Yes, that’s what I’m suggesting. Injecting some kind of metadata that gets stripped at code gen time would probably work.
worse incremental compilation performance
Would it really be that significant?
without allocating everything on the heap
I’m talking about compile time.
Start with all of the known safe cases (basic types should be fine), then move on to more dubious options (anything that supports iteration). Then allow iterable types but don’t allow iterating over a mutable reference. And so on. If it’s a priority to loosen up the rules without sacrificing safety, surely some solutions could be found to improve ergonomics.
Or perhaps there could be some annotations to make a reference as “unsafe” or similar instead of just a block. If something is safe in practice but not verifiably safe, there should be a way to communicate that.
You want some annotations to break out of the safe subset of the language
The annotations would indicate that something unsafe is going on, so it’s like an unsafe block, but on a reference. That way it’s clear that it’s not being checked by the borrow checker, but the rest of the application can be checked.
I really liked the idea of an optional, built-in GC w/ pre-1.0 Rust where specific references could be GC’d. If that were a thing in modern Rust (and the GC would only be enabled if there’s a GC’d reference included), we could get a lot more ergonomics around things like linked lists.
Yes, that’s what I’m suggesting. Injecting some kind of metadata that gets stripped at code gen time would probably work.
Would it really be that significant?
I’m talking about compile time.
Start with all of the known safe cases (basic types should be fine), then move on to more dubious options (anything that supports iteration). Then allow iterable types but don’t allow iterating over a mutable reference. And so on. If it’s a priority to loosen up the rules without sacrificing safety, surely some solutions could be found to improve ergonomics.
Or perhaps there could be some annotations to make a reference as “unsafe” or similar instead of just a block. If something is safe in practice but not verifiably safe, there should be a way to communicate that.
The annotations would indicate that something unsafe is going on, so it’s like an unsafe block, but on a reference. That way it’s clear that it’s not being checked by the borrow checker, but the rest of the application can be checked.
I really liked the idea of an optional, built-in GC w/ pre-1.0 Rust where specific references could be GC’d. If that were a thing in modern Rust (and the GC would only be enabled if there’s a GC’d reference included), we could get a lot more ergonomics around things like linked lists.