"I don't know much about this thing but I don't like it, and I know even less about this other thing and I like it even less!" For what it's worth, C++ has HKT

"I don't know much about this thing but I don't like it, and I know even less about this other thing and I like it even less!" For what it's worth, C++ has HKTs in the form of template template parameters, making it possible to write, e.g., monad transformers, which cannot be done in Rust, last I checked. Now as for whether you'd actually want to do this in a production codebase...