That's basically what I'm suggesting. Use it only on hot paths you've profiled, maintain purity elsewhere. Java pretty much requires you to make concessions i

That's basically what I'm suggesting. Use it only on hot paths you've profiled, maintain purity elsewhere. Java pretty much requires you to make concessions if you're trying to get maximum performance. Similarly: it has a garbage collector, but there are plenty of places where an object pool will out-perform it. Deliberately breaking / re-implementing part of the language for performance reasons.