Add Write::by_ref

[yoshuawuyts]

Ref #131, implements Write::by_ref. Thanks!

References

• https://doc.rust-lang.org/std/io/trait.Write.html#method.by_ref

[yoshuawuyts]

Oh dang yeah; I just remembered the conversation with @dignifiedquire and while this method can be implemented, it cannot be called.

Which is to say: there's no way to disambiguate between Read::by_ref and Write::by_ref because you'd have to write:

WriteExt::by_ref(f)

Which isn't valid. This needs to be an inherent method on AsyncRead and AsyncWrite in order for it to work. We should probably PR futures-io for this.

[ghost]

We should also add the same method for Read and Stream :)

[yoshuawuyts]

@stjepang oh yeah Read already has this, but Stream doesn't -- you're right we should add it! We probably can't merge this PR as-is though; this is something that should be part of futures-core because of the reasons I mentioned above 😞