There are many ways that are non breaking to implement this. I chose a particular one for example's sake. In reality, extracting an interface is a more valuable

There are many ways that are non breaking to implement this. I chose a particular one for example's sake. In reality, extracting an interface is a more valuable refactoring, and a likely valid one given that the optimization tradeoff is happening. So MemoryOptimizedFoo : IFoo, SpeedOptimizedFoo : IFoo...