> that's OCaml, a language with no value types (other than 31-bit ints) or RAII Hence the "managed language". Such features would certainly be more difficult

> that's OCaml, a language with no value types (other than 31-bit ints) or RAII Hence the "managed language". Such features would certainly be more difficult to do in Rust, and agreed that exceptions probably aren't the ideal error-handling mechanism given the goals of Rust. I guess the point was that exception tradeoffs can be mostly overcome by a well-designed implementation, given the appropriate language. (Not saying other languages have bad implementations, although the entire OCaml runtime is a work of art that's very nice in more ways than just exceptions...) > checked exceptions still require you to annotate signatures or catch the exception Could the signatures be inferred with the exception type(s)? Not catching them at some point in the call stack would result in a compile error; no reason it has to be at the caller. Probably tricky for libraries, maybe having a notion of scope for exceptions would be useful. Although I'll admit I don't know the first thing about the nuances of type inference. > the automatic wrapping and unwrapping of values in exception types I could be missing something, but how would this be worse than one or maybe two dereferences at catch-site(s) and nothing in between? Is the problem with exceptions containing large unboxed values that have to be propagated up the call stack? Since call stacks can be arbitrarily long, this seems like another good reason to limit the "scope" for exceptions somehow. > easiest thing to do to handle them is to write "try { ... } catch (Exception e) {}" True, generic pattern matching has the same problem with the 'default' case (eg, match _ -> ... ), that's often a code smell. Moreover, the notion of a syntactic try-block seems like something that a "sufficiently smart" compiler could do away with, given enough inference: just match on the "returned" exceptional values [1]. But then again, what do I know about type inference... [1] OCaml has a pretty nice feature which approximates this: https://blogs.janestreet.com/pattern-matching-and-exception-handling-unite/ https://blogs.janestreet.com/pattern-matching-and-exception-...