Cannot move io::Error out of Peekable Result - error-handling

Question

I'm just trying to propagate the IO error:
enum MyError {
EOF,
IO(std::io::Error),
}
fn peek_byte<R>(mut p: Peekable<Bytes<R>>) -> Result<u8, MyError>
where
R: Read,
{
match p.peek() {
None => Err(MyError::EOF),
Some(Err(e)) => Err(MyError::IO(*e)), // <==== error is here
Some(Ok(byte)) => Ok(*byte),
}
}
But, I get the following error:
error[E0507]: cannot move out of `*e` which is behind a shared reference
--> src/main.rs:17:41
|
17 | Some(Err(e)) => Err(MyError::IO(*e)),
| ^^ move occurs because `*e` has type `std::io::Error`, which does not implement the `Copy` trait
I actually understand all of this. I know why I'm getting the error, and what the error means. What I don't know is how to accomplish my task and propagate the IO error into my error type.
I have tried e, *e, e.clone(), *e.clone(), *(e.clone()), but they all either produce a "type mismatch" or a "cannot move" error.

Answer 1

The Peekable iterator holds ownership of the next value of its internal iterator and returns references via peek, but if you actually want the owned value you just call next as usual (which does advance the iterator but I think that's okay in this case since you're not actually consuming any content from the iterator but just trying to return an error):
use std::io;
use std::io::Bytes;
use std::io::Read;
use std::iter::Peekable;
enum MyError {
EOF,
IO(io::Error),
}
fn peek_byte<R>(mut p: Peekable<Bytes<R>>) -> Result<u8, MyError>
where
R: Read,
{
match p.peek() {
None => Err(MyError::EOF),
Some(Err(e)) => Err(MyError::IO(p.next().unwrap().unwrap_err())),
Some(Ok(byte)) => Ok(*byte),
}
}
playground