3 ms·

const type field in the base class, non-virtual accessor (direct field access can be inlined). Memory vs CPU, the usual trade off.

• euyyn 9y ago
  It wouldn't cost memory though, because you free up a slot in the virtual table. No?
  • jonhohle 9y ago
    Virtual table should be one per class. A type field would be once per instance.
    • euyyn 9y ago
      Ah, right, static fields in C++ can't be overridden. If they could, they could be implemented by stuffing them in the virtual table and the cost in space would be O(classes) instead of O(instances).
  • deleted 9y ago
    [deleted]