impl<Inner> From<Inner> for Context<Inner>

[est31]

I am personally trying out now a light variant of the custom Error + ErrorKind approach, where I have an ErrorKind but instead of a custom Error I just use type MyError = Context<MyErrorKind>;.

This works great for the usual from impl's but it doesn't help when I want to return try!(Err(ErrorKind::SomeKind)) directly.

Therefore I think it would be great to always have From<Inner> implemented for Context<Inner>. Right now I have to do try!(Err(Context::new(ErrorKind::SomeKind))) instead, or impl the from myself, but neither are nice things to do :).

[withoutboats]

I think I just didn't think about doing this! I don't think there is any coherence issue. I'm for it, and I've tagged this issue help wanted :)