Add get_ref() and get_mut()

[zinid]

Under some circumstances get_mut() is required (e.g. to add more data to the underlying buffer).

Same with get_ref().

[est31]

There is ways around, like using Rc in combination with *Cell or friends but I suppose this is simpler for you. Could you add a note that all bets are off when you are using these functions, like it is the responsibility of the caller to ensure the data is consistent?

[zinid]

@est31 I do exactly this now: using Rc + RefCell. However this is not enough and I have to implement the Seek + Read traits, because they are not "proxied" through RefCell and Rc, which makes the code even more convoluted.

But I digress 😄

I added a safety comment to get_mut() as you requested 😄 As for get_ref(), I think adding a note about the caller's responsibility to ensure data consistency is generally unnecessary because get_ref() only returns an immutable reference to the underlying reader.

[est31]

get_ref() only returns an immutable reference to the underlying reader.

If you have Cell around then an immutable reference is enough. Same goes for file descriptors. But whatever, I've merged this.

[zinid]

Thanks a lot!

Any chance we get this updated in crates.io? 😄