Fastest container or algorithm for unique reusable ids in C++

Question

I have a need for unique reusable ids. The user can choose his own ids or he can ask for a free one. The API is basically

class IdManager {
public:
  int Allocat         


        

Answer 1

Normally, i'd say stick to an simple implementation until you have an idea of which methods are used most. Premature tuning might prove wrong. Use the simple implementation, and log its use, then you can optimize from the functions that are used the most. No use in optimizing for quick removal or quick allocation if you only need a couple of hundred ids and a simple vector would be enough.