The boxing there is perfectly idiomatic. Your code is likely to result in a pile of unnecessary code bloat, due to monomorphising the generic function twice, ra

The boxing there is perfectly idiomatic. Your code is likely to result in a pile of unnecessary code bloat, due to monomorphising the generic function twice, rather than just using dynamic dispatch (the overhead of which is likely trivial for IO operations). I would say that the dense layout is more confusing/weird than the actual operations the code is doing.