`cast::Error` does not implement `Error` trait

[japaric]

`cast::Error` does not implement `Error` trait

[emk]

As a workaround, people using error-chain can add something like the following their errors module:

impl From<cast::Error> for Error {
    fn from(err: cast::Error) -> Error {
        format!("numeric cast error: {:?}", err).into()
    }
}

[japaric]

Would you be interested in a pull request adding support for this to your cast library?

Sure!

[emk]

Could you please assign this to me using the Issues interface so that I don't lose track of it? Thank you! I'm juggling a bunch of Rust PRs the next couple of days.

[japaric]

@emk Done!

[emk]

OK, I've submitted the PR #9, which should provide Error (and several other useful impls). There's an interesting complication because Error requires std and not core, but I provided a way to build the library either with or without core. See the PR for details.

Thank you for your quick response the other day! This is a very useful crate, and I'm going to encourage my coworkers at Faraday to make this part of our standard coding style!