I'm all for having generic associated types too, but by your own argument > Part of the reason is conservatism about language features, and wanting 'only one w

I'm all for having generic associated types too, but by your own argument > Part of the reason is conservatism about language features, and wanting 'only one way to do it But for the things HKTs are good for, it's much more usable: easy to teach, simpler errors. Dare I say HKT is the conservative choice. > But another part is that Rust is starved for compiler implementation manpower. That's a bummer, and I wish you the best in finding new sources of funding. But if HKT is easier, that's another reason to do it first. > There's also another, somewhat more mundane problem... I don't think either of us thinks that is insurmountable :)