Any language’s implementation can do that in places as an optimization. But Haskell is one example where it doesn’t generally do that, and the code above works

Any language’s implementation can do that in places as an optimization. But Haskell is one example where it doesn’t generally do that, and the code above works. I never checked this question out for other languages, but Java, likewise, only supports generics on reference types and generates one bytecode per definition, so it should be similar to Haskell in that respect.