Very, very few people have to think about unwind safety, because it really only comes into play when you're writing unsafe code, and relying on the ability for panics to be caught. Many folks aren't writing any unsafe, and many who are are doing it explicitly in a panic=abort environment. And most don't rely on panics being able to be caught in the first place.

So, some subset of library authors have to pay attention to unwind safety in some cases. This is hardly "everyone."

> pays the syntactic

It's one character.

> and runtime costs of error code checking,

Exceptions also have runtime costs. I'm not aware of anything demonstrating that there is a really major difference between the two in real systems. I would be interested in reading more about this! Most of the discussion I've seen focuses on microbenchmarks, which can be very different than real code.

> pays the runtime cost of unwind tables,

Only if you want them, as you yourself mention, you can turn this off. And many do.

No it isn't. With exceptions:

  fn foo() -> i32 {
    let x = bar();
    x + 1
  }

  fn foo() -> Result<i32, SomeErrorType> {
    let x = bar()?;
    Ok(x + 1)
  }

I do think it's not quite what you're saying though, due to Rust's design, we would have checked exceptions, and so the Result part would be there with exceptions, it's the Ok() part that would change.

In theory you could make a language without checked exceptions that would make it be like your example.

The practical, day-to-day implications of this still round to zero, though.

Vendors have been using similar language to downplay potential bugs for decades, usually to disastrous results. At one point, even memory safety wasn't a big deal. I'm just waiting for a software package to have a security vulnerability when an attacker is able to trigger an untested Rust unwind path and put some Rust daemon into a state it didn't expect.

There are many good parts of Rust, but I don't think I'm ever going to convinced that the error handling wasn't a huge and unfixable mistake. It's because error handling is such a big mistake that Rust has grown layers of syntactic sugar --- try!, !, etc. --- to paper over the ugly spot in the language.

> I don't think I'm ever going to convinced that the error handling wasn't a huge and unfixable mistake.

That's fine. No language can satisfy everyone.

1. It is not clear that we will ever be free of logic bugs to the same degree that we can minimize memory safety bugs.

2. We're in a specific context in this sub-thread, and that's that you claimed that this is a pervasive issue that everyone must consider all the time. These logic bugs can only be introduced in a context that is very unusual, and so my claim is not that logic bugs in general are irrelevant, but that the context that this kind of bug can appear is smaller than you say it is.

> logic bugs (where Rust is weak)

Rust gives you way more tools than C to reduce logic bugs as well.

The Rust way of dealing with errors is to return a Result<> and in my experience it's the best system I've used. It doesn't have the code flow breaking aspect of exceptions while being a lot nicer and less error-prone than C or Go style error handling.

Most libraries do not depend on a particular semantic, in my experience.

I happen to like exceptions in principle, but for a lot of low-level embedded code they're a deal breaker.