This is a good summary of the power of Julia's type system in performance. The `2^-5` seems like a bad example, tho, because it renders as a float. Every version of Julia I can run also allows it to work. I assume this used to error?

Yeah, the article is slightly out of date. There is no error in Julia 1.11 and 1.10. I no longer have earlier versions installed, so I don’t know when this changed.

This changed with v1.0 with the introduction of literal_pow and the interprocedural optimizations necessary so that compile-time constants (literal numbers) could optimize this case and determine the alternative type. Yeah this was written almost 10 years ago so it may need a little bit of love.