Don't see any problem there, how does it relate to portability? Anyway games are going to pre-allocate large arrays and work on them, for cache affinity. That

Don't see any problem there, how does it relate to portability? Anyway games are going to pre-allocate large arrays and work on them, for cache affinity. That doesn't depend on C++ vs. Java. No need to create a separate object for each item in your factory, but rather a row in the array(s). And even if you do create a new object for each item, it's better to do that on heavily optimized heap, than manually allocating/deallocating memory in the same thread. You end up writing that heap in C++ anyway.