It's a perfectly reasonable niche use case for achieving maximum performance. My main issues with it are: 1. Like many other performance optimizations, it is

It's a perfectly reasonable niche use case for achieving maximum performance. My main issues with it are: 1. Like many other performance optimizations, it is a trade-off. You may be sacrificing easy maintenance or even introducing breakage (if the person using it doesn't understand the limitations and implications). So IMHO you should only do it if you can show through profiling, etc. that the gain is real and worth it. 2. As a matter of language ergonomics, it should never be something that anyone does unknowingly. You should have to explicitly ask for it. The type name should be something blindingly obviously like "native_int" or "word_int".