/src/main/cpp/base/safe_map.h:132–141

  template <typename CreateFn>
  V GetOrCreate(const K& k, CreateFn create) {
    static_assert(std::is_same<V, typename std::result_of<CreateFn()>::type>::value,
                  "Argument `create` should return a value of type V.");
    auto lb = lower_bound(k);
    if (lb != end() && !key_comp()(k, lb->first)) {
      return lb->second;
    }
    auto it = PutBefore(lb, k, create());
    return it->second;
  }

  iterator FindOrAdd(const K& k, const V& v) {
    iterator it = find(k);