I know. But for me personally, the `io::Reader` and `io::Writer` is still not comfortable enough. Mainly because it's return values, `io::Error` to be specific. Because I found that in many of my cases, predefined `io::ErrorKind` is not enough for me, this results my abuse of `io::ErrorKind::Other`.

In Go, `error` is an interface that can later be asserted, so I can return any `error` then deal with them as late as I need.

This gives me ability to write some complex `io.Reader` and `io.Writer`. For example, an `io.Reader` that can Decode data stream, and returns both CodecError and IoError when it encountered any.

In Rust, if I want to write a similar thing, a HPACK decoder that returns both `io::Error` and `HPACK::DecodeError` for example, I need come up with another `Result` type that wraps both errors. This can sometime be tiring and makes the code inflexible (As one simple change to the `Result` may effect the entire call chain up and down).

BUT ... Maybe it's Go's fault, it treats me too well, make me want something that I cannot have for free (performance cost) else where.

> In Rust, if I want to write a similar thing, a HPACK decoder that returns both `io::Error` and `HPACK::DecodeError` for example, I need come up with another `Result` type that wraps both errors. This can sometime be tiring and makes the code inflexible (As one simple change to the `Result` may effect the entire call chain up and down).

Well there's stuff like error-chain to take care of the boilerplate...

Also, I believe you could define the equivalent of Go error in Rust as a trait and box it (ie. a trait object). It could be used much the same way as in Go with the additional benefit of Result being a sum type. I'm personally not a big fan of this approach but I guess it might work...

> you could define the equivalent of Go error in Rust as a trait and box it (ie. a trait object).

I know this basically how Go's error handling works (Put error data on heap and pass the reference), but I'm not fan of it (the put data on heap part of it) too :(

I will try out the error-chain, thank you for reminding me that.

The “failure” crate is an alternative to error-chain as well.