Hhhmmm, interesting, thanks for reply!

That would be fairly interesting to look at the actual code you've used, and have a look at the codegen. By a chance, is it viable for you to open-source it? I'd guess it should bear lots of interest for Hana author/s.

What compiler/version did you use? For example, MSVC isn't (at least wasn't) good at always evaluating `constexpr` in compile-time...

> hana::while creates lambda functions, so perhaps a simple function optimization becomes a cross-unit affair if it calls hana::while. (speculating)

Hmm, I'd say it (LTO) shouldn't influence, as these lambdas are already fully visible to a compiler.