   hash/index type thing in C++
  If I have a system where a user can call AddBlah() and get an int back as an index of the Blah created... what is the best method of creating this index? Some Kind of hash (i.e. blahMap->count. If that is taken next, next, etc)?Internally I have a 'map' mapping an int to a structure for that blah.   
  It depends on what characteristics you want for your index. In general, a serial count variable is sufficient.   