[NotableAlamode]

I understand that 1.0 was / is a priority. But I wonder what the state of discussions about HKTs in Rust is: is this addition believed to be an easy problem in the sense that it may be a lot of work, but no major roadblocks are expected? Or are there open questions that require substantial research?

[steveklabnik]

The state is, "this should be backwards compatible, therefore, we don't need to think about it more until after 1.0." That's pretty much it. There isn't an active discussion, because we're actively discussing the things needed to ship 1.0.