FFI unwind safety

[Mart-Bogdan]

Hello, really nice article, but there is one important point!

According to Nomicon https://doc.rust-lang.org/nomicon/ffi.html#ffi-and-panics

A panic! across an FFI boundary is undefined behavior.

I don't say that article should dig so deep, but please add Note/warning that in real use all functions that are called from FFI should use catch_unwind and report errors to native code in other way.

Taking into account that it could be used with any user-provided impls of Write, that is fairly possible to encounter panics.

P.S. Rust's catch unwind is fairly cheap and creates small overhead in case no panic actually happen,

[Mart-Bogdan]

It seems the wrong place to post this issue. Reposted to Michael-F-Bryan/adventures.michaelfbryan.com#36

[Michael-F-Bryan]

I'm actually going to reopen this issue because making things exception-safe requires both code changes in this repository and an update to the article's wording.

[Michael-F-Bryan]

aaanndd it's closed again 😛