是否可以牺牲const-correctness的速度？

I have a factory class that will be used to create a whole lot of instances of a certain class. The creation process is pretty obfuscated and might require a quite a while. So I was thinking it would be smart to store the instances of the class which have already been created inside the factory, I can recall them at a later time.I have a factory class that will be used to cre