Automatic From impl
This change automatically derives From conversions for variants or structs if
- There is a single binding, and
- That binding has the #[cause] attribute
This is a breaking change, as it will conflict with any existing manual From implementations.
In my opinion, having this on by default seems best, so I would personally prefer to wait for a breaking release than change this default behavior.
If it is desirable to have an opt-out of the from impl, I can probably add that. That said, I can't see any reason why for something with a single field you wouldn't want the automatic impl.
I've also added some documentation and made sure all tests are passing (had to remove a couple From impls in the test files).