Comment by Parodper

> That's famously a single-pass compiler. Rust is famously unable to compile in a single pass.

I probably should have replied under the other comment. I was also referring to your

> No, I didn't - I asked how sum types were supposed to work in an era of 64KB memory systems.

But context got lost between replies.

> that's why C is what it is

C famously had a big redesign in 1990. The language of today isn't the same K&R printed.